AN ANALYTICAL STUDY
of
HF COMMUNICATIONS
between
PROVINCIAL PREOC’s
and the
NORTH SHORE EMERGENCY
MANAGEMENT OFFICE
at VE7NSR
JOHN WHITE VA7JW
March 2010
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COVER PAGE
The cover page is an IONOGRAM. It is created by an instrument called an IONOSONDE.
These instruments are located at many locations worldwide and continuously measure
ionospheric parameters. A simplified ionogram is illustrated,
The vertical axis is km above the earth’s surface and the horizontal axis is frequency in MHz.
The data is created by transmitting an RF signal straight up into the ionosphere. The transmitter
sweeps the test signal frequency across the HF spectrum, typically 1 to 10 MHz. The ionosphere
returns the signal straight back down to a receiver as in an echo. It is the echo which is being
plotted.
Time is measured between the transmitted and received signal to determine the height of the
ionosphere at each frequency. There is a lower frequency below which no echo is returned due to
absorption, and there is an upper frequency beyond which the ionosphere will not be able to
return the signal. This is where the trace takes a very steep upwards turn. These frequencies
will vary throughout the day, over the seasons, over the 11 year sunspot cycle, and all by latitude.
foF2, the Critical Frequency, is very important to HF propagation and is a key parameter in this
study. h’F2, the height of the ionosphere (hmF2 in this study), is another important parameter.
The cover page is a real Ionogram. The Black Line is plotting the ionization density which peaks
at about 4.325 MHz at a height of about 230 km when this report was captured on 10 August
2009 at 21:33:30 UTC. This peak corresponds to the hmF2 layer at about 230.1 km. The E layer
hmE can be spotted at about 100 km as a small dip in the black line plot.
The fainter colored areas are secondary returns from the primary refracted signal being reflected
off the earth back up again.
In the data column on the left are the numerical values for the various ionospheric parameters. A
Glossary of terms is included in Appendix II of this report.
To view such a real time IONOGRAM, visit the HAARP DIGISONDE at the ionospheric
observatory in Gakona Alaska.
http://137.229.36.56
Under Public Center, click on Latest Ionogram.
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NOTICE
This study has not been commissioned or sanctioned by any organization or special interest
group. It is a personal study undertaken by the author completely on his own initiative to satisfy
his curiosity regarding the subject matter. No payments were involved.
Thanks to
David Shipman VE7CFD/VA7AM for his work in extracting the ionospheric data from the Boulder
and Gakona web sites, creating the Excel propagation calculators, and for reading through this
study. Adam Farson VA7OJ, Nick Massey VA7NRM, Brian Austin G0GSF for providing
comments, corrections and critical technical review, to Roy Lewallen W7EL (EZNEC) for
supporting the antenna analysis effort, and to Logan Hart VE7HL for arranging printing of this
study.
All the PREOC contacts for providing information on their station equipments.
Brady Conroy
Joe Rieberger
Frank VanderZande
Kevin Hartley
James Longley
Glenn Grieve
VE7TAX
VE7CRJ
VE7AV
VE7OVY / VA7FE
VE7JMS
VE7CNQ
Kamloops
Nelson
Prince George
Saanich
Surrey
Terrace
About the Author
John White, VA7JW first licenced in 1959 as VE7AAL, has been an active amateur since then.
Particularly interested in HF SSB operating, he has HF/VHF/UHF stations operating from the
home QTH. The station details can be viewed at www.QRZ.com. Educated at UBC Electrical
Engineering, 1965. Professional Engineer telecommunications, now retired. Worked for Lenkurt
Electric, MPR Teltech, Digital Courier, Glenayre and Norsat International. Member, North Shore
Amateur Radio Club, BCDX Club, RAC, ARRL.
Contact Information
Telephone Home 604-936-2367
Cell 604-802-8367
va7jw@shaw.ca
Edition 1
Copyright © John White VA7JW
Many of the figures use color to convey information. Distributed hard copy is printed in grey scale
to reduce cost. A colored .PDF of this report in color may be downloaded from www.nsarc.ca >
Tech Archives > HF_PREOC_Study > Report. Please contact the author for permission to
reproduce any of this material.
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SUMMARY
HOW TO READ THIS REPORT
For those not technically interested, read only Section 1.7, RECOMMENDATIONS.
For those who desire some understanding of this study, read Section 1, BASICS.
For those who wish to understand the technicalities, read Section 2, TECHNICAL DETAIL.
This study examines the ability of Provincial Regional Emergency Communications Centers
(PREOC’s) to communicate using the 80 meter amateur radio high frequency (HF) band.
It is NOT an overall study of all ways or means of radio communications between PREOC’s,
particularly via VHF/UHF directly, or via repeaters. However some information on VHF/UHF is
recorded in the PREOC equipment profiles and in Appendix X.
The two significant factors affecting HF communications are the propagation modes and the
choice of antennas.
HF Communications between PREOC’s depends on the state of the ionosphere and its ability to
return a sky wave signal back to earth at a distance. As the ionosphere is a highly variable entity,
communications are not assured.
Ground wave propagation, as an alternative to ionospheric propagation, is also investigated.
The North Shore Amateur Radio Club (NSARC), VE7NSR, located in the North Shore Emergency
Management Office (NSEMO) in North Vancouver B.C. is used as a reference point for this study.
Its ability to communicate to other PREOC’s is of interest. As well, the overall radio – antenna
set-up at NSARC is fairly representative to other EOC’s and so comparisons can be made.
Various antennas, particularly dipoles and verticals, are modeled to determine their radiation
characteristics and suitability for either, or both of, ionospheric sky wave and ground wave
propagation being independent of the ionosphere.
While there is no possibility of manipulating the state of the ionosphere to our benefit,
understanding the behavior of the ionosphere will be beneficial to operators in determining their
choices for operational frequencies (40 meters, 80 meters or 160 meters) and the timing of those
operations. Knowing the characteristics will aid in those choices and possibly extend the
windows of communication.
While antenna choices can be optimized depending on the communications requirement, they
cannot overcome the limitations of the ionosphere.
PREOC’s within the province rely on medium distance (0 to 1000 km) ionospheric
communications. Other PREOC’s and municipal EOC’s grouped within the lower mainland and
Vancouver Island will find both ionospheric propagation and possibly ground wave useful.
Recommendations are provided regarding antenna types according to both modes of
propagation. Information, resources and Web pages are provided throughout to aid in
determining current ionospheric conditions as well as other related topics and tools.
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SECTION 1 – BASICS
Section 1 provides Basic Information to support the Findings and Recommendations
1.1
PROGAM PLAN
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
Overview
PREOC Profiling
Propagation
Antennas
Conclusions
1.2
PREOC’s
1.3
SKYWAVE PROPAGATION
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5
1.3.6
Overview
The Ionosphere
Sky Wave
Near Vertical Incident Skywave (NVIS)
Critical Frequency
Maximum Useable Frequency
1.4
GROUND WAVE PROPAGATION
1.5
ANTENNAS
1.5.1
1.5.2
1.5.3
Reference Antennas
The Dipole as an NVIS Antenna
The Vertical as a Ground Wave Antenna
1.6
FINDINGS
1.6.1
1.6.2
1.6.3
1.6.4
1.6.5
1.6.6
1.6.7
Ionospheric Propagation
Ground Wave Propagation
Dipole and Inverted VEE Antennas
NVIS Considerations
Vertical Antennas
Ground Wave vs NVIS Sky Wave
HF vs VHF
1.7
RECOMMENDATIONS
1.7.1
1.7.2
1.7.3
1.7.4
1.7.5
1.7.6
1.7.7
1.7.8
1.7.9
160 m Band
Propagation Education
Operations Guide
NVIS Antennas
Vertical Antennas
Digital Modes
WinLink
NSEMO Vertical VEE
NSEMO GAP Vertical
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1.1
PROGAM PLAN
1.1.1
Overview
Seasoned HF operators are well versed in the variability of band “conditions” and the frustration
of not being able to establish reliable HF communications to specific locations. If emergency
traffic has to be communicated, HF becomes problematic.
The question arises - “what can be done to improve the effectiveness of HF communications
between PREOC’s within the province”.
This study has been assembled using analytical techniques to determine the propagation
mechanisms that exist between the Provincial Emergency Operations Centers (PREOC’s) within
British Columbia.
The methodology consists of 1) cataloging the HF equipment at the PREOC’s, 2) gaining an
understanding of the propagation mechanisms, and 3) determining what antenna systems may
be best for supporting those propagation mechanisms.
The study therefore examines three main areas of interest,
A) The PREOC’s, their locations, their equipment and antennas.
B) Propagation mechanisms between PREOC’s, both Sky Wave and Ground Wave.
C) Antennas suitable to support both modes of propagation.
1.1.2
PREOC Profiling
A survey of each PREOC was done to determine HF equipment capability. A summary of the
equipment profiles for each of the PREOC’s is presented as well as information with respect to
their geographic locations.
1.1.3
Propagation
The study examines the primary mechanisms of propagation specific to the need, both by
ionospheric sky wave and non-ionospheric ground wave.
Specifically, the study focuses on the propagation characteristics of the 80 meter band, most
commonly used for intra provincial communications. The 160 m and 40 m “low” bands, being
either “side” of the 80 m band can by extension be considered suitable candidates.
Frequency bands of 20 meters and up (in frequency), the “high” bands, are not suitable for intraprovincial communications due to their long skip characteristics, and so are ignored.
1.1.4
Antennas
Four types of antennas are examined, the Dipole and a related variant, the Inverted VEE,
Verticals, and another variant, the Vertical VEE. These antenna systems will enable
communication by Ionospheric Sky wave and Ground Wave.
1.1.5
Conclusions
Findings are summarized to address lessons learned, and from these, Recommendations are
provided for consideration.
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1.2
PREOC’s
The six B.C. PREOC’s are,
Location
Primary Call Sign
Technical Contact
Email Address
Kamloops
Nelson
Prince George
Saanich
Surrey
Terrace
VE7KAZ
VE7NEZ
VE7PGZ
VE7PEP
VE7SWF
VE7NWZ
Brady Conroy
Joe Rieberger
Frank VanderZande
Kevin Hartley
James Longley
Glenn Grieve
brady.conroy@domtar.com
jrieberger@cintek.com
frankvdz@telus.net
ve7ovy@telus.net
ve7jms@rac.ca
glenn_grieve@hotmail.com
A map of the province is provided in Section 2.4.1 showing the location of the cities and primary
call signs of each PREOC.
A table listing the Latitudes and Longitudes of each location is provided in Table 2.4.2-1 and
distances between each PREOC in km is contained in Table 2.1.8-1.
Section 2.4.3 provides street address and a satellite view of each PREOC and resource contacts.
Section 2.4.3 also lists their HF equipment profile as required for this study. This includes
transceivers, antennas, AC power sources, repeaters and their links are profiled and allows us to
understand each location’s communications capability.
While not part of the study, the opportunity presented itself to complete the equipment profiles of
the PREOC’s by cataloging the VHF and UHF equipment and capability as well.
To summarize the status of the PREOCS, ALL have,
1
2
3
4
5
Modern, all band, multi mode, HF transceivers of 100 Watts.
WinLink capability with Pactor modems.
Antennas for 80 and 40 m.
Backup AC power.
SSB as the primary mode.
Most centers have multi-band dipoles covering 80 through 10 m. Others have more than one HF
antenna such as yagi’s, rotate-able dipoles or more than one dipole.
There are only two centers with vertical antennas.
None of the centers indicated that they use RTTY or PSK.
1.3
PROPAGATION
1.3.1
Overview
Propagation describes the path taken by a radio wave that travels through space from a
transmitter to a receiver.
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There are two mechanisms by which HF signals will propagate between stations.
The first is by Sky Wave and the second is by Ground Wave. These two mechanisms are further
explained in following sections.
The transmitters’ antenna radiates a radio wave that travels upwards and outwards. That which
directs energy skyward best describes a sky wave antenna while that which directs energy
outwards along the surface of the earth is described as a Ground Wave antenna.
The radio wave will travel, that is, propagate through the atmosphere, from a transmitter to a
receiver. Note that radio wave propagation at HF frequencies (1 to 30 MHz) is not affected by the
atmosphere or by the weather.
1.3.2
The Ionosphere
The atmosphere simplistically consists of approximately 75% nitrogen and 25% oxygen
molecules. As one travels vertically upwards through the atmosphere, the air becomes thinner or
more rarified. At these higher altitudes the ultraviolet radiation from the Sun becomes more and
more intense with altitude because there is less air to attenuate the radiation.
At heights starting at about 80 km, the ultraviolet radiation is sufficiently energetic to “knock off”
an electron from either a nitrogen or oxygen molecule. This removal of an electron creates an
ion, that is, a molecule with an electron deficiency, and a free electron that is able to “float” freely
in the rarified air. This process carries on through the upper atmosphere up to about 700 km
where there is little to no air left to ionize.
The rather thick layer of ionized air above us is the ionosphere, not to be confused with the
Ozone layer. Diagrams to follow will show that the ionosphere is characterized by regions, by
height, known as the D, E and F layers. We are only concerned with F layer propagation in this
study as it is the most useful layer.
A radio wave that is radiated upwards from an antenna eventually reaches the ionosphere.
Because the radio wave is an electromagnetic wave, it interacts with the free electrons in
complex ways, the net effect being to bend the radio wave back down to earth. It appears that
this is a reflection, but it is actually a refractive process, that is, the ray is continuously bending
downwards towards earth as it travels through the ionosphere, and ends up exiting the
ionosphere headed towards earth as though it were reflected.
The ability of the ionosphere to refract a radio signal back to earth depends on the ionization
density which is totally dependent on the ionizing energy received from the Sun. Obviously, day
time and night time will cause the ionosphere to behave differently. Ionization occurs on the sunlit side of the planet and de-ionization occurs on the dark side of the planet. De-ionization occurs
naturally as the free negative electrons re-combine with their positive ionized parent ions to
restore an electrically neutral molecule. This accounts for hourly to daily variations in the state of
the ionosphere. Season affects the ionosphere as well as the radiation is more direct in summer
than winter, and the Sun also goes through an 11 year solar cycle of more and less intense
radiation.
There is one more factor to take into account. The ionosphere has an upper limit to the highest
frequency it is able to refract back to earth. At the best of times, long distance communications
can be accomplished on frequencies as high as ~ 30 MHz but most of the time it is very much
less. All of the time, it will always dependent on the moment by moment conditions on the Sun,
as well as the usual day to night, seasonal, and solar cycle variations.
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1.3.3
Sky Wave
Sky wave signals are radiated outwards and upwards and are the prime mechanism for over the
horizon communications. This long distance propagation takes place since the radio wave
intercepts the ionosphere at some distance from the transmitter and is returned to earth at a
much further location as can be seen in the figure below. This gives rise to the ability to
communicate over great distances. The ability to propagate over the horizon is often referred to
as Skip as the signal can skip over long distances.
Figure 1.3.3-1
Sky Wave
Notice that the higher angle radiation may pass through the ionosphere and be lost to space.
This is because the ionosphere is not sufficiently ionized to fully refract the signal back to earth.
Note that signals may NOT be heard in the skip zone that lies underneath the point of refraction.
This can be a considerable distance, such as the entire province. This situation would make
intra-provincial contacts impossible. Fortunately, this is not the case as explained in Section
1.3.4.
Refer to Section 2.1.3 for an explanation of the D, E and F layer labels.
1.3.4
Near Vertical Incident Sky Wave (NVIS)
If the radio wave directed straight upwards from the ground to the ionosphere, it is possible for it
to be refracted straight back down again. This is referred to as Near Vertical Incident Sky wave –
NVIS –propagation.
Figure 1.3.4-1
NVIS Return
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NVIS
Oblique
180 o
Oblique
120 o
90 o
Figure 1.3.4-2
Return Angles
Observe that an NVIS signal has to be refracted through a demanding 180 degrees! A Skywave
at an oblique angle will require less bending (refraction) to be returned. NVIS propagation is very
important as it allows stations close together, i.e. within the lower mainland, and those further out
in the province, but within the skip zone, to communicate ionospherically.
Loss of NVIS propagation will result in impairment or loss of intra-provincial communications.
1.3.5
Critical Frequency
With respect to the previous figure showing a vertically propagated signal being returned to earth,
there is a maximum frequency limit to this signal. This is referred to as the Critical Frequency.
The ability to achieve a180 degree return depends on the ionization density. If the ionization is
relatively lower, then the critical frequency is lowered. If ionization is higher, the critical frequency
increases.
During December, 2009, during which the critical frequency was randomly monitored, the critical
frequency was typically about 1.9 to 2 MHz at 6 pm local time, and the B.C. Public Service Net on
3.729 MHz was seriously impacted.
If the critical frequency is 4 MHz or higher, propagation on the 80 meter band will be supported as
the ionosphere will return all frequencies less than that. If the critical frequency falls below 4
MHz, NVIS propagation on 80 meters will begin to fail. This happens with sunset as the
ionization process ceases causing the critical frequency to diminish. This is commonly observed
on the BC Public Service Net which can start off with all stations hearing a lower mainland /
Island Net control but as the net progresses, stations close to Net Control will find that Net
Control is lost although stations further way may still be heard.
Critical Frequency is the single most important parameter in determining if a band is open or
closed.
Lack of activity on a band does not always mean the band is closed; consider those bands that
seem dead until a contest starts. The band will often come alive with stations not commonly
heard. Operators (VE7FO) who monitor beacons will also find that a band is open in spite of no
activity. Of course, a quiet band may also in fact be dead. However, for NVIS communication
purposes, checking the critical frequency will confirm the band condition.
1.3.6
Maximum Useable Frequency - MUF
As de-ionization begins towards sunset, NVIS can be lost. So how is it that more distant stations
may continue to remain strong? The signals from these stations, being distant, will be
intercepting the ionosphere at a less than vertical angle, and the ionosphere does not have to
refract the signal through a 180 degree return angle. This means that the 80 m signal that could
not be returned vertically can be returned for refraction angles of less than 180 degrees, such as
the 128 degrees required from the lower mainland to Kamloops.
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As ionization further decreases, a lower and lower oblique angle is required sustain the refraction
to complete a successful return. Seasoned operators refer to this phenomena as the “band going
long” meaning the skip distance increases as ionization decreases, and more distant stations are
heard as closer stations disappear.
1.4
GROUND WAVE PROPAGATION
A radio wave that travels directly outwards from the antenna, that is, horizontally toward the
horizon, is referred to as a Ground Wave.
The ground wave is capable of providing communication between “local” stations that are NOT
over the horizon.
Ground wave does not depend on the ionosphere for its path; it travels along the surface of the
earth. None of the variations listed as influencing the ionospheric sky wave have an effect on the
ground wave and so the propagation path is stable, repeatable and reliable. However, the wave is
rapidly attenuated and large obstructions such as big buildings, hills and mountains may create
shadow zones but on the other hand, propagation over water is good such as lower mainland to
Vancouver Island. This mode has to be tested and verified as to its range and usefulness.
Note that Polarization of the radio wave means everything to the success of ground wave
propagation. Antennas radiating vertically polarized waves are required for this purpose.
1.5
ANTENNAS
1.5.1
Reference Antennas
Appendix I models three simple antennas that would be appropriate for intra-provincial
communication. These are the Dipole, the Inverted VEE which is a closely related variant of the
dipole, and the quarter wave vertical, all for 80m and at various heights. These would be
considered ideal antennas to which real antennas may be compared.
At VE7NSR, located at the North Shore Emergency Management Office, the only suitable
antenna for intra-provincial communications is an Inverted VEE. It has been modeled in its
particular environment and performance differences noted. There is no Vertical installed at this
location. A new antenna is proposed, a Vertical VEE, which is not yet implemented, but, has
been modeled to determine its usefulness at VE7NSR. There is no reference antenna for this
design.
1.5.2
The Dipole as an NVIS Antenna
A Dipole antenna, or Inverted VEE constructed low to the ground, provides excellent NVIS
service. They typically have radiation patterns as shown in Figure 1.5.2-1 showing that most of
the energy is radiated upwards, some outwards, and little to none horizontally.
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Typical NVIS Vertical Radiation Plot of a Dipole Antenna
Figure 1.5.2-1
This would be the typical vertical radiation pattern for an 80 meter dipole at a quarter wavelength,
~ 65 feet, or less above ground.
Most amateur installations, including all PREOC’s, have their 80 meter dipoles at less than this
height, making them NVIS antennas by default.
They exhibit sufficiently effective radiation at angles down to ~ 35 degrees which makes them
appropriate for intra-provincial, sky wave propagation.
1.5.3
The Vertical as a Ground Wave Antenna
Vertically polarized ground wave is much less attenuated than horizontally polarized ground
wave. In fact it is difficult to develop a horizontally polarized ground wave as the radiation pattern
from an 80 meter NVIS dipole has very little radiation at low angles.
The best antenna for generating a vertically polarized ground wave is the quarter wave vertical
antenna mounted at ground level. This antenna directs energy straight out in a horizontal pattern
which is ideal for ground wave. No energy is directed upwards and so this antenna is of no use as
an NVIS source.
This antenna may be useful for PREOC’s and EOC’s within their common horizon, as in the lower
mainland and possibly across the water to Vancouver Island EOC’s. Testing is required, vertical
to vertical to confirm.
Figure 1.5.3-1
Typical Vertical Radiation plot of a Vertical Antenna
The overall low angle of radiation is NOT suitable for intra-provincial communications as will be
seen in Section 2 where the path geometry between distant (over the horizon) PREOC’s is
typically higher than 30 degrees, whereas the vertical has little radiation at angles higher than 30
degrees.
Note the dotted line in Figure 1.5.3-1 which indicates that attenuation of the signal does occur at
very low angles due to ground losses.
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1.6
FINDINGS
1.6.1
Ionospheric Propagation
Low band, 160, 80 and 40 meter HF communication capability is provided by ionospheric means.
This limits communications to narrow windows of opportunity throughout the day which may not
be favorable for emergency communications. Two windows exist, the morning hours from just
before sunrise + perhaps 2 hours after, and late afternoon, perhaps 1- 3 hours prior to sunset and
for 1 - 3 hours after sunset. Even these windows are not guaranteed and may not exist at all.
Determination of the Critical Frequency (Appendix III) will confirm to an operator whether
communication is possible or not.
The 160 m band does not appear to be a band of consideration for PREOC communication. It
would however seem to be a candidate as the critical frequency is not often below 2 MHz thereby
offering extended hours of communications when 80 m closes.
The 40 m band suffers from a lack of NVIS propagation as the critical frequency has to exceed
7.3 MHz to ensure close in propagation. This band is acceptable for short skip in the mid to later
afternoons. The likelihood of NVIS will be higher in the more active periods of the solar cycle.
1.6.2
Ground Wave Propagation
Vertically polarized ground wave is independent of ionospheric conditions and will behave
consistently and reliably over distances within the horizon.
It will not provide communications between over-the-horizon PREOC’s.
When NVIS fails, vertical ground wave may be useful as it provides propagation within line-ofsight range.
Vertically polarized Direct Space Wave propagation may provide communications between
PREOC’s, EOC’s and HF mobile units within their common horizon. This applies to areas such as
the lower mainland, and within, but not between, other urban centers on a provincial scale.
Polarization matching is imperative. If EOC’s are going to communicate with each other or
individuals with mobiles, or mobile command posts, both “ends” must have vertical antennas.
Horizontal to Vertical will not work at all well as cross polarization loss can exceed 20 dB.
There will be instances where both Direct Space Wave and NVIS are both effective in which case
the effects of fading or nulls may exist due to destructive interference. Operators should switch
antennas to take advantage of the dominant mode, that is, vertically or horizontally polarized
antennas.
PREOC’s in mountainous locations will find limited use for Direct or Surface wave.
1.6.3
Dipole and Inverted VEE Antennas
Wire dipoles and VEE’s are seen to be most effective antennas for low band (160, 80 and 40
meters) communications.
All PREOC’s have 80 meter and 40 m antennas, but no 160 m dipoles for this purpose.
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The Dipole and Inverted VEE can provide an excellent radiation pattern to support the NVIS and
short skip conditions. To achieve this characteristic, the dipole should not be higher than about
0.3 wave lengths above ground.
As suggested in Section 1.6.1, 160 m dipoles may offer extended openings. However, they are in
the order of 265 feet long and would take up much more space raising installation issues. Multiband dipoles for 160, 80 and 40 m could be considered to take full advantage of easy band
switching as the critical frequency decreases during later afternoon through evening hours.
Trapped 160/80/40 m dipoles can be under 200 feet as the presence of the traps will shorten
overall length, and they do not necessarily need external ATU’s; rig tuners will suffice. Examples
may be found at,
Spi Ro Antennas
Unadilla / Reyco
http://www.spiromfg.com/index.htm
http://www.unadilla.com/
End fed long wires can be used effectively for NVIS as well with an ATU and an efficient
counterpoise, being a wire as long as the antenna wire. An earth ground will be very much less
effective.
1.6.4
NVIS Considerations
NVIS provides communications routinely on the 160, 80 and 40 m bands.
NVIS is the most important HF propagation mode for intra-provincial communications (0 to 1000
km).
NVIS uses the ionospheric F layer with high angle antenna radiation. However, angles as low as
35 degrees are needed within B.C. An Inverted VEE has a somewhat better low angle compared
to a Dipole, being 3 to 6 dB better according to models in this report.
NVIS antennas are optimized for high angles of radiation and simple, inexpensive dipole style of
antennas can be used to achieve the desired effect.
NVIS antennas are purposely mounted low to the ground, somewhere between 0.1 and 0.3
wavelength. This eases construction issues.
NVIS antennas are not directional. They radiate equally well over 360 degrees at the high angles
and so can be erected in any direction.
NVIS antennas work well in valley-constrained environments as the radiation is more up than out.
1.6.5
Vertical Antennas
Vertical antennas are required to generate vertically polarized ground wave.
Horizontal dipoles generate horizontally polarized signals that are rapidly attenuated at the earth’s
surface.
Effective communication using vertical polarization between stations requires that BOTH stations
use vertical antennas. If they communicate using cross polarized antennas, i.e. a vertical
communicating with a horizontal, there will be significant cross polarization loss typically seen as
15 to 20 dB.
Vertical antennas are not effective for communicating with PREOC’s that are over the horizon as
their radiation angles are too low for the angles required (> 30 degrees) for short skip into other
provincial centers.
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HF mobiles within ground wave range of a PREOC / EOC will undoubtedly be using vertical
whips, and so for local ground wave communications to any local PREOC / EOC, a vertical
antenna is required at the EOC to avoid the cross polarization loss from their dipole.
PREOC locations probably have little space to mount a vertical on the ground that includes a
significant radial system, and the area is likely surrounded with many obstructions such as
metallic buildings that would shadow or distort the low angle radiation.
Most typically for PREOC’s, elevated verticals would be mounted on buildings and may or may
not have ground plane systems. Regardless, raising a vertical antenna results is the
development of high angle radiation lobes, depending on height, and rob the low angle radiation
of gain as seen in Appendix I. Keep raised vertical systems to less than ¼ wave length above
ground.
1.6.7
Ground Wave vs NVIS Sky Wave
Table 1.6.7-1
1
Comparison of Ground Wave and NVIS Sky Wave Characteristics
1.6.8
HF vs VHF
Obviously if VHF/UHF repeaters are in operation, they would be the preferred mode for
communications within or beyond the urban area. In the worst case, if repeaters are not
functional, then point-to-point communications is needed. VHF/UHF is attenuated very rapidly
and so HF, being much less attenuated, may prove to be the only option.
1
HF Communications, Nicolas Maslin. Pitman,1987
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1.7 RECOMMENDATIONS
1.7.1
160 M band
The Critical Frequency is less likely to fall below 2 MHz than 3.7 MHz, thus providing a greater
window of operating time. Use band down-switching in evenings 40 > 80 > 160 or up-switching in
morning 160 > 80 > 40 m. Establish a 160 m net frequency. Modify antennas to operate on
160m.
1.7.2
Propagation Education
Educate HF emergency operators as to the mechanisms that affect propagation. Provide
software tools, such as DX Atlas, for the prediction of conditions.
1.7.3
Operations Guide
Develop a GUIDE as to best times for low band communications based on time of day / season /
sunspot cycle. The Guide to be common to all PREOC’s so all operators literally read off the
same page.
1.7.4
NVIS Antennas
PREOC HF antennas for 80 m and 40 m need only be simple dipoles or Inverted VEE’s. There is
no need to mount more than one-quarter wavelength above ground (< 66 feet at 80 m).
Directionality is minimal under these circumstances. NVIS antennas mounted above industrial
style buildings with a large metal roof structure will likely have the radiation pattern disturbed but
unless modeled, there is no way of knowing exactly how that might be. Generally it appears that it
will augment NVIS
1.7.5
Vertical Antennas
Do not elevate quarter wave vertical antennas or vertical dipoles more that 1/8 wavelength above
ground as they will start to lose significant low angle radiation.
Communications with local mobiles (typically constrained to vertical whip antennas) requires EOC
vertical antennas to avoid cross-polarization losses. Trials with vertical systems would be
worthwhile to prove or disprove their worthiness.
Verticals mounted on large metal roof structures will likely have the radiation pattern disturbed but
unless modeled, there is no way of knowing the extent to which that may occur. Refer to
Appendix I to view the high angle lobe growth with height.
1.7.6
Digital Modes
No station declared RTTY or PSK mode capability. Encourage PREOC’s to install RTTY and
PSK to cope with poor signal to noise conditions. These applications (MMTY, Ham Radio
Deluxe) are free and easy to operate. It will require computers with rig control and audio
interfaces.
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1.7.7
WinLink
This mode is standard equipment at all PREOC’s and is probably the most capable digital mode.
Anecdotal inferences indicate that it is not easy to use and few know how. Status to be confirmed
and tested regularly on net frequencies, all stations, with trained operators.
1.7.8
VHF/UHF Systems
To achieve independence of HF variability, determine the extent to which PREOC stations can be
linked through existing repeater systems on a provincial scale. Many wide area repeater systems
exist in the North and East and on the Island. Build out the systems so all PREOCS can be
linked. Refer to Appendix X for known systems.
Of particular interest to VE7NSR / NSEMO
1.7.9
Vertical VEE
Build the Vertical VEE, Section 2.3.8, at NSEMO for test purposes. Test for Mobile
effectiveness in the lower mainland. Test vertically polarized ground wave between NSEMO
and Surrey and Saanich PREOC’s using the Inverted VEE, and the experimental Vertical VEE.
Other test sites may include the Island.
1.7.10
GAP Vertical
From an emergency operation perspective, erecting the GAP or any other traditional vertical
radiator will not be pursued by the author due to the predicted high angle of radiation and poor
directionality in this instance.
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SECTION 2 – TECHNICAL DETAIL
Section 2 provides Detailed Technical Material in support of this study
2.1
Ionospheric Propagation
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.1.9
2.1.10
2.1.11
2.1.12
2.1.13
2.1.14
Snell’s Law of Reflection
Refraction in the Ionosphere
Ionospheric Layers
Critical Frequency
Vertical and Oblique Skywave
Maximum Useable Frequency
Ionospheric Height
MUF and Distance
Ionospheric Observatory Data
Simple MUF Calculator
Sky Wave Geometry
Signal to Noise
Absorption
Minimum Frequency
2.2
Ground Wave Propagation
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
Ground Wave Model
Surface Wave
Frequency Dependence of Surface Wave
Direct Space Wave
Polarization
Radio horizon
Locations within Sight
Distribution of Ground Wave and Sky Wave Signals
2.3
Antenna Models
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10
Antenna Modeling Software
Reference Antennas
NSEMO VEE Antenna and Spatial Orientation
Reading EZNEC Plots
Inverted VEE – No Roof
Inverted VEE with Roof
Proposed NSEMO Vertical Antenna
Proposed NSEMO Vertical VEE
Comparative Signal Strength
Comments
2.4
PREOC Data
2.4.1
2.4.2
2.4.3
Location of PREOC’s by Map
Detailed PREOC Location Data
Equipment Profile by PREOC
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SECTION 2 – TECHNICAL DETAIL
2.1
IONOSPHERIC PROPAGATION
2.1.1
Snell’s Law of Reflection:
Referring to Figure 2.1.1-1, where a reflecting surface exists, the Angle of Reflection of a light ray
or radio wave, as measured from the Normal, equals the Angle of Incidence, also as measured
from the Normal.
NORMAL line
Perpendicular to the Reflecting Surface
Reflecting Surface
Incident
Angle of
Incidence
Angle of
Reflection
Reflected
Figure 2.1.1-1
Snell’s Law
2.1.2
Refraction in the Ionosphere
To an observer, the ionosphere looks like a reflecting surface per Figure 2.1.2-1, as the incident
and reflected waves behave in accordance with Snell’s law.
However, the radio wave is not reflected; it is refracted back to earth, refraction being the
continuous bending of the radio wave back to earth as it passes through the ionosphere.
Ionosphere
Virtual
Reflecting
Surface
Real Path
Virtual Path
f incident
Tx
Virtual
Heigth of
Reflection
"hmF2"
f refracted
Earths Surface
Rx
Figure 2.1.2-1
Earth – Ionospheric Refraction Geometry
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For simplicity, we can model the refraction as a reflection, as shown by Figure 2.1.2-1 by using
the “virtual path” concept.
Note that there is no actual reflecting surface as illustrated since the radio wave is continuously
being bent back towards earth within the ionosphere. This imaginary reflecting surface
represents the effective height of the ionosphere for modeling purposes.
This virtual, reflecting, ionospheric height is referred to as “hmF2”, hm being the maximum
effective height and F2 the most important refractive layer of the ionosphere.
Refer to the graphs of Appendix IV for the variation of hmF2 with time according to
measurements provided by the Boulder CO. and Gakona AK. observatories.
As the radio wave is propagated skyward as f Incident, it is refracted back to earth some distance
away as f Refracted. This provides the mechanism for communication over long distances.
2.1.3
Ionospheric Layers
Besides the F layer, there are two lower layers, the D and E.
The F layer splits into two layers during the daytime, the F1 and F2. They recombine during
darkness into the singular F layer. The F2 layer is used in this study.
The D layer is the lowest layer at about 50 km and does not refract signals; it absorbs signals and
so is considered lossy. It only exists during the daytime under intense radiation when the sun is
above the horizon and it dissipates at sunset. See also Section 2.1.13.
The E layer, at about 80-100 km, is refractive but does not play a part in this propagation study as
it has a very low critical frequency as well as low altitude and dissipates shortly after sunset.
2.1.4
Critical Frequency
As mentioned in Section 1.3.5, the critical frequency is the highest frequency that will be returned
to earth by the ionosphere when the radio wave is launched straight upwards.
The critical frequency is referred to as “foF2”, fo being the vertical incident frequency and F2
being the most important refractive layer of the ionosphere.
Refer to the graphs of Appendix IV for the variation of foF2 on a daily, monthly and yearly basis
according to measurements provided by the Boulder CO. and Gakona AK observatories.
If the Critical Frequency is higher than the desired communication frequency, f incident, then the
ionosphere is capable of returning the signal, f refracted, to earth for all antenna take-off angles
from 0 to 90 degrees.
However, if the Critical Frequency is less than our desired communications frequency, f incident,
signals being propagated straight up will not be returned to earth, will penetrate the ionosphere,
and will be lost to space.
The Critical Frequency foF2 is the most important parameter in this study. It is measured world
wide by various ionospheric observatories and is typically published on the web every 15
minutes, 24 x 7. It is not a constant value and it varies throughout the day, the season, and
during the 11 year Sun Spot cycle. It may typically lie be between 2 and 12 MHz.
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2.1.5
Vertical and Oblique Sky Wave
There is a relationship between the vertically propagated critical frequency, foF2 sky wave, to a
sky wave frequency which is launched at a lower angle.
A sky wave launched at a lower angle, and at a frequency higher than foF2, can be returned to
earth. In fact, the lower the launch angle, the higher that frequency can be for a successful
return. This is because the ionosphere does not have to refract the sky wave through such as
great an angle associated with high angle sky wave, Figure 1.3.4-2.
Referring to Figure 2.1.5-1, f signal is launched from earth’s surface at angle dependent on the
antenna characteristics. This wave is incident on the ionosphere at the oblique angle  . Note
that for the vertically launched foF2, is 90 degrees and is 0 degrees.
Constructing the signal paths as a right triangle allows us to calculate angles and the related f
signal, being the length of the hypotenuse, the critical frequency foF2 being the vertical line, with
the base being the distance over the earth’s surface.
Ionsphere
ig
foF2
fs
Oblique
Angle
l
na
90 degrees
Take-Off Angle
Earth surface
Figure 2.1.5-1
Triangular Geometry
Referring to the angles in Figure 2.1.5-1, and as the takeoff angle decreases, the oblique angle of
the sky wave, as it approaches the ionosphere, increases. As this angle increases, the amount of
refraction required to accomplish a return to earth is less.
Further, if we apply basic trigonometry rules relating the take-off angle of the sky wave, , to the
take-off angle of the critical frequency, foF2, being 90 degrees, we get,
Sin = foF2 / f signal
Rearranging the formula,
F signal = foF2 / Sin 2
Jacobs & Cohen, page 14, Equation (1),
Mathematically this says that as take off angle gets smaller, f signal becomes larger because
foF2 is divided by a smaller number.
In other words, a lower angle of radiation will result in a frequency higher than the critical
frequency foF2 being returned to earth.
2
Shortwave Propagation Handbook, Second Edition 1982. CQ Publishing. See also Ionospheric Radio, Kenneth Davies.
National Bureau of Standards, 1965. Page 161 equation (a)
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2.1.6
Maximum Useable Frequency - MUF
Equation (1) shows that as the take-off angle of the signal becomes lower and lower, the higher
and higher the operating frequency can become.
The highest frequency that is likely to enable communication, at a certain angle, over a certain
distance, is referred to as the Maximum Useable Frequency or MUF.
For a given take-off angle , and given foF2, there will be a MUF for that angle. As decreases,
the MUF increases. Knowing the MUF is essential to determining if communication is possible.
As an example, foF2 may be 2.9 MHz indicating that the 80 meter band is “closed”, that is, not
able to support propagation on 3.7 MHz. This is not true. The 80 meter band will not support
NVIS propagation, but it will support propagation to some distant point with a lower take-off angle
of the sky wave from the antenna. Hence, a station in the lower mainland may readily hear
stations, say on 3.729 MHz, that are out-of-province to the east such as Alberta, Saskatchewan
and Manitoba since the MUF for such a lower angle would be 3.729 MHz or higher.
These calculations are NOT precise due to the highly situational state of the ionosphere. MUF is
generally considered to define the likelihood of communication for 50% of the time, that is, for one
half the time, the MUF could be lower or for the other half of the time, higher. However, variable,
this phenomenon is key to enabling High Frequency (HF) radio communications to cover local to
worldwide distances.
2.1.7
Ionospheric Height
The height of the ionosphere changes in the same fashion as the critical frequency, and may
typically vary between 150 and 350 km. This parameter is measured and reported by the same
ionospheric observatories as the critical frequency hmF2. See Appendix IV.
Equation (1) by itself, while illustrating the relationship between foF2 and the MUF offered by a
lower take take-off angle, is somewhat incomplete as the distance covered is not predicted. This
would require knowledge of the effective height of the ionosphere.
As per section 2.1.2, the virtual height, hmF2 is measured along with all other ionospheric
parameters and so this information is readily available to compute the “skip”, or hop distance “D”.
Referring to Figure 2.1.7-1, skip distance “D” is measured over a flat earth. The space between
the transmitter “Tx” and the receiver “Rx” is considered one “hop”. A listener “L” in between Tx
and Rx may not hear Tx as the take off angle may too high to effect a return. Of course, if NVIS
is in play, L will hear T. Note that earth’s curvature has not been taken into account. For the
distances involved in this study, being < 1000 km, the error is not terribly important.
Virtual Reflecting Surface
Virtual Height
foF2
hmF2
L
Tx
Distance D
Rx
Figure 2.1.7-1
MUF, Skip Distance and Height
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It is obvious that the launch angle , the height hmF2 of the ionosphere, the distance “D” along
the surface of the earth, the critical frequency foF2 and the MUF are geometrically related.
2.1.8
MUF and Distance
The relationship between the distance “D”, the height of the ionosphere hmF2, the critical
frequency, foF2, and the MUF is given by,
MUF = foF2
√ 1+ [D/(2hmF2)]2 Davies3
This requires knowledge of foF2, hmF2. These can be looked up on-line from the observatories
per Section 2.1.9 or with software recommended in Appendix III. The distance D between the
stations desiring to communicate has to be known as well. Table 2.1.8-1 provides the calculated
distances between PREOC’s using the Lat / Long., and W6EL to calculate “D”, Section 2.4.2.
NSEMO
NSEMO
Surrey
Saanich
Kamloops
Nelson
P George
Terrace
24
84
234
418
510
689
80
239
400
523
711
318
456
591
748
258
391
696
619
951
Surrey
24
Saanich
84
80
Kamloops
234
239
318
Nelson
418
400
456
258
P. George
510
523
591
391
619
Terrace
689
711
748
696
951
383
383
Table 2.1.8-1
Distances in km between PREOC’s
The MUF formula will calculate the MUF. Whether it is sufficient is another matter, mostly
dependent on foF2, and with a probability of 50%.
2.1.9
Ionospheric Observatory Data
Ionospheric data has been gathered from two observatories, Boulder CO. and Gakona AK. A
sample of the data format from Boulder follows on the next page as Table 2.1.9-1,
3
Kenneth Davies, “Ionospheric Radio Propagation” National Bureau of Standards, Ed 1 April 1965. Chapter 4.3, Eq 4.14
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:Product: Boulder_iono.txt
:Issued: 2009 Dec 17 2155 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
# Please send comments and suggestions to SWPC.Webmaster@noaa.gov
#
# Units for foF2, MUF(D), ٛ oes, foE, fMUF, foF1, fxI & fbEs = MHz
# Units for yF2, D, hmE, h’F, h’ & hmF2 = km
# Units for TEC = 10^16 el/m^2
# Missing data: -1.0,-1,-1.00
#
#
Real-Time Ionosonde Data
#
Boulder N40E255 AFRL-DGS-256
#
# UT Date
Time
# YR MO DA HHMM
foF2 hmF2 MUF(D) D h’F yF2 fMUF h’ fxI foF1 foE hmE foEs fbEs ITEC
#------------------------------------------------------------------------------------------2009 12 16 0000
3.5 -1 3.54 3000 200 55 3.2 270 4.2 -1.0 -1.0 -1 -1.0 -1.0
2.6
2009 12 16 0015
2.9 -1 3.37 3000 226 85 2.5 275 3.7 -1.0 -1.0 -1 2.4 -1.0
2.0
2009 12 16 0030
-1.0 -1 -1.00 3000 -1 -1 -1.0 -1 -1.0 -1.0 -1.0 -1 -1.0 -1.0 -1.0
2009 12 16 0100
2.1 -1 3.74 3000 245 20 2.0 275 2.9 -1.0 -1.0 -1 2.4 -1.0
0.3
Table 2.1.9-1
Ionospheric Data Table
The first two columns provide the critical frequency foF2 and the height of the ionosphere hmF2.
If you read -1 as hmF2 does in this example, it means that the data is missing for that time slot.
This data is available on-line from Boulder at,
http://www.swpc.noaa.gov/ftpdir/lists/iono_day/Boulder_iono.txt
Data collected from Gakona Alaska is at,
http://www.swpc.noaa.gov/ftpdir/lists/iono_day/Gakona_iono.txt
Reading and understanding the various parameters provided in these reports is beyond the
scope of this study, but explanations can be found in Appendix II or at,
http://spidr.ngdc.noaa.gov/spidr/help.do?group=Iono
As B.C. lies about one half the distances between each of these observatories, data from both
were averaged for calculations relating to those parameters used in this study, namely foF2 and
hmF2.
Data has been downloaded from these two sites and is stored in a large Excel ® data base
created for this study. It contains 1 years worth of data (Sept 08 through Oct 09) for parameters
of interest, and graphs can be plotted to show daily and seasonal variations. Another data base
has 10 years of data to measure variations over the last sunspot cycle (2001 to 2009).
2.1.10 Simple MUF Calculator
Using the data from 2.1.9, a MUF calculator was built in Excel ® to calculate the MUF required to
provide communications between PREOC’s (or any other designated locations defined by
distance, at any frequency).
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Units
DETERMINE MUF
Yellow fields are data entry. Green fields are computed values
1. Enter Critical Frequency foF2
3.5
MHz
2. Enter F2 virtual layer Height hmF2
250
kilometers
3. Enter Distance "D" between Stations
690
kilometers
4. Enter Net Frequency "Fn"
3.735
MHz
5. MUF Available
5.965
MHz
Take Off Angle
6. Take Off Angle
35.9
Table 2.1.10-1
MUF Calculator Presentation
The YELLOW fields are data entry. One must specify all 4 of these parameters to calculate MUF.
The MUF will display with a GREEN field if the MUF exceeds the “Net Frequency”, meaning
communication is (likely) supported at that frequency. If the MUF displays a PINK field, the MUF
is NOT sufficiently high enough to support communication.
foF2 and hmF2 can be derived from either of the ion.txt links per Section 2.1.9 or by using the DX
Atlas / Ionoprobe software, Appendix III.
The calculator is also used to calculate the take-off angle from the antenna for the particular path
chosen.
To make use this calculator, please go to,
http://www.nsarc.ca/ > Tech Archive > HF_PREOC_Study > Ionographs
Go to file: Simple_MUF_Calculator.xls
2.1.11 Sky Wave Geometry
The attached figure is used to illustrate the path geometry between VE7NSR in North Vancouver
and the PREOC’s in the province. The drawing is to scale.
A full size 11” x 17 “down loadable PDF file is available at
www.nsarc.ca/ > Tech Archive > HF_PREOC_Study > Ionographs
Go to file: PREOC-path-geometry.pdf
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Notes
350
1. Illustrative for a typical height of F2 Layer (hmF2) at 6pm local time.
2. Analysis is for 80 meter at 3.735 MHz nominal .
3. When the Crtical Frequency foF2 > 3.735 MHz, NVIS propgation is mathematically possible to all locations.
3. When foF2 < 3.735 MHz, NVIS begins to fail for closest in stations as MUF falls below 3.735 MHz .
4. As foF2 decreases further with de-ionization, only stations further out will be heard and even those may eventually be lost.
5. MUF for stations at various distances is calculated given foF2, hmF2 , distance to stations and the PEP frequency.
325
300
hmF2 Ionospheric Height km
275
hmF2 ~ 250 km
250
PEP Net Frequency 3.735 MHz
225
foF2 = 3.5 MHz
200
Location
Surrey
Saanichton
Kamloops
Nelson
Prince George
Terrace
175
150
Angle
88 degrees
80 degrees
64 degrees
50 degrees
44 degrees
35 degrees
MUF
NVIS
3.502 MHz
3.544 MHz
3.840 MHz
4.400 MHz
4.502 MHz
5.615 MHz
No
No
No
No
No
No
Path
No
No
Yes
Yes
Yes
Yes
125
100
75
50
~ Surface Wave vertical
polarization distance limit
for VE7NSR
25
Surrey
24 km
0
0
Kamloops
234 km
Saanichton
84 km
50
100
150
200
250
Prince George
510km
Nelson
418 km
300
350
400
450
500
Terrace
689 km
550
600
650
700
750
Origin is VE7NSR / NSEMO Location
SURFACE DISTANCE BETWEEN PREOC's & VE7NSR in km
Figure 2.1.11- 1
Path Geometry – NSEMO to PREOC’s
2.1.12 Signal to Noise
The amount of noise at the receiver is the limiting factor in any communications. If the noise
level, natural or manmade, is equal to or exceeds the desired signal level, the signal will become
difficult to impossible to copy.
Figure 2.1.12 -1 provides a guideline as to the expected noise levels in various environments.
Figure 2.1.12-1
ITU-R PI.372-6
Man-Made Noise Levels 2-20 MHz
For instance, in a Residential (urban) environment, the 80 meter band (~ 4 MHz) can be expected
to show an RF field strength of ~ +8 dB V / meter which is 2.5 V / meter. For an 80 meter
dipole, this level of field strength will induce about 27 V at the antenna terminals. This is would
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read about S8 on a receiver S meter. At the author’s location this is about right, typically the
noise level runs at about S8 to S9. At VE7NSR, the noise levels are about 1-2 S points higher,
presumably due to the proximity of the station to Lions Gate hospital which is suspected of
generating high levels of unintentional RF radiation due to electronic medical systems.
These calculations require knowledge in the conversion of field strength measured in db V /
meter (level in dB above or below 1 V /meter) to actual V /meter. V / meter is field strength,
not antenna voltage. There is an Antenna Factor that is required to convert V / meter to Volts
at the antenna terminals. This process is described in Appendix VII.
2.1.13 Absorption
The ionosphere is not lossless. An electromagnetic wave passing through the ionosphere is
attenuated by absorption. Absorption depends on the degree of ionization density which is
greatest in the D layer, and is at a maximum at noon local time, maximum in the summer, and
maximum at the peak of the sunspot cycle. Because of the high air density in the D layer,
recombination of wave energized electrons with their parent ions occurs quickly and signal is
lost. Ionization is only sustained due to the Sun’s continued radiation.
If the wavelength of the incident frequency is long compared to the recombination distance, then
recombination occurs more frequently, and greater loss is incurred. As wave length decreases,
less energy is lost.
Absorption varies inversely as the square of the frequency. Relatively speaking, a signal at 3.5
MHz incurs losses 16 times (10 Log(16) = 12dB) more than that of a signal at 14 MHz.
Absorption accounts for the fact that the low bands, 160, 80 and to some extent 40 m are signal
quiet during the main daylight hours, becoming more active towards sunset and becoming less
active after sunrise. They become most difficult at the times of maximum absorption to the extent
communications may not be possible. Note that the skywave has to make two passes though the
D layer overall in returning to earth. This accounts for the lower frequencies being known as the
“night time” bands. Refer to the Absorption graph in Appendix IV.
The higher frequencies, 20 m and up are able to penetrate the D & E layer and are refracted by
the F layer. This accounts for the higher frequencies being known as the “daytime” bands.
2.1.14 Minimum Frequency
Absorption does set an ultimate lower frequency limit that governs sky wave propagation. This is
reported as fmin from the ionospheric observatories.
Again, the observatory sends a signal straight up and looks for a return. At some low frequency,
no signal is returned as it is completely absorbed. The lowest returned frequency is fmin.
If your operating frequency is lower than fmin, propagation will fail. Refer to Appendix IV graphs.
Note that fmin is also a function of transmitted power. Consider that an Ionosonde has measured
fmin at 1.5 MHz. This is the frequency at which the transmitted frequency is on the verge of total
absorption, and an incrementally lower frequency will not be returned due to incrementally higher
absorption. However, if the transmit power is increased by say 10 dB, an echo may well be
returned at an incrementally lower frequency if the attenuation is say only 8 dB greater. However,
the reduction in fmin is minimal in our context. This effect also governs on skip where ionospheric
losses occur as the wave is refracted back to earth. The usual remedy is to increase transmit
power to overcome weak signal at the receiver.
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2.2
GROUND WAVE PROPAGATION
2.2.1
Ground Wave Model
The other propagation mode for HF is non-ionospheric Ground Wave.
The Ground Wave consists of two components; a Surface Wave propagated along the surface of
the earth and a Direct Space Wave that propagates above the immediate surface.
Figure 2.2.1-1
4
Components of a Ground Wave
2.2.2
Surface Wave
The surface wave has a tilted front characteristic which is due to the interaction of the field and
the imperfect conductivity of the earth. Surface wave propagation can be visualized as “clinging”
to the surface of the earth and following the contours. Signal may be propagated well beyond the
horizon in this mode.
5
As an example, the LORAN-A marine navigation system operated on “our” 160 m band. These
stations provided coverage over the Pacific Ocean, well over the horizon, to ~ 140 degrees west
6
or approximately 500 miles off the West coast .
2.2.3
Frequency Dependence of Surface Wave
7
The effective range of a surface wave is frequency dependent as given in Figure 2.2.5-1 . With
reference to this figure, note that at 160m, the surface wave distance capability approaches 2
MHz asymptotically and implies extended distances may be realized at this, and lower
frequencies.
The Medium Frequency (MF) band (300 kHz to 3 MHz), which includes the AM broadcast band,
starts just below the 160 m band. MF is characterized by weak skywave with a strong
dependence on ground wave. During darkness, ionospheric propagation does occur as the
8
critical frequency is usually greater than 2 MHz. However, ionospheric absorption remains high
with significant temporal issues related to interference between ground wave and sky wave.
The HF (3 to 30 MHz) spectrum, while not considered ground wave useful, is fortunate to have
tremendous skywave capability. The transition between MF where ground wave is the dominant
propagation mode, to HF skywave where ionospheric propagation dominates, is around the 2
MHz region.
4
Radcom. December 2009. Antennas, Pages 52, 53. Figure 7
http://www.jproc.ca/hyperbolic/loran_a.html
6
http://www.jproc.ca/hyperbolic/lorana_coverage_map_1950b.jpg
7
ARRL Antenna Handbook, 19th Edition. Page 23.5, Figure 3
8
Ionospheric Radio, Ken Davies IEE Electromagnetic Waves Series 31May 1989. Chapter 11, Section 11.1 and 11.2.
5
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20 m 40 m 80 m
31 mi 44 mi 55 mi
160 m
80 mi
Figure 2.2.3-1
Surface Wave Distance as a Function of Frequency
2.2.4
Direct Space Wave
Direct space wave forms a line-of-sight, point to point communication path. It does not suffer the
same attenuation as the surface wave.
2.2.5
Polarization
Antennas that are oriented parallel to the surface of the earth will radiate horizontally polarized
electromagnetic waves. Antennas that are vertically oriented to the surface of the earth will
radiate vertically polarized electromagnetic waves. It is the electric field orientation that defines
the polarization.
A horizontally polarized surface wave is rapidly attenuated as it travels over the earth’s surface
since the electric field is virtually short circuited by ground conductivity. Horizontal propagation
over salt water is attenuated to a much greater extent.
A vertically polarized surface wave does not suffer attenuation to as great an extent since the
9
electric field is at right angles (vertical) to the ground and no interaction takes place . As the
ground is not magnetic, the magnetic field which is parallel to the surface of the earth is
unaffected.
2.2.6
Radio Horizon
Direct space radio waves travel as Line-of-Sight to and beyond the optical horizon due to
10
diffraction along the earth’s surface. The distance is frequency dependent .
If the two antennas are in sight of each other, the direct space wave will form the point to point
communication link as it is less attenuated than the surface wave.
The Radio Horizon and Optical Horizon are not quite the same as the radio wave can propagate
about 30% (4/3) further due to the ground effect which bends the direct space wave down as it
10
travels over the surface . This creates a Radio Horizon.
9
http://en.wikipedia.org/wiki/Radio_propagation, Surface Modes.
ARRL Antenna Handbook, 19th Edition. Chapter 23, “The Ground Wave”. Pages 23-4, 23-5
10
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For instance, at NSEMO, the Radio Horizon is given by,
D = 1.415 x √ (H)
11
where H = height above sea level in feet
and D = distance to radio horizon in miles
The ground elevation at NSEMO is 104 m / 341 feet.
that,
H = 341 + 50 = 391 feet
12
Assume the antenna is 50 feet above
D = 28 miles to the radio Horizon
The receiving station also has a distance, D1, to its radio horizon.
.
Figure 2.2.6-1
13
Distances to Radio Horizon, Transmitter to Receiver
The total communications path length is then (D + D1).
2.2.7
Locations Within Sight
Due to NSEMO’s location on the upward slopes of North Vancouver, much of the lower mainland
is optically visible. From the roof, line of sight exists from the West through the South to East
South-East. The Straits of Georgia are plainly visible as is Vancouver Island and the Gulf
Islands. Table 2.2.4-1 indicates certain locations of interest that can “see” each other.
Height “H” is an estimate based on Google Earth elevations at town center plus a 15 m antenna
height allowance. However it is not known if an EOC even exists or what its altitude might be.
11
ARRL Antenna Handbook, 19th Edition. Chapter 23, Page 23-5, Equation 3
Google Earth
13
ARRL Antenna Handbook, 19th Edition. Chapter 23, Page 23-6, Figure 5
12
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Height H
D
D1
D + D1
Actual
feet incl Ant
miles
mies
miles
miles
NSEMO
391
28.0
Surrey
358
26.8
54.8
14.9
Yes
Land, no obstructions
Qualicum
221
21.0
49.0
59.6
No
Salt water; Brtiish Prop 171m; Qualicum rise 64 m. Distance limited
Nanaimo
148
17.2
45.2
42.8
Marginal Salt water, Stanley Park 25 m
Ladysmith
162
18.0
46.0
39.7
Marginal Salt water, Valdez 85m & Yellow pt 63m obstructions
Chemainus
148
17.2
45.2
40.4
Marginal Salt water, Galiano 33m & Thetis 50m obstructions
Duncan
102
14.3
42.3
46
No
Salt Water, galiano 135 m; Saltspring 235 m; Maple Bay 247m. Distance and
obstruction limited
Saanich
257
22.7
50.7
52.2
No
QE Park 109 m, Salt Water, Mayne 102 m. Distance & obstruction limited
Victoria
148
17.2
45.2
64.6
No
Oakrifdge 80m, Salt Water;Mayne 37m, South Pender 105m. Uplands 60m.
Distance and obstruction limited
Location
Horizons
Meet?
Path Obstructions Noted
Reference Reference Location
Figure 2.2.7-1
Locations within Sight of Each Other including Obstructions
Direct Space Wave will likely work in the lower mainland on 80 and 40 m but the tall building
clutter surrounding NSEMO is acute which may render direct space and ground wave unusable in
certain directions. This will have to be tested to verify usefulness.
Direct Space Wave might work to the common radio horizon indicated by the “YES” cells
although it also is subject to testing. Marginal is anyone’s guess. The “NO” cells exceed the
Radio Horizon and are not expected to provide a useable path. Test anyway.
In any case, for the Vertical Polarization mode to work at all well, antennas at both ends of the
circuit MUST be verticals. Communication between a vertical at one end and a horizontal dipole
at the other end will suffer a cross-polarization loss, typically 20 dB, which is unaffordable.
2.2.8
Distribution of Ground Wave and Sky Wave Signals
A study performed with a Rohde & Schwartz direction finding antenna system operated by the
Dutch Radiocommunications Agency in the center of the Netherlands was able to measure the
14
incoming angle of 80 m signals. A scatter plot is shown in Figure 2.2.5-1
Figure 2.2.8-1
Ground Wave – Sky Wave Elevation Angles
14
Radcom. June 2005. “Elevation Angle Measurements for NVIS Propagation”. Pages 76 ff.
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Interestingly, ground wave extends out to about 25 miles which implies horizon limited direct
space wave. At the time this data was recorded, NVIS was obviously active as very high angles
were also received, from close in, at the same time.
2.3
2.3.1
ANTENNA MODELS
Antenna Modeling Software
All antennas have been modeled using W7EL, Roy Lewallen’s EZNEC antenna modeling
application, Version 3.0. This software package, now at version 5.0, retails for $89 US and can be
ordered online.
http://www.eznec.com
EZNEC.EZ files for antennas modeled in this study can be found at www.nsarc.ca > Tech
Archive > HF_PREOC_STUDY > Antenna Models
2.3.2
Reference Antennas
Appendix I models three reference antennas, the dipole, the inverted VEE and a quarter wave
Vertical for 80 m operation. The height of the antennas is varied to show changes in radiation
patterns with height.
These three were chosen as they are the most suitable candidates to meet the propagation
requirements of NVIS sky wave and vertically polarized ground wave. These models will serve
as a reference point for real antennas that will undoubtedly have altered characteristics.
For instance, VE7NSR at NSEMO has an Inverted VEE that has a horizontal 97 degree apex
angle rather than 180 degrees. It is also mounted above a large conductive plane, i.e. the steel
roof. The feed point is higher than what would be optimum for an NVIS antenna. Differences
between the reference VEE and the VE7NSR VEE will become apparent and can be judged as
acceptable of detrimental to the required performance. Other EOC’s will undoubtedly have their
own installations to consider.
2.3.3
NSEMO VEE Antenna & Spatial Orientation
The VE7NSR / NSEMO VEE antenna will be used to illustrate a real antenna installed on a
building but constrained in its shape by the physical nature of the building.
The NSEMO building is of concrete and steel construction with a metal Q-Deck structural roof
under the asphalt roofing material. The antenna is constructed to scale on a scale drawing of the
NSEMO roof. A coordinate system is required to construct the antenna models. The North East
corner of the building is chosen as the origin of the coordinate system that will be used to build
the models.
This origin is also important, not only for constructing the antenna accurately with respect to the
building, but for establishing a reference system that can extend to distances over the lower
mainland and Vancouver Island.
This is important since field strengths need to be computed at other PREOC’s within the horizon
of NSEMO. Orientation of the antennas and their radiation patterns must be fixed with respect to
the NSEMO transmit site and the receiving PREOC site.
The Origin for the frame of reference is X = 0, Y = 0, and Z =0 feet above street level.
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The X axis is true WEST; the Y axis is true SOUTH. North and East are fixed true as well.
X
FEEDPOINT
North East Corner
Coordinate System Origin
EZNEC ORIGIN COORDINATE
X=0
Y=0
Z = 45 ft
Inverted VEE location
Y
True North
West
East
South
BREWER BUILDING FOORPRINT
Figure 2.3.3-1
NSEMO Building Outline with Inverted VEE Antenna Position Illustrated
NSEMO roof in X dimension ~ 210 feet, Y dimension ~ 146 Feet, and Z roof level is ~ 45 ft above
street level.
The antenna is built of wires entered into an EZNEC wire table. The wire ends are described in 3
dimensional space, that is an X, Y, and Z coordinate keyed to the building coordinate system
origin.
This is an example of the inverted VEE on the NSEMO roof. X is pointing WEST, Y is pointing
SOUTH, Z is the elevation, and 1 and 2 are the two wires of the inverted VEE. The red dot at the
wire junction is the feed point.
X = West
Y = South
Figure 2.3.3-2
EZNEC Antenna Structure within the EZNEC Coordinate System
However, the metal roof of the building cannot be ignored as it is of significant dimensions
compared to the wavelengths under consideration. (80 m 265 feet). The effect of this large
metal plane needs to be investigated.
The metal roof is built in EZNEC as a conductive wire grid of 150 ft x 200 ft. at 45 feet above
street level ground. This is the final model used for determining antenna radiation characteristics.
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Plan View
Perspective View
Figure 2.3.3-3
Metal Roof Modeled as a Wire Grid, with Inverted VEE Antenna
2.3.4
Reading EZNEC Plots
Based on the antenna construction as shown above, EZNEC computes the Azimuth and
Elevation radiation patterns, as well as SWR, Impedance, Polarization, Field Strength and other
parameters.
A ) Azimuth Plot
This plot shows the radiation pattern for the full 360 degrees at a specific Elevation Setting.
AZ Cursor
Setting
AZ Cursor
Dot
EL Cursor
Setting
Figure 2.3.4-1
Typical EZNEC Azimuth Plot
Note that the Azimuth Cursor is set to 0 degrees and the Elevation Cursor is set to 80 degrees.
EZNEC automatically assigns the EL position to the vertical angle of maximum radiation.
The AZ plot may change significantly at other EL settings and so one has to set the EL to a
meaningful value. As well, the AZ plot may change significantly at other AZ settings.
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One has to carefully examine the radiation characteristics in both the AZ and EL plots with
various settings of AZ and EL to extract meaningful results.
For AZ plots, the following relates the EZNEC plot & cursor settings to TRUE compass direction.
o
Y = South = 90 Cursor
Y
EZNEC axis orientation
X
o
o
East = 180 Cursor
X = West = 0 Cursor
o
North = 270 Cursor
Figure 2.3.4-2
True Compass Directions
B) Elevation Plot
This plot shows the vertical radiation pattern for angles from 0 to 90 degrees (horizontal to
straight up) at a specific Azimuth setting.
At the given AZ setting, EZNEC defaults to the maximum gain elevation. Read the data panel
associated with the AZ – El plots to determine the precise figures.
The GREEN line is the point of maximum vertical radiation, 80 degrees; the two purple lines are
the – 3dB (half power) points of the pattern.
Axis of
AZ setting
Figure 2.3.4-3
Typical EZNEC Elevation Plot
Since the AZ cursor is set to 0 degrees, the pattern is that along the X Axis as shown above.
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2.3.5
Inverted VEE – No Roof
In order to compare the NSEMO Inverted VEE antenna performance, an Inverted VEE antenna
has been constructed to the same dimensions and orientation as the NSEMO inverted VEE,
above ground with a feed point height of 110 ft (45ft + 65 ft) but without the roof structure.
The AZ cursor is placed South since the lower mainland and Vancouver Island are to the South of
NSEMO and this direction is therefore of interest. EZNEC automatically places the EL cursor at
the elevation of maximum gain. It can be seen that the pattern actually favors roughly South,
South East and North, North East. This is probably due to the apex angle distortion, being
approximately 97 degrees instead of 180 degrees.
Also plotted are the radiated polarizations, Horizontal Polarization (HP) is Blue, Vertical
Polarization (VP) is RED and the Total Field (TF) is BLACK.
It may be counter intuitive to think that a dipole antenna could radiate a vertically polarized field.
However, a perfectly straight and level dipole has significant VP off each end of the dipole along
the dipole axis, reducing to zero when directly off the side. Similarly, the HP reduces to zero off
the axis ends. As one moves off the dipole axis, both the HP and VP fields need to be computed
at each point in space to determine the level of each polarization.
S
W
Figure 2.3.5-1
AZ EL Plots for Inverted VEE without Roof
2.3.6
Inverted VEE with Roof
The Inverted VEE is then placed above the building roof to the actual location with the feed point
being 65 feet above the roof plus 45 feet above real ground; the wire ends are about 8 feet above
the roof. The NSEMO VEE is neither symmetrical nor centered on the roof top and so the wire
grid is not symmetrical with respect to the antenna.
The model shows that the effect of the metal roof is to somewhat distort the radiation pattern with
respect to the reference VEE. The Inverted VEE over the highly reflective metal roof actually
appears to have made the AZ plot much more symmetrical, almost ideal. However at lower EL
angles the AZ plot changes. At 50 degrees it is egg shaped and at lower angles, quite distorted.
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S
W
W
Figure 2.3.6-1
AZ EL plots for NSEMO Inverted VEE
The vertical radiation pattern of the VE7NSR Inverted VEE is placed over the take off angle
geometries necessary to communicate with the other PREOC’s.
INVERTED VEE VERTICAL RADIATION PATTERN to PRECO's
Surrey 88 degrees
Saanichton 80 degrees
Kamloops 64 degrees
Nelson 50 degrees
Prince George 44 degrees
90 deg
Terrace 35 degrees
75 deg
60 deg
45 deg
30 deg
Radiation Angles to PREOC's contained within
35o to 90o and Gain within 0 to -3 dB
15 deg
0
0
50
100
150
200
250
300
Figure 2.3.6-2
Inverted VEE Take Off Angles to PREOC’s
Even though this antenna has a rather high feed point (110 ft / 0.4 wavelength) making it a less
than an ideal NVIS antenna, it is evident that even at the lowest take-off angle, the gain is only
down ~ 3 dB or 1/2 “S” point. The metallic roof appears to have little detrimental effect on the
NVIS performance, and may in fact enhance the high angle radiation.
This is an ideal NVIS antenna as well as supporting short intra-provincial skip with take off angles
down to ~ 35 degrees. Low angle radiation below ~ 20 degrees, is however limited to nil.
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The last calculation is performed using the EZNEC Near Field feature. EZNEC can calculate the
magnitude of the vertical and horizontal electric field at any distance by using the NF (Near Field)
tab on the EZNEC control center. W7EL, the author of EZNEC advises by email,
“..You can use the “Near Field” analysis in EZNEC to evaluate ground wave
field strength at any distant point. “Near Field” analysis isn’t
actually restricted to the near field, but is valid at any distance.
The strength of the Horizontal field for both the Ex and Ey direction and the Vertical field Ez are
calculated at the Surrey PREOC center. Refer to Appendix VIII for the details of this calculation.
The results are per Table 2.3.6-1,
Table 2.3.6-1
Inverted VEE Far Field Plot at Surrey PREOC
At 20 feet, the vertical field at ~ 42 V / meter about 17 dB greater than the horizontal field. This
is likely due to the horizontally polarized wave being more susceptible to ground attenuation than
the vertically polarized wave.
As an aside, the NSEMO Inverted VEE, while modeled at 3.75 MHz is actually cut for the 160
meter band, not the 80 meter band, as are the reference models. The SWR is > 100:1 for this
VEE on 80 m! SWR does not affect radiation pattern but does affect the ability of the transmitter
& coax feed line to couple energy into the antenna due to the horrendous mismatch. This is
overcome by the use of a remote antenna tuning unit (ATU) an SGC -230, located near the
antenna. The ATU output is connected to about 50 feet of 450 ohm ladder line to the feed point of
the VEE, and so all forward power is actually coupled into and radiated by the antenna. This is a
multi-band antenna good for 160 m through 10 m
2.3.7
Proposed NSEMO Vertical Antenna
VE7NSR does not have a roof mounted vertical antenna although it does possess a GAP Titan
multi-band vertical that could be roof mounted.
The GAP is impossible to model as it is a complex assembly. However, it is approximated as a ¼
wave vertical monopole on 80 m for the purposes of this study, even thought this is not practically
possible. Appendix X shows that a loaded, short vertical dipole yields much the same result as a
vertically mounted half wave dipole.
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The vertical would be placed on the roof just as the Inverted VEE was modeled over the roof. The
roof acts as a large, non-resonant ground plane. The feed point, for modeling purposes is
connected between the vertical and the roof acting as the ground plane. This model is, of course,
elevated at 45 feet above street level “ground”.
It is noted that the GAP does not require a ground plane or a radial system. The manufacturer
suggests that the antenna be mounted 6 to 8 feet above such a metal structure.
The length of the vertical was set to 61 feet to equal one quarter wave length at 80 m. EZNEC
shows this to be resonant at 2.5 MHz, not 3.75 MHz. Since radiation patterns are not determined
by SWR, the model is left to resonate at 2.5 MHz even though the reason is not known.
S
W
AZ Plot
South EL plot
East EL Plot
Figure 2.3.7-1
AZ EL Plots for Proposed Vertical Antenna
North–South Current Null Axis
Figure 2.3.7-2
Current Distribution in Roof Grid
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The influence of the NSEMO roof ground plane has a very detrimental effect on the radiation
pattern of this vertical. As seen in the Vertical Antenna Reference in Appendix I, the growth of
high angle lobes has developed as a result of its height above ground.
Again, W7EL, again advises
“ … the building roof influences only the high angle radiation, because
that’s all that reflects from it. Lower angle radiation travels beyond
the roof and reflects off the ground some distance away.”
Also noticed is the development of horizontal polarization which appears unexpectedly in the
South AZ plot.
The South AZ plot has an 18 dB null which is problematic as is it desired to have a good pattern
from the SE through to the West to serve greater Vancouver and possibly lower Vancouver
Island. These nulls along the “Y” axis appear to be a result of the “X” dimension of the roof
showing a current null in the North - South “Y” direction.
These plots are not encouraging for the use of a vertical antenna to provide low angle radiation
for vertically polarized local communication.
NOTE: EZNEC version 3.0 (authors version) has been used to estimate the far field strength at
low angles of radiation. It does not model the ground wave components. The modeled fields
would be considered as Direct Space Wave. The values reported are just indicative.
Latest EZNEC version 5.0 does not contain true ground wave analysis either.
The professional EZNEC Pro/2 application is required to perform accurate ground wave analysis.
However, the $500 US price is prohibitive for personal use. However, as this antenna system
displayed some bizarre characteristics, the file was forwarded to and analyzed by Roy Lewallen
personally, using his professional NEC 4 software, to confirm these results. His AZ plot shows an
even deeper null to the south.
Nevertheless, calculations have been done to estimate the strength of the Horizontal field for both
the Ex and Ey directions and the Vertical field Ez at the Surrey PREOC center. The results are as
follows,
Table 2.3.7-1
Proposed Vertical Far Field Plot at Surrey PREOC
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At 20 feet, the VP field Ez is the same as the Inverted VEE at ~ 42 V whereas the HP field Ex is
about 7.6 V or 15 dB weaker and Ey at about 3.3 V, about 22 dB less. The vertical field
decreases with height whereas the horizontal field increases with height.
2.3.8
Proposed NSEMO Vertical VEE
An article in September – October issue of “The Canadian Amateur” entitled “A Dipole to Vertical
15
Antenna Converter” attracted the author’s attention. The concept is to use the vertical
balanced feed line as a vertical radiator by connecting both conductors together to the output of
the ATU, and by grounding the cold side of the ATU to the roof per Figure 2.3.8-1.
Inverted VEE Antenna used as
a non-resonsant Top loaded Vertical
Ladder Line is the
Vertical Radiator
Ladder Line Feeder
~ 60 feet long
Tie both wires
ladder line together
ATU Typical SGC -230
ATU
Figure 2.3.8-1
Proposed Vertical VEE at NSEMO
An ATU such as the SGC -230 will be needed to deal with the feed point impedances.
A remote switching device (relay) is required to change the connectivity from a ladder line feed to
a single conductor vertical radiator.
The Inverted VEE was investigated using this concept. The two conductors of the ladder line
feeder were modeled as a single vertical radiating conductor. The VEE portion is viewed as a
form of top loading.
S
W
Figure 2.3.8-2
Proposed Vertical VEE at NSEMO
15
“The Canadian Amateur”. September & October, 2009. David Wilson, VE3BBN
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As can be seen, the Vertical VEE has considerable asymmetry in the radiation patterns due to the
roof currents, but is somewhat improved.
Far field low angle field strengths are calculated and the results are given in Table 2.3.8-1
Table 2.3.8-1
Proposed Vertical VEE Far Field Plot at Surrey PREOC
At 20 feet, the VP field Ez is slightly higher at ~ 52 V (2 dB) compared to the Inverted VEE
whereas the HP Ex is about 8.7 V or 16 dB weaker; Ey is about 5 V, about 20 dB less.
2.3.9
Comparative Signal Strength
To convert field strength to antenna terminal voltage, a conversion factor is required. This is
referred to as the Antenna Factor (AF). Refer to Appendix VII for computing Antenna Factor.
The field strengths received at Surrey from the various antennas at NSEMO are tabulated as
antenna voltages. These voltages are then related to “S” meter reading as would be registered
on the receiver. This is compared to the noise floor for the particular band to determine if the
signal to noise ratio is positive or negative. Anything less than 6 dB S/N is considered rough copy
for SSB but would be acceptable for PSK.
These calculations refer to 80 m only. Field strength is in V/m
Antenna
Inverted VEE
Quarter Wave Vertical
Vertical VEE
Ex
5.8
7.6
8.7
Ey
6.0
3.3
5.1
Ez
42
42
52
Etotal
43.0
42.7
52.6
Table 2.3.9-1
Calculated Field Strengths for three Antennas at Surrey PREOC
Clearly, the vertically polarized Ez field is by far the strongest, typically 15 to 18 db. This is due to
the greater attenuation of the horizontally polarized field over that distance.
There is therefore an argument that a vertical antenna be used at the receiving station, in this
case Surrey PREOC. A horizontally polarized antenna would be disadvantaged by up to 18 B or
about 2-3 “S” points.
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HF PROPAGATION STUDY
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EZNEC computes field strength. That is NOT the same as the voltage presented at the antenna
feed point. Neglecting feed line losses, receiver input = antenna terminal voltage.
To determine the antenna terminal voltage, only Ez is converted from the field strength voltage by
using the Antenna Factor.
The Antenna column is the Transmit (Tx) antenna; the AF is applied to the Receive (Rx) antenna,
being a vertical in all cases.
The Antenna Terminal voltage V = Ez/ AF. The AF is derived in Appendix VII.
Units in Table 2.3.9-2 are as follows,
Ez = vertically polarized field strength in V/m (micro volts per meter)
V = antenna Voltage in uVolts (micro Volts) for a vertical antenna
S = S meter reading per value of V, where S9 = 50 V
N = Noise level in V from Appendix VII
S/N = Signal to Noise ratio in dB
Antenna, Tx
Inverted VEE
Quarter Wave Vertical
Vertical VEE
Ez
42.3
42.0
51.9
AF (Rx Ant)
0.0368
0.0368
0.0368
V (v)
1149
1141
1418
N (v)
67.9
67.9
67.9
S/N (dB)
24.6
24.5
26.4
S units
S9 + 27 dB
S9 + 27 dB
S9 + 27 dB
Table 2.3.9-2
NSEMO Antenna to Vertical Antenna at Surrey PREOC
Compare the vertically polarized signal/noise levels with the same Tx antennas to a horizontally
polarized dipole at the Rx location.
Antenna, Tx
Inverted VEE
Quarter Wave Vertical
Vertical VEE
•
Ex or Ey *
6.04
7.7
8.7
AF (Rx Ant)
0.094
0.094
0.094
V (v)
64.2
81.9
92.5
N (v)
26.5
26.5
26.5
S/N (dB)
7.6
9.8
10.8
S units
S9 + 2 dB
S9 + 2 dB
S9 + 4 dB
whichever is greatest
Table 2.3.9-3
NSEMO Antennas to Dipole Antenna at Surrey PREOC
There is a > 20 dB difference between antennas transmitting vertically polarized fields being
received on a horizontally polarized antenna as compared to vertical to vertical. This indicates
that PREOC’s and EOC’s might ALL want to install vertical antennas in order to communicate
locally by ground wave when NVIS fails.
This exercise is repeated for other locations on Vancouver Island, Appendix VIII.
2.3.10 Comments
Clearly, there is an advantage to using,
1.
2.
3.
4.
Vertically Polarized field component.
Inverted VEE to inverted VEE.
Vertical to Vertical.
Vertical VEE to Vertical (no one else has a Vertical VEE).
Using antennas that are cross polarized will result in unacceptable losses.
09-Mar-10
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2.4
Provincial Regional Emergency Operation Centers
2.4.1
Location of PREOC’s by Map
The PREOC locations are based on the street addresses reported from EmCom data,
www.ve7ed.com/documents/59.html
Google Earth is used to locate the PREOC using the street address by using the “Fly To“ utility.
Using the Google Earth hybrid view, the http://f6fvy.free.fr/qthLocator Grid Square locator offered
by Laurent Hass F6FVY is used to determine the Latitude, Longitude, and Grid Square. The view
offered is printed for each PREOC. The locations may not be exact but are close enough for this
work.
This map shows the general location of the PREOC’s
VE7NWZ
pgz
VE7PGZ
pgz
VE7KAZ
pgz
VE7NSR
NSEMO EOC
VE7NEZ
pgz
VE7SWF
pgz
VE7PEP
pgz
Figure 2.4.1-1
Mapped Locations of PREOC’s
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HF PROPAGATION STUDY
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2.4.2
Detailed PREOC Location Data
PREOC
Region
Call
North Vancouver
Kamloops
Nelson
Prince George
Saanich
Surrey
Terrace
NSEMO EOC
Central
South East
North East
Island
South West
North West
VE7NSR
VE7KAZ
VE7NEZ
VE7PGZ
VE7PEP
VE7SWF
VE7NWZ
Distance
from NSR
Bearing
degrees
km
degrees
123.1
120.4
117.3
122.8
123.4
122.8
128.6
Reference
234
418
510
84
24
689
0
48
85
2
197
124
329
Lat
Long
degrees
49.3
50.7
49.5
53.9
48.6
49.2
54.5
Table 2.4.2-1
PREOC Latitudes & Longitudes
Since this report is concerned with HF propagation between EOC’s, VE7NSR is taken as a
reference point and propagation is examined to all other sites.
Distances from VE7NSR to each PREOC, as well as bearings from VE7NSR, are calculated
using W6EL, version 2.70, propagation software, found at
http://www.qsl.net/w6elprop/
2.4.3
Equipment Profile by PREOC
Each PREOC has submitted equipment data, per the author’s request, so as to characterize the
HF capability of each PREOC on a comparable basis.
The survey is not exhaustive in equipment detail and such items as computers have not been
listed as they were not relevant to this work. However, HF Modems are, and so it can be
assumed that computers are used extensively, and indications are that that is so.
While taking the time to gather HF data, it also provided an opportunity to gather VHF/UHF data
as well and while included, it is not used in this study.
As the author is not aware of any other repository of such information, perhaps PREOC members
will find it useful to have an understanding of the capability of the other PREOC’s.
The data is organized with a cover sheet for each PREOC plus their summarized information.
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
CENTRAL REGION
KAMLOOPS PREOC – VE7KAZ
1255 – D Dalhousie Drive
Kamloops, B.C.
V2C 5Z5
Tel (250) 371-5240
Technical contact for this report:
Brady Conroy, VE7TAX, email Brady.Conroy@domtar.com
Alternately conroy@telus.net
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VE7KAZ KAMLOOPS HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Kenwood TS-480
no
100
SSB & Airmail
Station Designation
VE7KAZ Voice & Data
Modes
Modem
make/model
RMS PACTOR
Backup Power
Yes
HORIZONTAL ANTENNAS
Description
G5RV
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
HF
unknown
80/40/20/15/10 ?
~ 60'
internal to TS480
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
Force 12 Sigma 80
Force 12 Sigma 40
Elevated ~ 15'
Elevated ~ 15'
80
40
None required
None required
VERTICAL ANTENNAS
Description
Vertical dipole - center fed
Vertical dipole - center fed
HF NET Frequencies Commonly Used for EOC purposes
NET
PEP
BC Public Service Net
PEP
WINLINK
09-Mar-10
FREQUENCY
3735 kHz
3729 kHz
7060 KHz
3615 kHz
MODE
SSB
SSB
SSB
Air Mail
WINLINK Address
VE7KAZ@winlink.org
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VE7KAZ KAMLOOPS VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
VE7KEG
VE7KAZ
VE7KAM
VE7RXD
VE7TPK
VE7CHW - 10
147.180 +
146.52
145.01
145.05
144.47
144.97
FM Voice
FM Voice
6.2 Packet
6.2 Packet
6.2 Packet
RMS Packet
no
no
Kantronic 3
Kantronic 3
Kantronic 3
TNC
Data Rate
Rig
Antennas
9600
9600
9600
9600
Icom
Icom
TADM8
TADM8
TADM8
TADM8
LA 150
Vertical
Sincalir 4B
Vertical
Vertical
Vertical
Service
PREOC Contact
Simplex channel
CHAN 1
CHAN 2
CHAN 3 PREOC chanmel
Packet 6.2
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
Location
VE7RKA
146.960 -
FM Voice
Kamloops
Coverage
Local
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
Frequency
Modes
Location
VE7RLO
147.320 +
FM Voice
Mount Lolo
Network
Local & Wide area
Terminology RMS = Radio Message Station
CMS = Common Message Station
6.2 Packet = 2 meter packet capable of jpg. & txt file transmission
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VE7KAZ PREOC Site
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
SOUTH EAST REGION
NELSON PREOC – VE7NEZ
403 Vernon Street
Nelson, B.C.
V1L 4E6
Tel (250) 345-5904
Technical contact for this report:
Joe Rieberger, VE7CRJ, email jrieberger@cintek.com
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B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7NEZ NELSON HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Kenwood TS-480
none
100
SSB, Air Mail
Station Designation
VE7NEZ - HF
Modes
Modem
make/model
Pactor III
Backup Power
Generator
HORIZONTAL ANTENNAS
Description
Long Wire - 18M
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
HF
Self made
160M to 10M
20M
SGC SG-230
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
VERTICAL ANTENNAS
Description
None
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
PEP
WINLINK
3735 kHz
80 & 40M
SSB
Airmail
WINLINK Address
VE7NEZ@winlink.org
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B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7NEZ NELSON VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
Data Rate
Rig
Antennas
VE7NEZ - VHF/UHF
VHF - 50W
UHF - 35W
FM
FM
None
None
x
x
Yaesu FT-8800
Diamond Dual Band
Model X50
Old Forestry Antenna
150 - 174 MHz
Service
Local FM Voice
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Trail
Nelson
Frequency
146.84/146.24
146.64/146.04
Modes
FM
FM
Location
Red mountain
Slocan Ridge
Coverage
Trail,Castlegar and highway to Salmo
Nelson,Castlegar and highway to Nakusp
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
Nelson
09-Mar-10
Frequency
146.64/146.04
Modes
FM
Location
Slocan Ridge
57
Network
Tied to SIRG Network
Coverage to Okanagan and the coast
VA7JW
HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
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VANCOUVER NORTH SHORE
NORTH VANCOUVER EOC – VE7NSR
147 East 14th Street
North Vancouver, B.C.
V7L 2N4
Tel (604) 983-7440
Resources:
Technical contact for this report (the author) :
John White, VA7JW, email va7jw@shaw.ca
North Shore Amateur Radio Club www.nsarc.ca
North Shore Emergency Management Office http://www.nsemo.org/
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VE7NSR NORTH VANCOUVER HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Icom 756 pro3
Icom 718
SGC-2000
Icom 2 KL
no
no
100/ 400
100
100
SSB, RTTY, PSK
SSB, RTTY, PSK
SSB, Air Mail
Description
Station
Manufacturer
Bands
Height
Tuner
Notes 1 and 2
ant assigned to
make / model
meters
feet above ground
make / model
3 element Yagi
Inverted VEE
N4PC Horizontal Loop
HF-1
GOTA
SGC
SteppIR
self made
self made
20/17/15/12/10
160/80/40/20/17/15/12/10
160/80/40/20/17/15/12/10
~ 70
~ 110
~ 70
no
SGC 200
SGC 200
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
description
GAP Titan
elevated - roof
80/40/20/15/10
no radials required
Station Designation
VE7NSR - HF-1
VE7NSR - GOTA
VE7NSR - WIN-LINK
Modes
Modem
Backup Power
make/model
no
no
Pactor III
UPS / Generator
UPS / Generator
UPS / Generator
HORIZONTAL ANTENNAS
VERTICAL ANTENNAS
Description
Muiltband Vertical, not installed
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
BCPSN
PEP
PEP
WINLINK
3729 kHz
3735 kHz
7060 kHz
3615 kHz
SSB
SSB
SSB
Air Mail
WINLINK Address
VE7NSR@winlink.org
Notes: 1. Any HF antenna can be patched to any HF rig.
2. Antennas are defaulted to stations indicated
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VE7NSR NORTH VANCOUVER VHF/ UHF EQUIPMENT PROFILE
RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
Data Rate
Rig
VHF/UHF-VE7NSR
VHF/UHF-VE7NSR
VHF - VE7EMR
VHF - VE7NSR
UHF - VE7NSR
UHF - VE7NSR
6m 2m 70 cm
2m 70 cm
145.01
144.39
443.425
440.775+
SSB, FM Voice
FM
Packet
Packet
Packet
Packet
no
no
KPC-3
KPC-3
KPC-3
KPC-9612
x
x
1200
1200
1200
9600
Icom - 7000
Kenwood
Mota GM-300
Mota GM-300
Mota GM -300
MCX-100
Antennas
Service
rotatable yagi's General SSB
2 band vert General FM
Grab and Go kit
APRS (note 2)
TPARC (note 3)
VPAO (note 1)
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
VHF - VE7NSR +
UHF - VE7RNV
147.26
444.95
FM Voice
FM Voice
Location
Mount Seymour
Mount Fromme
Coverage
Lower mainland
IRLP node 1015 lower mainland
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
Frequency
Modes
Location
VE7RVA
VE7DJA
146.610-/t110.9
145.430 - / t141.3
FM
FM
Abbostford
Naniamo
Network
Southern Interior FVARESS
Island Trunk. NARA
NOTES: 1. VAPO = Vancouver Area Packet Association
2. APRS = Automatic Packet Reporting System
3. TPARC = Telephone Pioneers Amateur Radio club
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VE7NSR HF Operating Positions
09-Mar-10
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B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
NORTH EAST REGION
PRINCE GEORGE PREOC – VE7PGZ
3235 Westwood Drive
Prince George, B.C.
V2N 1S4
Tel (250) 612-4127
Resources
Technical contact for this report:
Frank VanderZande, VE7AV, email frankvdz@telus.net
North East – North West Regional Amateur Radio Communication Plan,
http://www.pgarc.org/emergency/NBCPlan.pdf
Prince George Amateur Radio Club, http://www.pgarc.org/
Information and Links, http://www.ve7av.ca/
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VE7PGZ PRINCE GEORGE HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Station Designation
VE7PGZ-1
VE7PGZ-2
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Modes
TS-480
FT-747GX
no
no
100W
100W
SSB
SSB
Modem
make/model
Pactor
no
Backup Power
Generator
Generator
HORIZONTAL ANTENNAS
Description
1 element rotatable dipole
2 element rotatable yagi
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
VE7PGZ-1 & -2
VE7PGZ-1 & -2
not specified
not specified
80 m
40 m
72 ft
72 ft
no
no
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
VERTICAL ANTENNAS
Description
None
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
BCPSN
PEP
PEP
Winlink
3792 kHz
3735 kHz
7060 kHz
3613.5 kHz
SSB
SSB
SSB
Airmail
WINLINK Address
VE7PGZ@winlink.org
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VE7PGZ PRINCE GEORGE VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
Data Rate
Rig
Antennas
VE7NWZ
VE7NWZ
VE7NWZ
VE7NWZ
VHF
VHF
VHF
VHF
FM
FM
FM
FM
No
No
No
No
n/a
n/a
n/a
n/a
TM-D700
TAD M8
IC-2000
IC-20
?
?
?
?
Service
Hand Held
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
VE7FPG
VE7RES
146.94 / 146.34
145.43 / 144.83
FM
FM
Location
Pilot Moutain
Tabor Moutain
Coverage
P George area +
P George area +
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
Frequency
Modes
Location
Network
Various
VHF / UHF
Many
Many
Extensive
For detail, please visit http://www.ve7av.ca
Links > Amateur Repeater Frequencies, cetnral and Northern BC and Prince George Amateur Radio Club
09-Mar-10
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09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VANCOUVER ISLAND REGION
SAANICH PREOC - VE7PEP
2261 Keating Cross Road
Saanichton, B.C.
V8M 2A5
Tel (250) 952-5848
Resources:
Technical contact for this report:
Kevin Hartley, VE7OVY / VA7FE, email ve7ovy@telus.net
BC Provincial Emergency Program http://www.pep.bc.ca/index.html
Provincial Emergency Radio Communications Service http://www.percs.bc.ca/
EmComm BC Section http://bc.emergencyradio.ca/
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VE7PEP SAANICH HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Kenwood TS480
Kenwood TS480
Yaesu FT-857
no
no
no
100
100
100
SSB 40/80m
Airmail
SSB 20/15/10/6m
no
PTC-II PRO
PTC-II EX
yes
yes
yes
Kenwood TS480
no
100
Airmail
PTC-II PRO
yes
Station Designation
VE7PEP - Voice
VE7PEP - WINLINK
VE7PEP
VE7VIS (not in service at
present -future)
Modes
Modem
make/model
Backup Power
HORIZONTAL ANTENNAS
Description
80/40 dipole
80/40 dipole
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
Winlink
Voice
Alpha Delta
Alpha Delta
1/2
1/2
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
Butternut
HF9V rooftop (10m)
80/40/30/20/15/10/6
rooftop ground system
Butternut
HF9V rooftop (10m)
80/40/30/20/15/10/6
rooftop ground system
10-20m (sloper) internal to TS480
10-20m (sloper) internal to TS480
VERTICAL ANTENNAS
Description
Multiband Vertical (Yaesu FT-857)
Multiband Vertical (Kenwood TS480
VE7VIS Winlink not in service yet)
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
BCPSN
PEP
PEP
WinLink
3729 kHz
3735 kHz
7060 kHz
3613.5 kHz
SSB
SSB
SSB
Airmail
WINLINK Address
VE7PEP@Winlink.org
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VE7PEP SAANICH VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
VE7PEP
VE7PEP
VE7PEP
VE7PEP
VE7PEP
Frequency
Modes
VHF/UHF/23
cm
VHF
UHF
VHF
UHF
FM Voice &
DSTAR
Packet
Packet
Voice
Voice
Modem
Data Rate
Rig
Antennas
no
~90k
Icom ID-1
triband vertical
KPC9612
KPC9612
no
no
1k2/9.6
1k2/9.6
-
Motorola CDM1550LS
Motorola CDM1550LS
Motorola CDM1550LS
Motorola CDM1550LS
dual band vert
dual band vert
dual band vert
dual band vert
Service
D Star Repeater & FM
Voice
Airmail
Airmail
Voice
Voice
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
Location
Coverage
Location
Network
per attached matrix
LINKED REPEATERS accessed for Emergency Operations.
Repeater
Frequency
Modes
per attached matrix
09-Mar-10
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B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
SOUTH WEST REGION
SURREY PREOC - VE7SWF
14275 – 96 Ave
Surrey, B.C.
V3V 7Z2
Tel (604) 586-4390
Technical contact for this report:
James Longley, VE7JMS email ve7jms@gmail.com
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7SWF SURREY HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Kenwood TS-480
Kenwood TS-480
Kenwood TS-480
no
no
no
100
100
100
SSB + CW
?
Airmail
Station Designation
VE7SWF - Radio 3735
VE7SWF - Radio 7060
VE7SWF - Radio 3615
Modes
Modem
make/model
Backup Power
no
?
?
?
PACTOR III
HORIZONTAL ANTENNAS
Description
Rotatable Dipole
Mutliband Rotable yagi
Dipole ?
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
3735
7060
3615
Optibeam OB1-80
Optibeam OB12-6
self made ?
80m
40/20/17/15/12/10
?
?
?
?
?
?
?
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
VERTICAL ANTENNAS
Description
do you have any verticals?
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
BCPSN
PEP
PEP
WINLINK
3729 kHz
3735 kHz
7060 kHz
3615 kHz
SSB
SSB
SSB
Air mail
WINLINK Address
72
VA7JW
HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7SWF SURREY VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
Data Rate
Rig
Antennas
Service
DATA NOT AVAILABLE
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
Location
Coverage
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
09-Mar-10
Frequency
Modes
Location
73
Network
VA7JW
HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
NORTH WEST REGION PREOC
TERRACE – VE7NWZ
Suite 1B – 3215 Eby Street
Terrace, B.C.
V8G 2X8
Tel (250) 615-4800
Resources:
Technical contact for this report:
Glenn Grieve, VE7CNQ, email glenn_grieve@hotmail.com
Terrace Amateur Radio Club http://www.terraceamateurradio.net/
NOTE:
09-Mar-10
Terrace has invested in a Satellite Telephone in case all modes of terrestrial
communications fail.
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7NWZ TERRACE HF EQUIPMENT PROFILE
HF RADIOS & MODEMS
Rig
RF Amplifier
RF Power Out
make / model
make / model
rig / amp
Kenwood 570D
Kenwood 570D
Yaesu FT-747
no
no
no
100
100
100
CW SSB
Airmail
SSB
Station Designation
VE7NWZ HF Main
VE7NWZ HF Data
VE7NWZ Portable
Modes
Modem
make/model
no
Pactor III
no
Backup Power
UPS MGE1500
UPS RS1200
AC / battery pwr
HORIZONTAL ANTENNAS
Description
4 Band Yagi with 40M extension
N - S Dipole cut for 3735 kHz
Inverted VEE "no trap" E-W Dipole
Station
Manufacturer
Bands
Height
Tuner
ant assigned to
make / model
meters
feet above ground
make / model
HF Main
HF Main
HF Data
Cushcraft A3S
Home made
Alpha Delta
40 / 20 / 15/ 10
80
80 / 40/ 20 / 15 / 10
58
30
45
rig tuner
rig tuner
rig tuner
Manufacturer
Mounting
Bands
Radial System
make / model
ground or elevated
meters
radial configuration or not required
VERTICAL ANTENNAS
Description
None
HF NET Frequencies Commonly Used for EOC purposes
09-Mar-10
NET
FREQUENCY
MODE
BCPSN
PEP
PEP
Winlink
3729 kHz
3735 kHz
7060 kHz
3613.5 kHz
SSB
SSB
SSB
Airmail
WINLINK Address
VE7NWZ@Winlink.org
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
VE7NWZ TERRACE VHF/UHF EQUIPMENT PROFILE
VHF / UHF RADIOS & MODEMS
Station Designation
Frequency
Modes
Modem
Data Rate
Rig
Antennas
Service
VE7NWZ
VHF
Airmail
Rigblaster
Pro
use HF
Pactor Modem
Icom IC-8000
Cushcraft A148-3s
Vertical at 50'
Not operational
VHF
UHF
VHF
VHF
FRS
FM
FM
FM
FM
FM
Yaesu FT-7800
Sinclair SRL 217
Sinclair SRL 317
Local base
VE7NWZ
VE7NWZ
VE7NWZ
VE7NWZ
no
n/a
n/a
n/a
n/a
no
no
no
two Icom IC-V8
Mota MCX 100
Uniden
Handhelds
Portable
Handhelds
LOCAL REPEATERS accessed for Emergency Operations
Repeater
Frequency
Modes
Location
VE7RTK
VE7FFU
VE7RDD
VE7RDD
146.000 ?
146.800 +
146.940 +
444.975
FM
FM
FM
FM
Terrace
Terrace
Terrace
Terrace
Coverage
Main Local Repeater
Private
Private with CTSS; not used
Does not exist
LINKED REPEATERS accessed for Emergency Operations. Identify repeater Network(s) your local repeaters would access.
Repeater
Frequency
Modes
Location
Network
No linked repeaters
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
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09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
2.4.3
Geographic Data per W6EL
NORTH VANCOUVER
NSEMO is the reference station. Lat = 49.3 N, Long = 123.1 W. All other stations and
parameters are measured with respect to NSEMO.
KAMLOOPS
NELSON
PRINCE GEORGE
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
SAANICH
SURREY
TERRACE
09-Mar-10
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HF PROPAGATION STUDY
B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
APPENDIX INDEX
APPENDIX I
Reference Antennas
APPENDIX II
Glossary of Ionospheric Terminology
APPENDIX III
DX Atlas Software
APPENDIX IV
Ionospheric Variation with Time
APPENDIX V
W6EL Propagation Software
APPENDIX VI
Solar Indices
APPENDIX VII
Antenna Factor and Noise
APPENDIX VIII
EZNEC Field Strength Calculation
APPENDIX IX
80 m Vertical Dipole Analysis
APPENDIX X
VHF / UHF Provincial Repeater Systems
APPENDIX XI
Technical Archive
09-Mar-10
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B.C. PROVINCIAL REGIONAL EMERGENCY OPERATION CENTERS
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APPENDIX I
REFERENCE ANTENNAS
1.
80 m DIPOLE - 1/4 WAVE ABOVE GROUND = 65 feet
Broadside
0
0 degrees Az
Broadside Radiation
All Horizontal polarization
0
Broadside at 90 elevation
Uniform 360 degrees
09-Mar-10
45
0
0
Az
Equally polarized
0
Broadside at 60 elevation
slight Y axis compression
83
90 Az
Radiation off end of antenna
All Vertical polarization
0
Broadside at 30 elevation
Y axis compression
VA7JW
APPENDIX I
REFERENCE ANTENNAS
2.
80 m DIPOLE – 1/8 WAVE ABOVE GROUND = 32 feet
Broadside
0
0 Az
Broadside Radiation
All Horizontal polarization
0
Broadside at 90 elevation
Uniform 360 degrees
09-Mar-10
0
0
45 Az
Equally polarized
0
Broadside at 60 elevation
slight Y axis compression
84
90 AZ
Radiation off end of antenna
All Vertical polarization
0
Broadside at 30 elevation
Y axis compression
VA7JW
APPENDIX I
REFERENCE ANTENNAS
3. 80 m INVERTED VEE -
¼ WAVE ABOVE GROUND = 65 feet. Ends droop 30 degrees
Broadside
0
0 degrees Az
Broadside Radiation
All Horizontal polarization
0
Broadside at 90 elevation
Uniform 360 degrees
09-Mar-10
45
0
0
Az
Equally polarized
0
Broadside at 60 elevation
slight Y axis compression
85
90 Az
Radiation off end of antenna
All Vertical polarization
0
Broadside at 30 elevation
Y axis compression
VA7JW
APPENDIX I
REFERENCE ANTENNAS
4. 80 m INVERTED VEE - 1/8 WAVE ABOVE GROUND = 32 feet. ENDS -20 DEGREES
Broadside
0
0 Az
Broadside Radiation
All Horizontal polarization
0
Broadside at 90 elevation
Uniform 360 degrees
09-Mar-10
0
0
45 Az
Equally polarized
0
Broadside at 60 elevation
slight Y axis compression
86
90 AZ
Radiation off end of antenna
All Vertical polarization
0
Broadside at 30 elevation
Y axis compression
VA7JW
APPENDIX I
REFERENCE ANTENNAS
5.
80 m QUARTER WAVE VERTICAL with 4 RADIALS - GROUND LEVEL
Azimuth Plot
6.
Elevation Plot
80 m QUARTER WAVE VERTICAL with 4 RADIALS
1/2 WAVE LENGTH ABOVE GROUND = 65 Feet
There is very little higher lobe development at 1/8 wavelength above ground
09-Mar-10
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APPENDIX I
REFERENCE ANTENNAS
Azimuth Plot
Elevation Plot
7. 80 m QUARTER WAVE VERTICAL with 4 RADIALS
3/4 WAVE LENGTH ABOVE GROUND = 97 Feet
Azimuth Plot
09-Mar-10
Elevation Plot
88
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APPENDIX I
REFERENCE ANTENNAS
8. 80 m QUARTER WAVE VERTICAL with RADIALS
ONE WAVE LENGTH ABOVE GROUND = 129 Feet
Azimuth Plot
09-Mar-10
Elevation Plot
89
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APPENDIX I
REFERENCE ANTENNAS
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09-Mar-10
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APPENDIX II
GLOSSARY of SOLAR and IONOSPHERIC TERMS
Sources of information:
http://www.ukssdc.ac.uk/wdcc1/ionosondes/ursi_codes.html
http://spidr.ngdc.noaa.gov/spidr/help.do?group=Iono
1. SOLAR TERMS – Official Definitions
ap index
A 3-hourly "equivalent amplitude" of geomagnetic activity based on K index data. “p” means
planetary.
Ap index
The planetary index for measuring the strength of a disturbance in the earth's magnetic field,
defined over a period of one day from a set of standard geomagnetic observatories around the
world. It is determined from the eight daily “ap” indexes
K Index
A three hourly index of geomagnetic activity relative to an assumed quiet day curve for the
recording site. K index values range from 0 (very quiet) up to 9 (extremely disturbed).
kp index
A 3-hourly planetary geomagnetic index of activity generated in Gottingen, Germany, based on
the K index from 12 or 13 geomagnetic observatories distributed around the world. Kp indexes
are used to determine the ap indexes.
Solar Flux
1 solar flux unit = 10 ^ -22 Watts / per square meter / per Hz. Measured at 10.7 cm by the
Hertzberg Institute of Astrophysics N.R.C. of Canada at Penticton BC.
2. IONOSPHERIC TERMS – Official Definitions
foE
The critical frequency of the E layer. The maximum ordinary mode frequency which can be
reflected from this layer
foEs
The highest ordinary mode frequency which presents a mainly continuous sporadic E (Es) trace
is observed on an ionogram.
foF1
The critical frequency of the F1 layer. The maximum ordinary mode frequency capable of vertical
reflection from the F1 of the ionosphere
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APPENDIX II
GLOSSARY of SOLAR and IONOSPHERIC TERMS
foF2
The critical frequency of the F2 layer. The maximum ordinary mode frequency capable of vertical
reflection from the F2 of the ionosphere
Fmin
The lowest frequency refracted from the ionosphere and recorded in the ionogram. It gives
indirect information on the absorption occurring in the ionosphere
h'F
At night when the F2 and F1 layers merge to form the F layer, h’F is measured. Similar heights
are obtained for the E and F1 layers
h'F2
The minimum virtual height of the F2 layer.
hm
The height of the maximum electron density
hmF2
The height of maximum obtained by fitting a theoretical h'f curve for the parabola of best fit to the
observed ordinary wave trace near foF2 without correcting for underlying ionization
Middle latitudes
With specific reference to zones of geomagnetic activity, "middle latitudes" refers to 20 deg. to 50
deg. geomagnetic latitude
D
Skip distance (single hop) on surface of earth
M
The M factor is a conversion factor for obtaining the maximum frequency usable in a given
oblique propagation distance from the critical frequency at vertical incidence. M is the ratio of the
maximum usable frequency at a distance of 3000 km to the F2 layer critical frequency, foF2.
M(3000)F2
The M factor for the standard distance of 3000 km is called M(3000) which is usually expressed
with the name of refraction layers as M(3000)F2 or M(3000)F1
TEC
Total Electron Count usually measured as x 10^ 5 electrons / cubic cm
16
16
Davies Ionospheric Radio Propagation. National Bureau of Standards 1967 Ed. Section 3.3.3.2, Figure 3.14
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APPENDIX III
DX ATLAS
1. Overview
The DX Atlas Suite of software is among other things, a real time, solar index driven, propagation
reporting tool that provides worldwide information. The information is displayed on a world map
and is highly intuitive and easy to read. The software is offered by Alex Shovkoplyas, VE3NEA,
and is available for purchase and download at www.dxatlas.com
2. Ionoprobe ($20.00)
This software automatically retrieves the required real time solar indices and stores them for use
with DX Atlas and Ham Cap (Section 4 following). This application MUST be used with DX Atlas
to report ionospheric conditions in real time.
Figure 1
Ionoprobe Window
All data fields must be populated. They ought to update when Ionoprobe is loaded.
icon is clicked. It just removes itself from the screen
Ionoprobe does NOT close when the
and keeps running in the background. The Ionoprobe icon can be found in the application tray at
the bottom right of Windows. While Ionoprobe is resident, DX Atlas and HamCap pick up the
information.
To exit (turn off) Ionoprobe, go to the tray icon and click Exit.
If you open Ionoprobe from the Windows program menu or shortcut again, a second instance of
Ionoprobe will run leaving two icons in the tray. You might find you have 3 or 4 Ionoprobe’s
running at the same time f not careful, although it doesn’t seem to matter.
If the data does not update, right click the tray icon and choose “Download Latest Data”.
Normally the “Auto Download” option should be checked.
Clicking on the Weekly and Yearly tabs will provide graphs of Sunspot Number, Solar Flux, Ap
Index, Proton Flux and X ray Flux. You will have to drag the window bottom down to view all.
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APPENDIX III
DX ATLAS
3. DX Atlas ($30.00)
This is the “main” presentation of the DX Atlas suite. This image shows the globe in the
Azimuthal (great circle) presentation centered on Vancouver. The grey contours represent
ionization density world wide. Dark is low ionization, light is highest.
Three world map displays are offered. Shown here is the Azimuthal (Great Circle) presentation
centered on Vancouver.
Open Ionoprobe first, ensure that the data updates, and then close the Ionoprobe window. Then
open DX Atlas and ensure that the Indices field at the bottom of the screen is GREEN. This
indicates that Ionoprobe has loaded DX Atlas with the current solar data and is “Live”.
By clicking on the ionospheric
icon, one can bring up a number of different ionospheric
data reports, Click on the desired parameter in the drop down menu. The ones we are interested
in are the critical frequency foF2, and the height of the F layer, hmF2. Note that DX Atlas labels
this as HmF2.
Choose Map display
Ionospheric
Icon
Magnify
Image
Indices field
MUST be green
Figure 2
DX Atlas Window
Left click the map to Mouse over Vancouver and left click. This will center Vancouver in the
display. Right click to stick in a pin. This is the home QTH. Expand the display to maximum
using the + magnifying glass.
The ionospheric contours will be evident as shades of gray. These contours will change
depending on the menu item picked on the ionospheric Icon.
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APPENDIX III
DX ATLAS
Mouse over VE7
or anywhere else
Figure 3
Display of foF2
Read foF2 or
HmF2 in the tray
Having chosen “F2 Layer Critical Frequency” from the drop down menu, mouse over VE7 and
read the value of foF2 in the bottom tray. foF2 will vary as the mouse is moved about. Similarly
select from the drop down menu “F2 Layer height”
4. HamCap (Free)
This application presents a small window that provides, at a glance, information regarding
possible path openings to anywhere in the world over a 24 hour period. The yellow rectangle
indicates best time / likelihood for each band. More of a DX’ing tool than for EmCom.
Figure 4
HamCap Window
09-Mar-10
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APPENDIX III
DX ATLAS
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09-Mar-10
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APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
GRAPH TIMES are UTC
UTC
PST
0.00
4:00 pm
3:00
7 pm
6:00
10 pm
9:00
1 am
12:00
4 am
15:00
7 am
18:00
10 am
21:00
1 pm
Figure 1
foF2 Critical Frequency Variation
Data - Hourly by the Month - Sept 2008 to October 2009
Figure 2
hmF2 Layer Height Variation
Data - Hourly by the Month - Sept 2008 to October 2009
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APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
UTC
PST
0.00
4:00 pm
3:00
7 pm
6:00
10 pm
9:00
1 am
12:00
4 am
15:00
7 am
18:00
10 am
21:00
1 pm
Solar Max
Solar Min
Figure 3
foF2 Critical Frequency Variation at Solstice and Equinox
Data - Hourly by the Year - Feb 2001 to October 2009
Solar Min
Solar Max
Figure 4
hmF2 Ionospheric Height at Solstice & Equinox
Data - Hourly by the Year – Feb 2001 to October 2009
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APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
UTC
PST
0.00
4:00 pm
3:00
7 pm
6:00
10 pm
9:00
1 am
12:00
4 am
15:00
7 am
18:00
10 am
21:00
1 pm
Figure 5
fmin Absorptive Frequency Variation
Data - Monthly by the Hour - Sept 2008 to October 2009
Figure 6
foF2 Critical Frequency Variation
Data – Daily by the Hour - Sept 2008 to October 2009
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APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
NOTES:
Figure 1 – Critical frequency is higher in the summer due to increased intensity of ionizing
radiation improving the ability of the ionosphere to refract higher frequency signals. It is also
higher in the middle of the day and lower in the middle of the night.
Figure 2 - F2 layer height is lower in the summer as the ionizing radiation, being more intense,
penetrates the atmosphere to a lower level.
Figure 3 - F2 Critical frequency is higher at solar maximum due to increased intensity of ionizing
radiation.
Figure 4 – F2 layer height is lower at solar maximum as the ionizing radiation, being more
intense, penetrates the atmosphere to a lower level.
Figure 5 – Absorptive frequency fmin is higher in summer as the ionizing radiation, being more
intense, increases the ionization density in the ionosphere thus attenuating the signals and
raising the lowest useable frequency to a higher value, i.e. 160 m will be mostly unusable in the
daytime, Spring, Summer, & Fall months.
Figure 6 - F2 Critical frequency rises in the daylight hours and falls in the darkness hours.
Visit these graphs at www.nsrac.ca/ > Tech Archive > HF_PREOC_Study > Ionographs
Go to file: GetMUFData_V14_User.xls for Detailed MUF Calculator, foF2 Daily & Monthly
Click on the drop down menu buttons to choose Month and Time
Go to file: foF2_hmF2_ByYear_V14_User.xls for foF2 and hmF2 yearly
Similarly click drop down menus for Month and Time
Besides the MUF term, there are other terms used to describe the probability of path availability.
These are the most common,
LUF
Lowest Useable Frequency is the lowest effective frequency that can be used 90% of the
days of the month. LUF is limited to absorption.
FOT
Frequency of Optimum Transmission is the highest effective (i.e. working) frequency that
is predicted to be usable for a specified path and time for 90% of the days of the month.
Sometimes called Optimum Working Frequency (OWF), it is defined as 85% of the MUF.
MUF Maximum Useable Frequency is the highest frequency applicable to 50% of the days of a
month.
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APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
This detailed MUF Calculator provides more information than the simple MUF calculator in that a range of MUFs is given; Minimum likely, Average
and Maximum likely, based on ionospheric observatory reports over the last year. This will of course change through the solar cycle.
Where the MUF is less than the operating frequency. The cell appears pink.
foF2 and hmF2 are entered based on the latest DX Atlas prediction. hmF2 can be left at 242 km as an average value as it does not change
significantly. However, foF2 changes significantly over short periods of time (hours) and is required to be up-to-date.
Follow instructions on sheet for use. Go to www.nsarc.ca > Tech Archive > Ionographs > GetMUFData_V14_User.xls
Note that at this time, the calculator only works between NSEMO to other PREOC’s, for the purposes of this study, and not PREOC to PREOC. If
there is demand for this the table to be any PREOC to any other PREOC, the calculator can be revised.
Determine MUF between VE7NSR and
VE7KAZ
Change this callsign for MUF Calc
Yellow fields are data entry. Green fields are computed values
Enter Distance between Stations
Note 3
234
Maximum Useable Frequency between VE7NSR
16:00
17:00
0:00
Mth
1
2
3
4
5
6
7
8
9
10
11
12
Min
3.941
3.949
3.956
3.949
3.972
4.030
4.137
4.060
3.952
3.933
3.922
3.944
Ave
3.821
3.832
3.843
3.876
3.884
3.874
3.895
3.875
3.837
3.860
3.797
3.814
Determine Take Off Angle
Take Off Angle
Note 1 Enter Critical Frequency foF2
kilometers
and
Enter Net Frequency
Max
3.821
3.832
3.843
3.876
3.884
3.874
3.895
3.875
3.837
3.860
3.797
3.814
3.868
3.859
3.875
3.901
3.905
3.901
3.943
4.000
3.869
3.829
3.874
3.906
Ave
3.700
3.751
3.777
3.815
3.809
3.806
3.831
3.794
3.765
3.760
3.773
3.758
22:00
23:00
6:00
3.700
3.751
3.777
3.815
3.809
3.806
3.831
3.794
3.765
3.760
3.773
3.758
FormulaTan = h'F / (D/2)
64.7
Take-off angle has a lot to do with choice of antennas
Min
3.855
3.898
3.882
3.807
3.880
3.881
3.890
4.001
3.900
3.917
3.910
3.896
MHz
Note 2 The average layer Height for hmF2
3.735 MHz
Note 4
Data Entry
248
kilometers
Formulas DO NOT ENTER
Kamloops
VE7KAZ
19:00
20:00
3:00
3.5
Ave
3.708
3.742
3.722
3.754
3.761
3.778
3.805
3.763
3.740
3.734
3.729
3.767
1:00
2:00
9:00
Max
3.708
3.742
3.722
3.754
3.761
3.778
3.805
3.763
3.740
3.734
3.729
3.767
Min
3.958
3.897
3.937
3.906
3.857
3.922
3.889
3.836
3.939
3.928
3.957
3.897
4:00
5:00
12:00
Ave
3.734
3.685
3.710
3.707
3.751
3.771
3.750
3.732
3.735
3.689
3.732
3.773
Max
3.734
3.685
3.710
3.707
3.751
3.771
3.750
3.732
3.735
3.689
3.732
3.773
Min
4.012
3.894
3.916
3.935
3.990
3.987
4.069
4.059
3.985
4.025
4.038
3.897
Ave
3.769
3.705
3.746
3.814
3.853
3.859
3.809
3.818
3.770
3.722
3.751
3.786
7:00
8:00
15:00
Max
3.769
3.705
3.746
3.814
3.853
3.859
3.809
3.818
3.770
3.722
3.751
3.786
Min
4.034
3.992
4.033
4.180
4.189
4.265
4.241
4.259
4.156
4.139
3.962
3.997
Ave
3.804
3.818
3.898
3.942
3.926
3.906
3.857
3.900
3.880
3.806
3.813
3.816
10:00
11:00
18:00
Max
3.804
3.818
3.898
3.942
3.926
3.906
3.857
3.900
3.880
3.806
3.813
3.816
Min
4.008
4.004
4.047
4.299
4.345
4.348
4.358
4.307
4.175
4.115
4.016
3.994
Ave
3.909
3.906
3.900
3.922
3.927
3.960
3.913
3.947
3.926
3.899
3.885
3.886
13:00
14:00
21:00
Max
3.909
3.906
3.900
3.922
3.927
3.960
3.913
3.947
3.926
3.899
3.885
3.886
Min
4.018
4.008
4.011
4.187
4.259
4.261
4.255
4.287
4.154
4.009
4.054
4.017
Ave
3.946
3.928
3.921
3.939
3.900
3.927
4.017
3.943
3.902
3.856
3.906
3.934
PST
PDT
UTC
Max
3.946
3.928
3.921
3.939
3.900
3.927
4.017
3.943
3.902
3.856
3.906
3.934
Note 1 foF2 MUST be current for this calculation. Use DX Atlas for latest value
foF2 will cahnge hourly
Note 2 hmF2 should be latest value per DX Atlas although 248 kk can be used as default.
This value will change with Solar Cycle
Note 3 Entering PREOC callsign automatically enters distance from NSEMO to that PREOC
Figure 7
Detailed MUF Calculator
09-Mar-10
101
VA7JW
APPENDIX IV
IONOSPHERIC VARIATION WITH TIME
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09-Mar-10
102
VA7JW
APPENDIX V
W6EL PROPAGATION SOFTWARE
1. Setup Screen
Terminal A is defined as VE7SWF, Surrey PREOC by entering the Lat and Long.
Terminal B will be another PREOC, in this case Terrace, also defined by Lat. and Long.
Propagation data and predictions will be determined for this path.
Figure 1
Location Setup
2. Summarized Path Information
Between Surrey and Terrace locations. Note distance between stations, short path.
Figure 2
Geographic Path Data
3. Path Prediction
Prediction shows opening on 40 and 80 m. However the availability on 40m is < 25%
Availability on 80 m is predicted between 0000 and 04:00 hours and then falls off as the MUF
deteriorates.
09-Mar-10
103
VA7JW
APPENDIX V
W6EL PROPAGATION SOFTWARE
UTC 00:00 corresponds to 4 pm PST and 04:00 to 8 pm PST. The band “closes” by 06:30 UTC
or 10:30 pm. PST
Figure 3
Numerical Propagation Report
Figure 4
Graphical Propagation Report
Figure 5
Graphical MUF Report
09-Mar-10
104
VA7JW
APPENDIX VI
SOLAR INDICES
1. Overview
The ionosphere is a highly variable and active entity. It is subject to disturbances and variations
not minutely predicable or measurable that can greatly affect the path. This gives rise to a level
of uncertainty of path availability. As such, path availability is dealt with in a statistical context
and availability is often stated as a probability, i.e. 50% probability a path will be available on 80
m at a given time.
2. Solar Indices
The activity of the Sun is monitored continuously in terms that provide information on the level of
ionization in the ionosphere. This ionization density has everything to do with the ability of the
ionosphere to return signals to earth as per the values of hmF2 and foF2.
Three main parameters commonly referred to are the SFI, ap and K indices.
3. Solar Flux Index (SFI)
This is a measurement of the intensity of radiation from the Sun. Ultraviolet (UV) radiation
produces the ionization in the upper, rarified atmosphere. The ability of the ionosphere to return
signals is directly related to the ionization density. The UV is not measured directly but is inferred
(with high correlation) to radio frequency radiation measured at ~ 2400 MHz. This is done with a
special sun-tracking receiver at the Penticton Radio Observatory amongst other locations world
17
wide . The SFI is lowest when the Sun Spot cycle is at its minimum, typically SFI = 70. At
sunspot maximum, SFI will be upwards to 200 or more. HF propagation on the high bands is
much better at maximums than minimums. The low bands may find propagation somewhat
worse at maximums due to increased absorption. The SFI varies as per the 11 year Sun Spot
cycle.
There is another measure of Solar Flux referred to as Sun Spot Number (SSN). The SFI and
SSN are related and intended to predict the same level of intensity. The relationship is,
SFI = 73.4 + 0.63R
where R is the daily reported SSN
4. “ap” Index
This is a measure of the instability of earth’s magnetic field. Ideally it would be unchanging.
However, the electrons and protons leaving the surface of the Sun produce a “Solar Wind”. This
stream of charged particles travels outward in all directions at speeds of 200 to 1000 km/second.
The earth’s magnetic field intercepts these particles and captures some of them (Van Allen belts)
as well as redirecting others around the earth. Many particles “precipitate” downwards in the
Polar Regions following the earth’s magnetic lines of force. The particles are of sufficient energy
to further ionize the air and make it glow, hence the Auroras. The particles also flow around the
earth within the ionosphere and constitute very large currents (Electrojets) which in turn have
significant magnetic fields. These fields add or subtract to the earths magnetic field. These
variations are measurable and are monitored. Needless to say, large variable currents flowing in
the ionosphere will cause disturbances to the ionosphere that will cause propagation anomalies.
By measuring these dynamic changes, that is, the disturbances in the earth’s magnetic field, one
can INFER the disturbance in the ionosphere.
17
Intensity is measured in 10^ -22 watts / per square meter / per Hertz
09-Mar-10
105
VA7JW
APPENDIX VI
SOLAR INDICES
A value of “ap” =1 would represent very quiet, undisturbed field whereas “ap” = 50 would indicate
major disturbances and cause difficulties in ionospheric propagation.
“a” is measured world wide every 3 hours. The data is averaged from all observatories. The
published “ap” index is a running average of the last 8 averaged indices representing the last 24
hours. Every 3 hours a new “a” value is added and averaged in as the oldest value is dropped
off. This gives a 24 hour running report on the average world wide ionospheric disturbance.
5. “K” index
This is another indicator of the instability of the earth’s magnetic field. Using the same data, but
unlike the “a” which is averaged over a 24 hour period, “K” is reported every 3 hours and advises
us that change is taking place. This can indicate that propagation may be getting better or worse.
The “a” index follows but is slower to change as the updated 3 hour reports still include the last
seven of the 24 hour figures. K =0 is best, K = 10 is worst and would create impossible
communications situations.
6. Other
As if these variables are not enough, there are other disturbances which will upset or make
communications impossible. Because the Sun drives the entire HF propagation scenario, what
happens on the Sun is felt on earth in terms of ionospheric conditions.
There are Ionospheric Storms, Sudden Ionospheric Disturbances, and Polar Cap Blackouts, all of
which can cause propagation to fail completely within in minutes. These are typically caused by
unpredictable flares on the sun which emit intense X rays which over-ionize the ionosphere and
absorb all signals. Another event is the Coronal Mass Ejection (CME) whereby a portion of the
Sun’s surface is ejected into space as a result of an eruptive flare. This mass carries within it
energetic charged particles, and contains an internal magnetic field of it’s own. If this mass
intercepts earth, the ionosphere is seriously affected. These events can produce spectacular
auroras.
The QSL.Net website publishes indices of importance to our interests.
http://dx.qsl.net/propagation/propagation.html
Many other solar parameters are listed as well. A Gray line map, World wide MUF (3000 km
assumed skip), X Ray Flux, Sun images, Auroral Activity, Forecasts, and Solar Wind data.
09-Mar-10
106
VA7JW
APPENDIX VII
ANTENNA FACTOR & NOISE
1. MODEL
UNDESIRED
ATMOSPHERIC, GALACTIC
and MAN MADE NOISE
microvolts per meter
DESIRED RADIO SIGNAL
microvolts per meter
RESONANT DIPOLE ANTENNA
TERMINAL VOLTAGE AT ANTENNA
microvolts
TRANSMISSION
LINE
TERMINAL VOLTAGE AT RECEIVER
microvolts
MF / HF / VHF
RECEIVER
Figure 1
2. RECEIVER SENSITIVITY and NOISE FLOOR
Typical sensitivity of a modern HF receiver is generally less than ~ 0.2 V for 10 dB Signal to
Noise.
The receiver noise floor is the noise level generated by the receiver circuits. This level is in the
order of 0.07V for a modern HF receiver.
The noise floor of the receiver is much lower than the noise from external sources, and so
external noise governs what can be heard.
3. ANTENNA FACTOR
Antenna Factor (AF) allows for the conversion of signal field strength “E”, specified in Volts /
meter, to antenna terminal voltage, specified in Volts “V”
AF = E/V
The general formula is,
√
AF = E/V = (f/75) (30/ZoG)
18
where,
f = freq in MHz,
Zo = Receiver input Z = 50 ohm
G = antenna gain factor over isotropic (not in dB)
This can be reduced to a much simpler expression
AF = E/V = 0.0325 f / √ G
AF varies with frequency f and the gain of the antenna G. Gain is not expressed in dB but as a
factor with respect to an isotropic antenna. i.e. 2x
18
W.K. Roberts “ A Guide to FCC Equipment Authorizations, Second Edition/ The EMXX Corporation, 1985 ed. Page 106
09-Mar-10
107
VA7JW
APPENDIX VII
ANTENNA FACTOR & NOISE
For our study, only the half wave dipole or the quarter wave vertical is considered.
For a ½ wave dipole, the Gain factor G, is 1.64 (2.16 dB)
For a ¼ wave vertical, the Gain factor G, is 3.27 (5.14 dB)
For further information on AF, refer to,
http://en.wikipedia.org/wiki/Dipole_antenna
Band
160 m
160 m
80 m
80 m
40 m
40 m
Antenna
/2 Dipole
/4 Vertical
/2 Dipole
/4 Vertical
/2 Dipole
/4 Vertical
F MHz
1.9
1.9
3.7
3.7
7.1
7.1
Gain Factor
1.64
3.27
1.64
3.27
1.64
3.27
AF
0.0483
0.0189
0.0940
0.0368
0.180
0.0706
Table 1
The Antenna Terminal Voltage “V” is then calculated as,
V = E/AF
4. EXTERNAL NOISE SOURCES
According to Figure 2, noise external to the receiver in the range of 2 to 20 MHz, is derived from 2
main sources; Atmospheric and Man-Made.
For most users, Man-Made is the dominant source of noise across the HF band. However,
atmospheric will govern only 20 % of the time in a quiet rural location between 7 and 15 MHz
whereas for 50% of the time, atmospheric will be dominant across the band. Man-Made replaces
20% atmospheric below 7 MHz and above 15 MHz.
Figure 2
ITU-R PI.372-6 Man Made Noise Levels
2-20 MHz
Choosing the 160, 80, and 40 m bands from Figure 2, reading the field strength in dbV/m, which
is dB above 1 V/m, is per Table 3,
09-Mar-10
108
VA7JW
APPENDIX VII
ANTENNA FACTOR & NOISE
Condition
Residential, Man Made
Rural Man Made
Quiet Rural, Man Made
Atmospheric (50%)
Atmospheric (20%)
160 m
dBV/m
+9
+4
-10
-5
< -20
80 m
dBV/m
+8
+2
-12
-5
-20
40 m
dBV/m
+6
0
-14
-1
-15
Table 3
Noise Levels Residential = Urban Environment
5. ANTENNA TERMINAL NOISE LEVELS
The noise levels are given as field strength in dB above 1 V / meter
These have to be converted to V at the antenna terminal of the particular antenna being
examined.
For the 80 m band, in the Residential category which best describes the radio environment at
NSEMO in North Vancouver and for most of us in the urban environment,
Antenna
Inverted VEE
Quarter Wave Vertical
Vertical VEE
dBV/m
+8
+8
+8
V/m (E)
2.5
2.5
2.5
AF
0.094
0.0368
0.0368*
V
26.5
67.9
67.9
S units
S8
S9+ 3 dB
S9+ 3 dB
* used same AF as vertical as don’t know how to perform the calculation of AF for the vertical VEE
Table 4
Noise levels at Antenna Terminals
Note that the Vertical antenna is typically noisier than a horizontal dipole due to the larger AF
which, as well as favoring low angle (DX) signals, also favors low angle urban noise sources.
Radiated man made noise would have to be considered as randomly polarized, dependent on the
nature of the radiating equipment. The vertically polarized component will propagate more
successfully as ground wave than the horizontal component, and so urban noise is considered to
be mainly vertically polarized. This couples well into a vertical antenna.
Ground mounted Verticals with radial systems either buried in the ground or lie on the ground
(earth) will have induced antenna noise currents due to currents flowing in the ground. These
currents are typically sourced from man-made electrical systems. Consider that the entire 60
cycle electrical distribution system is earthed at every service entrance and that electrical
equipments generating noise are connected everywhere and provide a path for noise induced
earth currents. It is also shown that radials buried in the ground operate less efficiently than
19
radials raised a foot or so off the ground .
19
QST March 2010. “An Experimental Look as Ground Systems for HF Verticals”. Severns N6LF
09-Mar-10
109
VA7JW
APPENDIX VII
ANTENNA FACTOR & NOISE
6. S METER READINGS
Input levels in Volts will read accordingly for an “S” meter calibrated to read S9 with 50 V at the
receiver input.
S Meter
0
1
2
3
4
5
6
7
8
9
+10 dB
+20 dB
+30 dB
+40 dB
+50 dB
+60 dB
Volts
~ 0.1
~0.2
~0.4
~0.8
1.56
3.125
6.25
12.5
25
50
158
500
~ 1.6 mV
5 mV
~16 mV
50 mV
Table 5
Receiver Antenna Input Voltage to S Meter Conversion
09-Mar-10
110
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
Calculate the Receive Field Strength at Surrey
for the Inverted VEE Antenna Transmitting from NSEMO
1.
The antenna models are oriented in space with reference to a coordinate system based on a
true South – North “Y” axis and an West - East “X” axis with the origin pegged to the NE
corner of the NSEMO building.
2.
All other locations will use this “X” & “Y” reference system such that their location in space is
with respect to NSEMO as defined by the origin as set up at the NE corner of NSEMO.
3.
This system ensures that the antenna radiation patterns are correctly oriented with respect to
distant stations.
4.
The surface distance from NSEMO to Surrey is determined by Lat and Long each location
using the W6EL software to calculate distance “D” and bearing with respect to NSEMO per
Table 2.4.2-1 and Table 1 this Appendix.
5.
The North-South “X” distance and the East-West “Y” distances are resolved using
trigonometry as the hypotenuse is known (24 km) as well as the enclosed angle = (180 deg –
bearing)
NSEMO
EOC
X = West
EZNEC
Coordinate
System
Y = 8.3 mi
56o
D=
X = -12.4 mi
Y = South
15
mi
Surrey
PREOC
Figure 1
Resolving N-S and E-W (Y and X components respectively) Distances
6.
Open EZNEC to the antenna to be analyzed.
7.
Open Main Menu > Setups > Near Field
Choose E field and Cartesian coordinates. Enter X, Y and Z in FEET since the antenna
dimensions selected were feet. The Z component is height and is computed for ground
level = 0 up to 60 feet
Figure 2
EZNEC X and Y Distances
09-Mar-10
111
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
8.
Open Main Menu > Options > Power Level
Uncheck the Absolute field and enter 100 (watts) in the Power level field. All antennas
are compared at the 100W level.
Figure 3
Setting Power Level
9.
To calculate the field strength at this point in space (Surrey PREOC), click the NF tab in the
Main Control panel.
Figure 4
EZNEC Numerical Data
10. EZNEC provides the field strength values in numerical, tabular form. Each of the Horizontally
polarized fields Ex and Ey and the Vertically polarized field Ez are given for each 10 foot
increment specified from 0 to 60 feet
Table 1 lists various Vancouver Island locations as well as Surrey and the NSEMO reference
location.
Table 2.2.7-1 looks at the ground wave path for terrain and surface materials. Factors affecting
the success of propagation are primarily the distances and obstructions.
The field strengths at the Vancouver Island locations are calculated out of interest to see if the
Vertically Polarized field is of use from NSEMO to those Vancouver Island cities.
Field strength is measured at various Elevations. This is the Height of the Receiving Antenna,
above ground estimated at 50 feet, plus the Height of Ground at the Lat / Long location.
Vertical antenna efficiency has not been taken into account. Low band verticals, due to
foreshortened lengths and various multi-band traps if so equipped, are not as efficient as a half
wave wire dipole.
09-Mar-10
112
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
Location
EZNEC
sin
X
distance
cos
Y
distance
feet
Bearing
(bearing)
feet
(bearing)
Feet
0
0
0
0
0
0
0
24
14.9
78693
-56
-0.8290
-65,240
0.5592
44,005
269
96
59.6
314,772
89
0.9998
314,725
0.0175
5,494
148
259
69
42.8
226,243
79
0.9816
222,086
0.1908
43,169
112
162
236
64
39.7
209,848
56
0.8290
173,972
0.5592
117,346
30
98
148
225
65
40.4
213,127
45
0.7071
150,704
0.7071
150,704
123.7
16
52
102
219
74
46.0
242,637
39
0.6293
152,696
0.7771
188,564
48.6
123.4
63
207
257
197
84
52.2
275,426
17
0.2924
80,535
0.9563
263,391
48.4
123.3
30
98
148
189
104
64.6
341,004
9
0.1564
53,345
0.9877
336,805
Lat
Long
Elevation
Bearing
Distance (W6EL)
degrees
degrees
m
feet
Ant
degrees
km
mi
NSEMO
49.3
123.1
104
341
391
0
0
Surrey
49.2
122.8
94
308
358
124
Qualicum
49.3
124.4
52
171
221
Nanaimo
49.2
124.0
30
98
Ladysmith
49.0
123.8
34
Chemainus
48.9
123.7
Duncan
48.8
Saanich
Victoria
Table 1
Vancouver Island Location Data
09-Mar-10
113
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
These calculations are most likely overly optimistic. They were performed to estimate the strength
of a vertically polarized Direct Wave at a distance. This presumes a flat earth without a radio
horizon, frequency dependent distances are ignored as are obstructions, and antenna gains are
assumed maximum as in an ideal ground mounted vertical.
Table 2.2.7-1 brings the reality to bear which indicates that the signals will not be as good as
these calculations might otherwise indicate.
QUALICUM – Approximately middle of town
Tx Ant
VEE
Vertical
Vertical VEE
Ez
V/m
2.7
3.3
3.6
Rx Ant
VEE
Vertical
Vertical
AF Rx
0.094
0.0368
0.0368
V
V
28.7
89.7
97.8
N
V
26.5
67.9
67.9
S/N
S Units / Q
1
2
3
S8 noise
S9 + 3 dB/ Q1
S9 + 3 dB / Q2
V
V
47.9
152.2
203.8
N
V
26.5
67.9
67.9
S/N
S Units / Q
dB
NANAIMO – Departure Bay
Tx Ant
VEE
Vertical
Vertical VEE
Ez
V/m
4.5
5.6
7.5
Rx Ant
AF Rx
VEE
Vertical
Vertical
0.094
0.0368
0.0368
dB
5
7
10
S9 + 5 dB / Q3
S9 + 7 dB / Q4
S9 + 12 dB/ Q5
LADYSMITH – Approximately middle of town
Tx Ant
VEE
Vertical
Vertical VEE
Ez
V/m
4.4
5.4
7.9
Rx Ant
VEE
Vertical
Vertical
AF Rx
0.094
0.0368
0.0368
V
V
46.8
146.7
214.7
V
V
33.0
122.3
201.1
N
S/N
V
dB
S Units / Q
26.5
67.9
67.9
5
7
10
S8 + 5 dB / Q3
S9 + 7 dB / Q4
S9 + 10 dB / Q5
N
V
26.5
67.9
67.9
S/N
S Units / Q
CHEMAINUS – Approximately middle of town
Tx Ant
Ez
Rx Ant
AF Rx
VEE
Vertical
Vertical
0.094
0.0368
0.0368
uV/m
VEE
Vertical
Vertical VEE
09-Mar-10
3.1
4.5
7.4
114
dB
2
5
9
S9 + 2dB / Q2
S9+ 5 dB / Q3
S9 + 9 dB / Q4-5
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
DUNCAN – Approximately middle of town
Tx Ant
VEE
Vertical
Vertical VEE
Ez
V/m
1.8
2.9
5.4
Rx Ant
AF Rx
VEE
Vertical
Vertical
0.094
0.0368
0.0368
V
V
19.1
78.8
146.7
N
V
26.5
67.9
67.9
S/N
S Units / Q
dB
-3
1
7
S8 noise
S9 + 1 dB / Q1
S9 + 7 dB / Q4
SAANICH - VE7PEP
Tx Ant
VEE
Vertical
Vertical VEE
Ez
V/m
0.94
1.9
4.8
Rx Ant
AF Rx
V
VEE
Vertical
Vertical
0.094
0.0368
0.0368
10.0
51.6
130.4
N
V
26.5
67.9
67.9
Rx Ant
AF Rx
VEE
Vertical
Vertical
0.094
0.0368
0.0368
V
V
9.6
23.4
62.5
N
V
26.5
67.9
67.9
V
S/N
S Units / Q
-8
-2
6
S8 noise
S9 noise
S9 + 6 dB / Q3-4
S/N
S Units
dB
VICTORIA – Oak Bay
Tx Ant
VEE
Vertical
Vertical VEE
09-Mar-10
Ez
V/m
0.9
0.86
2.3
115
dB
-9
-9
-1
S8 noise
S9 noise
S9 noise
VA7JW
APPENDIX VIII
EZNEC FIELD STRENGTH CALCULATION
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09-Mar-10
116
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APPENDIX IX
80 m VERTICAL DIPOLE ANALYSIS
Various models of an 80 m dipole are presented to investigate the Vertical Radiation patterns of
elevated vertical systems. Note that there is no radial ground system required for this antenna.
Model 1: Half wave vertically mounted center fed 80 m dipole at 1 foot above ground, that is, the
end of the lower element is 1 foot off ground. The height of this end is then raised 1/4
and then 1/2 above ground. This is clearly not a practical antenna for an Amateur
installation but serves to demonstrate a principle.
Model 2: Half wave vertically mounted off-center fed 80 m dipole at 1/2 above ground to
determine if the feed point location has any bearing on the vertical radiation pattern.
Model 3: Shortened (25 feet) half wave, center fed, 80 m dipole at 1/2 above ground to
determine if a shortened antenna has any bearing on the vertical radiation pattern.
Shortening systems (loading coils, tuning rods, stubs, capacity hats etc) will alter
parameters such as bandwidth and efficiency.
1.
MODEL 1A – Half Wave Dipole at Ground Level
Antenna View
SWR plot
Azimuth and Elevation Plots
Azimuth shows equal radiation over full 360 deg
Elevation shows horizontal radiation peaking at 15 degrees. Null is straight up.
These plots are as expected
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APPENDIX IX
80 m VERTICAL DIPOLE ANALYSIS
2.
MODEL 1B- Half Wave Dipole ½ above Ground ~ 62 feet
The height of the antenna has been raised by 62 feet.
Antenna View
SWR plot
Azimuth and Elevation Plots
By raising the dipole to ¼ , the development of higher lobes is evident due to far field effects, at
~ 1 km according to W7EL.
This characteristic was not anticipated, but is due to Far Field wave interference since the
elevated antenna has a downward radiation component that reflects off the ground and
recombines at a distance with the direct wave to form the far field (~ 1 km) radiation pattern.
3.
MODLE 1C – Half Wave Dipole ½ above Ground ~ 124 feet
Raise the antenna another 62 feet to 124 feet off ground.
Antenna View
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SWR plot
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APPENDIX IX
80 m VERTICAL DIPOLE ANALYSIS
Azimuth and Elevation Plots
The high lobe development continues with increasing height. Higher models are not done as the
phenomenon is already demonstrated.
4.
MODEL 2 – Half Wave, Off Center Fed Dipole ½ above Ground ~ 124 feet
The dipole is modeled as an off-center-fed dipole with the feed point offset in a 60-40 split.
Antenna View
SWR plot
Azimuth and Elevation Plots
Off-center feed does not affect the vertical radiation pattern.
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APPENDIX IX
80 m VERTICAL DIPOLE ANALYSIS
5.
MODEL 3 - Shortened (Loaded) Half Wave Dipole ½ above Ground ~ 124 feet
The loaded vertical is chosen to be ~ 25 feet high, typical of commercial verticals. A Loading Coil
is inserted in to each of the upper and lower legs of the dipole (2 coils in total). The reactance of
the coils was set to achieve resonance at ~ 3.7 MHz. The feed point impedance has minimal
reactive component (+j 8 ohms) but suffers from a low resistive component (4 ohms), resulting in
a high SWR (12:1)
Antenna View
SWR plot
The antenna is off-set from the Z axis to show the current distribution.
Azimuth and Elevation Plots
The loaded antenna radiation plot is not materially different. Slightly higher vertical lobes (50 vs
40 degrees) and slightly stronger (~ +4 dB) lower lobes (at 5 degrees).
6. Conclusion
The same high lobe development occurs with both the quarter wave vertical with radial system
and a vertical dipole. Feed point location does not alter far field nor does physical length.
Far field interference causes high lobe development in all cases of the vertical dipole models as
well as the quarter wave vertical models with a radial system.
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APPENDIX X
VHF / UHF PROVINCIAL REPEATER SYSTEMS
1. Southern Interior Repeater System
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APPENDIX X
VHF / UHF PROVINCIAL REPEATER SYSTEMS
2. Kootenay Repeater System
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APPENDIX X
VHF / UHF PROVINCIAL REPEATER SYSTEMS
3. B.C. Repeater System
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APPENDIX X
VHF / UHF PROVINCIAL REPEATER SYSTEMS
4. Northern Repeater System
Regrets for the poor copy quality but it can be seen as an extensive wide area network.
Please visit http://www.pgarc.org/ for further information or contact http://www.ve7av.ca/
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APPENDIX X
VHF / UHF PROVINCIAL REPEATER SYSTEMS
5. Vancouver Island Repeater System
Please visit http://www.islandtrunksystem.org/node/15 for further information.
You will likely have to register to view detail. Instructions are on the home page.
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APPENDIX XI
TECHNICAL ARCHIVE
Files used in this study have been posted to the NSARC Technical Archives site for viewing and
use.
File types are pdf, xls, EZ and txt
You will need Adobe reader for reading .pdf files, Microsoft Excel for reading .xls files and the
EZNEC application to open the .EZ files.
NOTE that the .XLS and .EZ are NOT PROTECTED in all cases. It is possible to destroy
formulas in some files through miss-use or mistake.
PLEASE DOWNLOAD to your own PC before using.
To access these files, go to
www.nsarc.ca > Tech Archive > Directory > and the following screen will appear,
www.nsarc.ca - /tech_archive/
[To Parent Directory]
Sunday, March 07, 2010
Tuesday, March 09, 2010
3:21 PM
1:05 AM
<dir> HF PREOC Study
218 readme.txt
Below is the directory structure. Click on the desired file, Open and Save to your PC, then RUN..
HF_PREOC_Study
|
| - Report
|
| - HF_PREOC_Prop_Study.pdf
|
| - PREOC-path_Geometry.pdf
|
| - Ionographs
|
| - foF2_hmF2_ByYear_V14_User.xls
|
| - GetMUFData_V14_User.xls
|
| - Antenna Models
| - Reference Antennas
|
| - 80m_Dipole.EZ and .txt
|
| - 80m_VEE.EZ and .txt
|
| - 80m _Quarter Wave_Vertical_radials.EZ and .txt
|
| - 80m vertical dipole.EZ and .txt
|
| - 80m Short Vertical dipole.EZ and .txt
| - Study Antennas
|
| - Vee_roof grid+ground.EZ and .txt
|
| - 33 ft Vert_roof grid+ground.EZ and .txt
|
| - Vert Vee_roof grid+ground.EZ and .txt
|
| - Calculator
| - S Meter_dBm_Calculator.xls
| - GetMUFData_V14_User.xls
These files are the property of VA7JW and are for your personal use only.
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