NO.
R!V. NO.
ATM 1004
EM! Investigation for Array E
PAGE
DAT!
The results of the EM! investigation for Array E are
presented in this ATM.
Prepared by:
Approved by:
D. Fithian
i
OF
NO.
REV. HO.
ATM 1004
EM! Investigation for Array E
PAGE
DATE
TABLE OF CONTENTS
1.0
2. 0
3. 0
3. 1
3. 1.
3. I.
3. I.
3. 1.
3. 1.
3. 1.
3. 1.
1
I. 1
1. 2
2
3
4
5
3. 2
3. 2. 1
3. 2. 2
3. 2. 3
3.2.4
3. 2. 5
4.0
Introduction
EMC Requirements
EMC Analysis
Array E Subsystem Compatibility
Conducted Interference and Susceptibility
Power Lines
Signal, Timing, and Control and Analog Lire s
Radiated Interference
Radiated Susceptibility
Antenna Emanated R FI
Spectral Analysis
Compatibility of ALSEP with High Level
Radiating Sour c'e s
LSPEICommand Receiver Compatibility
LSPEICentral Station and Experiment
Compatibility
LCR U IALSEP Compatibility
SEP I ALSEP Compatibility
Sounder I ALSEP Compatibility
Testing
Page
1
1
1
1
2
2
5
7
7
7
8
8
8
9
9
11
12
12
ii
Of
NO.
REV. NO.
ATM 1004
EM! Investigation for Array E
PAGE
1
OF
DATE
1. 0
Introduction
ALSEP Array E, while similar to the previous ALSEP Arrays,
incorporates major <;lesign changes in the Central Station and
new experiment combinations. EMC for Array E requires not
only that the total system meet the EMI Specification for compatibility with the other elements of the Apollo Lunar Surface
Equipment System but that the experiments and Central Station
by compatible so that they will operate as a single system without interference with each other.
This.. ~TM documents the results of an investigation of the
Electroma_gnetic Compatibility (EMC) of the ALSEP Array E
System. The basic EMC requirements are first established,
an analysis is included to show that compatibility is theoretically
achieved in the design and interface requirements, and finally
a test program is defined to demonstrate that the hardware
meets the specification requirements for EMC.
2. 0
EMC Requirements
AL770000, the ALSEP EMI Specification, is intended to insure
adequate lunar performance of the ALSEP system and its compatibility with other equipment. It provides test methods and limits
for the ALSEP system and must also be regarded as a design
guide for subsystem performance. Essentially then, AL 770000
is the EMI Specification for the integrated ALSEP Array. The
subsystems must meet the specification for radiated EMI and
radiated susceptibility for the total array to meet it. It is also
necessary however, for Array E ALSEP to be compatible with
itself. This requires that EMI levels and susceptibilities for the
interface lines be established and that the subsystem be tested to
provide a margin of compatibility. These levels have been specified and are included in this ATM. The test program required to
prove a 6 dB margin of compatibility is also outlined in this ATM.
3. 0
EMC Analysis
3. 1 Array E Subsystem Compatibility
Each subsystem within Array E must individually meet radiated
and conducted interference and susceptibility requirements with
a six dB margin of compatibility to assure proper system performance. The following paragraphs present the EMC considerations
of each subsystem interface.
24
~ RI!V. HO.
NO.
EMI Investigation for Array E
ATM
1004~
PAGE
2
1
OF
DATE
3. 1. 1
Conducted Interference and Susceptibility
The interface lines connect components within the central
station and the central station to the experiments. They include
the 29 volt, 12 volt, and the 5 volt power lines, and the
signal, timing, and control lines. Note that the experiments
use only the 29 volt line for power. The 12 volts and 5 volts
are used exclusively within the C/S. With the exception of
the LSPE C/S electronics, the C/S experiment interface lines
are part of a flat cable running from the C/S to the remotely
sited experiments. In all cases the conducted EMI on interface lines is a composite of that induced directly acr_oss its
terminals and that due to cross coupling within the interconnecting harnesses and flat cables. In the case of the power
lines, each component shares a common impedance within the
PCU. Thus, the EMI on these power lines is a complex sum
of the EMI from each component. This is particularly true for
the 29 volt line where the DC-DC converter of each experiment
is an EMI contributor.
AL 770000 does not explicitly call for the measurement of conducted EMI and conducted EMI susceptibility on interface lines
within the system. However, the requirement that ALSEP be
compatible with itself requires that each of the subsystems
demonstrate a 6 dB margin of compatibility at these interfaces.
Specifications of the conducted EM! for each of these interface
lines have been developed. These values are included in the
Interface Control Specification (ICS) for each experiment.
Each experiment must also satisfy MIL-I-26600 (as amended
by MSC-ASPO-EMI-1 0).
3. 1. 1. 1
Power Lines
The total maximum conducted EMI from all sources
appearing on each of the power lines has been specified
as:
Power line
29 volt
12 volt
5 volt
mV peak-to-peak
150
100
100
24
r-
t'™ 1004
EM! Investigation for Array E
PAGI
3
DATE
These values were developed from an analysis of the contribution
of each of the subsystems operating from each of the po;ver sour~es
and the contribution of the PCU. The model used for th1s analys1s
is shown in Figure 1. The analysis was worse case in t~e sense
that peak to peak contribution of each source was added lmearly
across the PCU source impedance.
To insure that the total maximum conducted EMI values do not
exceed these specified values the contribution of each source
has been specified as:
Circuit
Power Line
EMI
PCU
Each New Experiment
HFE
29V
29V
29V
50 mV pp *
60 mA pp
500 mV PP
PCU
Command Decoder
Data Processor
12V
12V
12V
60 mV pp
100 mV pp
100 mV pp
PCU
Command Decoder
Data Processor
sv
sv
sv
40 mV PP
100 mV pp
100 mV pp
*Measured value. The total PCU output to any load, including.
converter noise and the effect of all other loads working at thelr
specification power noise feedback limits shall be: 1.50 mV p-p
for the 29 volt line, 100 mV p-p for the other powerhnes.
29 Volt Line
The 29 volt line provides the power to each experiment and also
the telemetry transmitter. Each of ·the expe~iments has its own
DC-DC converter operating from this line. T·he switching transistors within each converter contribute to EM! on this line. The
EM! contribution from each new experiment is specified as 60 mA
peak-to-peak into the specified source impedance of the PCU/PDU.
Each new experiment is required to measure conducted EMI on the
29 volt line and to meet this specification prior to integration with
the DVM. The UFE, a part of earlier arrays, is specified at 500
mV peak-to-peak conducted EMI on the 29 volt line. This experiment was tested and qualified for earlier flights and thus it was
not possible to change this specification for Array E. However,
Of
24
NO.
EMI Investigation for Array E
PAGE
I
RI!V. NO.
ATM 1004
4
OF
DATE
an HFE has been integrated with the DVM C/S so that the conducted
EMI from HFE could be measured. The maximum measured EMI
current was 28 mA peak-to-peak and the maximum measured EMI
voltage was 160 mV peak-to-peak. Thus the measured values for
HFE are within the specified contributions for the new experiments
and considerably below the value used for the calculation of the
total EMI noise on the 29 volt line.
Based on the latest measurements of experiment and PCU /PDU
conducted EMI on the 29 volt line but not including the above HFE
measurement the total conducted EMI on the 29 volt line to each
experiment is:
Experiment
LMS
LSG
LEAM
HFE
LSPE
PSE
Millivolts (peak-to-peak)
140
140
140
IIO
140
140
Each of the experiments and the S-Band transmitter are tested
for power line conducted susceptibility to the levels of MIL I
26600 (as 'amended by MSC-ASPO-EMI-10). The specified
levels of this document are 0. 2 Volt rms from 50 Hz to 15 kHz
and 0. I volt rms from 15 kHz to 150 kHz. These levels exceed
the specified values for conducted EMI on the 29 volt line by
greater than 6 dB over the frequency where the converter EMI
energy is concentrated. Thus, a 6 dB margin of compatibility
is demonstrated when conducted susceptibility is measured in
accordance with MIL I 26600.
12 Volt Lines, 5 Volt Line
The EMI on these lines is due primarily to the switching circuits in
the PCU and the digital logic circuits of the Command Decoder and
Data Processor. The condut:ted EMI on these lines will be measured
for the integrated system during integration-compatibility testing
of the DVM. Conducted EMI susceptibility measurement will be made
on the C/S components during component tests following the initial
DVM integration. The conducted susceptibility test levels of MIL
I 26600 are sufficient to prove a 6 dB mar gin of compatibility and
24
NO.
RII!V. NO.
ATM 1004
EMI Investigation for Array E
PAGE
5
OF
DATE
thus tests in accordance with this document are sufficient. Note
that the receiver, which operates from the 12 volt line, has been
tested to a level co£ 282 mV pp from I kHz to 10kHz and 400 mV pp
from 10 kHz to 250 MHz by the vendor. This is sufficient to
demonstrate the' 6 dB margin of compatibility.
'
3.1.1.2
Signal, Timing, and Control and Analog Lines
The source of conducted interference on the digital line is the
digital logic switching. The EMI is coupled both directly' from
the logic circuits and indirectly due to cross' coupling between
conductors in the interconnecting cables. The cross coupling
between conductors was investigated during the design phase of
Array E. The conductors within the C/S harness on which cross
coupling could result in false logic triggering were identified and
the amplitude of cross coupling as a function of cc!mductor length
was determined during this study. To insure that the cross coupling
would be within acceptable limits either the connecting lines have
been kept short (less than 7 inches) or an R-C network has been
placed across the connecting lines to. increase the rise and fall
times of level changes and hence reduce cross coupling. The
cross coupling between conductors of t_he experiment flat cables
was also investigated. It was shown that cross coupling was, to
a large extent, due to the relatively high inductance in the common
signal return line and that a reductfon in cross coupling was possible
if the number of signal return lin'es was increased. Therefore,
additional conductors of the flat cable have been assigned as signal
returns 1for the new experiments. Present plans call for th·e HFE
to retain the same interconnections as previously. Note that rise
and fall times for the digital circuits driving conductors within
flat cables will be controlled to fall within the 2-10 usee range as
in previous arrays. Therefore, cross coupling on the HFE flat
cable will be essentially the same as previously.
The defining specification for analog lines is that the analog voltage
shall not vary more than 10 mV during the 135 ,..usee sampling period.
The high impedance of the multiplexer input~ a minimum of 10 MA,
and the susceptibility of the equipment flat cables to cross talk and
radiated EMI results in EMI voltages at the multiplexer input terminals
greater than 10 mV. Most of the energy of the EMI is concentrated
at frequencies greater· than 5 kHz because (1) the cross coupling
24
MO.
REV. HO.
ATM 1004
EMI Investigation for Array E
PAGE
6
OF
DATE
increases with frequency; and (2) the EMI sources, the DC-DC
converters, the A/D converter frequencies, and digital logic
transients are at relatively high frequencies. Therefore the
I msec time constant R -C filter in the multiplexer reduces the
analog line EMI to a specified level. Although the analog line
EMI is not measured directly, system level analog tests
indirectly indicates compatibility. In these tests an analog
voltage is placed on the lines and the digital output must b'e
accurate to 1 bit or 20 mV with the system operating, i.e.,
the EMI environment of ALSEP itself is present.
Standard EMI practices are not feasible for the measurement of the
conducted susceptibility on the signal, timing and control lines.
The networks normally used to couple EMI onto the lines for these
measurements would in the case of digital lines effect the rise and
fall time of the signalS on the line. Furthermore, the amplitude
of the EMI induced by this means would vary over a wide range due
to the change in source and load impedance that accompany a digital
change of state. Therefore, the margin of compatibility for these
lines will be demonstrated indirectly by first measuring the EMI
level of the interconnecting lines on a peak-to-peak basis and then
comparing this value with the known noise margin for the logic
circuits employed. The measurement for each experiment will be
made with the experiment operating with its test set. Each of the
experiments is expected to meet the conducted EMI specification
of 100 mV peak-to-peak for these lines. However, the true margin
of compatibility will be determined based on measurements conducted
on the DVM during integration-compatibility tests. Each of these
interface lines will be brought out through a breakout box and the
conducted EMI on these lines will be measured. The Array E digital
circuits have a guaranteed noise margin of 400 mV. Thus the total
peak EMI voltage on these lines must not exceed 200 mV to guarantee
a 6 dB margin of compatibility.
Conducted EMI tests will be made on the signal, timing and control
lines of each of the C/S components during integration-compatibility
tests for the DVM. ' These tests will be used to determine the EMI
contribution of each component. If a component is the cause of out of specification operation, corrective action will be taken at this
time.
24
EMI Investigation for Array E
PAGE
7
DATE
3. I. 2 Radiated Interference
'
Each of the subsystems of ALSEP Array E must meet the
radiated EMI requirements of AL770000 to insure that the
total system will meet these requirements. Therefore,
each experiment and the C/S is required to measure radiated
EMI in accordance withAL 770000 and be within the specified
levels of this document.
Each of the new experiments will be tested in accordance
with MIL I 26600 (the same as AL770000 for radiated EMI)
for radiated EMI prior to integration with the DVM. The
HFE, the telemetry transmitter, and the command receiver
have been'tested in accordance with MIL I 26600 as part of
their acceptance testing. Radiated EM! for the integrated C/S
will be mdae in accordance withAL 770000 as part of DVM
test.
3. I. 3 Radiated Susceptibility
Each subsystem must meet the radiated susceptibility·requirements
of AL 770000 for the integrated system to meet this specification.
Each new experiment will be tested in accordance with AL770000
prior to integration with the DVM. HFE was tested in accordance
with AL770000 prior to integration with earlier arrays. The C/S
radiated susceptibility will be tested in accordance withAL 770000
during the DVM integration-compatibility tests.
3. I. 4 Antenna Emanated RFI
Antenna emanated R FI for the telemetry transmitter are defined in
AL 770000. These values will be retained for Array E, i.e., 'the
spurious rf output of the transmitter in the keydown mode shall
not exceed the following limits:
Of'
24
NO.
RIV. HO.
~TM 1004
EMI Investigation for Array E
PAGI
8
DATE
-20 dBm at all frequencies between 2 MHz and 10, 000 MHz
except as follows:
-60 dBm at 243. 0 MHz, 259. 7 MHz, 279. 0 MHz and 296. 8 MHz
-90 dBm at 2101.8 MHz, 2106.4 MHz, and 2119 MHz
For system level tests the spurious output limits at the antenna
cable output shall be 10 dB greater than those specified above.
A specification change to AL 770000 will be required for Array E
to specify the level of antenna-conducted spurious emanations for
the LSPE transmitter and antenna.
Based on an analysis that
considered both the operational requirements of the LSPE and the
susceptibility of ALSEP the following specification was developed
and is a part of the LSPE ICS:
LSP Transmitter Pulses OFF - In the LSP Transmitter
Pulses Off mode of operation (transmitter off, transmitter;
oscillator on} the spurious RF output of the LSP transmitter
measured into a matched load at the ant,enria terminals of
the cable to transmitter antenna shall not exceed the following
limits:
+10 dBm at 20. 600 MHz
-90 dBm at 2119. 0 MHz
-10 dBm at all other frequencies between 2 MHz and 10,000
MHz
LSP Transmitter Pulses ON - In the LSP Transmitter Pulses On
mode of operation (transmitter and transmitter oscillat?r on)
the harmonic and spurious RF output of the LSP transmitter into
a matched load at the antenna terminal of the' cable to the transmitter antenna shall not exceed the following limits:
-+ 10
dBm at 20. 600 MHz
+46 dBm at 4L 200 MHz
+10 dBm at 82. 400 MHz
-90 dBm at 2119.0 MHz
-10 dBm at all other frequencies between 2 MHz and
10, 000 MHz
A discussion of these specifications can be found in Section 3. 2 .. 1
and 3. 2. 2.
OF
24
NO.
REV. NO.
ATM 1004
EM! Investigation for Array E
PAGI
9
DATE .
3. I. 5 EM! Spectral Analysis
Tables 1 and 2 identify potential noise sources internal and external
to ALSEP respectively. Tables 3 and 4 identify the frequency bands
of susceptible circuits internal and external to ALSEP respectively.
Comparison of the frequencies and their harmonics listed in tables
I and 2 with the susceptible bandwidths listed in tables 3 and 4
results in only one identified potential problem. That is the third
harmonic of the LSPE transmitter falls within the bandwidth of
the first IF of the ·s-Band receiver. In addition, however, the
LSPE radiates power levels that result in field strengths well
above the level for susceptibility measurements and the trans~itters
of the Lunar Communications Relay Unit (LCR U) and the Surface
Electrical Properties experiment (SEP), under certain conditions,
can result in fieid strengths exceeding the susceptibility measurement levels. Each of these requires further consideration.
3. 2
Compatibility of ALSEP with High Level Radiating Sources
The LSPE, internal to ALSEP, and the LCR U, SEP, and Sounder,
external to ALSEP are sources of high level radiated EM! added
to the RFI environment with Array E. The radiated .levels of the
LSPE transmitter exceeds the radiated susceptibility test levels
while the LCR U and SEP radiated levels can under some conditions
exceed this level. Thus each of these sources is considered further.
The pbwer density at ALSEP due to the Sounder is well below the
radiated susceptibility test level and therefore tests in accordance
withAL 770000 ar..e sufficient to show compatibility. Compatibility
with the LM, EVCS and CSM are covered by the specifications of
AL 770000 and therefore do not require additional~ consideration.
Note that these systems are not operational during the period that
the LSPE antenna is radiating.
'
3. 2. 1 LSPE/Command Receiver Compatibility
Figure 2 is a plot of the calculated field strength at the C/S due
to the LSPE antenna ernan::ttions as a function of frequency for a
30 foot and 60 foot separation between the LSP antenna and the C/S.
The field strengths at the C/S that result from radiated suscepti~
bility tests in accordance with AL770000 are also shown for comparison. The field strengths due to the LSPE antenna ematlons are
OF
24
NO.
R!V. NO.
ATM 1004
EMI Investigation for Array E
PAGE
1O
DATI
based on the specified antenna emanated levels for this experiment
and the calculated efficiency of the dipole antenna. Note that the
field strength due to the LSPE at the third harmonic ( 123. 6 MHz)
is 26 dB below the radiated susceptibility test level. In addition the
third harmonic radiating directly fr9m the LSPE C/S electronics
and transmitter and the interconnecting cables with the LSP antenna
replaced by a matched load is specified at the level of AL 770000.
Thus the fact that the receiver has successfully met the requirements
of AL770000 . for radiated susceptibility
at this frequency demon-.
I
strates a sufficient margin of compatibility. However there remains
the possibility that the high transmitter output power at 41. 2 MHz
.
I
could be converted to third harmonic withiri the receiver. The field
strength at the C/S can be as great as 37 dB above the susceptibility
measurement level of AL 770000. Thus further tests specifically
designed to determine LSPE/ command receiver compatibility will be
run. These tests are described in section 4!.·t>. '
·
3. 2. 2 LSPE/Central Station and Experiment Compatibility
The RFI field strength at the central station and experiments due
to the LSPE can be as great as 37 dB above the specified test levels
of AL770000 for radiated susceptibility. Thus compatibility will
not be demonstra~ed with normal EMI susceptibility testing. Therefore a special test program has been designed to demonstrate this
1
compatibilit'y. The tests are described in section 4. 0.
3. 2. 3 LCRU/ALSEP Compatibility
The relatively high powered transmitter and high gain antenna of the
LCRU represents a potential RFI problem to ALSEP. For normal
operation, the LCR U antennas will be pointed toward earth and the
LCR U R F power directed toward ALSEP will be at the antenna side
lobe level. However~ if the LCR U antenna is inadvertently pointed
directly at ALSEP, the field strength at ALSEP can reach potentially
damaging levels.
Figure 3 is a plot of the power density at ALSEP due to the LCR U as
a function of LCR U I ALSEP Separation and antenna pointing. Should
the LCR U high gain antenna point directly at ALSEP from a distance
of 70 feet' while the LCR U is operati~g in the high power mode, the
power density at ALSEP is approximately 24 dB above the radiated
OF
24
NO.
RI!V. HO.
ATM 1004
EMI Investigation for Array E
PAGE
11
OF
DATE
susceptibility specification lev~l and the field strength is approximately 11 volts per meter. Although a direct comparison is not
possible, it should be noted that measurements made during LSP/
system tests at 41. 2 MHi for similar field strenghts showed tha~
potentially damaging voltages were induced on the flat cables connecting the Central Station to the experiments.
If certain operating restrictions are placed on the LCR U, i.e.,
if it is not operated within 100 feet of ALSEP and if ALSEP is not
illuninated byLthe main lobe of either LCR U antenna, testing ALSEP
radiated susceptibility in accordance with AL770000 is sufficient
to show compatibility. If it is not possible to place these restr-ictions
upon LCRU operation it will be necessary to test ALSEP to the.greater
levels shown irl. Figure 3 and possibly tprovide further ~FI protectidn
to ALSEP. The test could be run on the Array E DVM, immediately
following a similar test with the high power LSPE transmitter. It
would be highly desirable to have a LCR U transmitter for these tests
so that the actual radiated spectrum would be used in the tests.
Then in addition to measuring the induced voltages at ALSEP, the
tests would also determine if ALSEP is susceptible to specific
frequencies within the LCR U spectrum.
3. 2. 4 SEP/ALSEP Compatibility
The SEP represents another source of radiated RFI to ALSEP.
The location of the SEP in relation to ALSEP will determine if the
SEP radiated levels are greater or less than the ALSEP susceptibility
level measurements. Preliminary calculations show that a separation of 200 meters would insure that SEP radiated levels are below
those used for radiated susceptibility tests and compatibility would
be demonstrated with tests in accordance with AL770000. In addition,
because present plans for SEP operation do not include turn off of
the SEP transmitter at the completion of data collection, the SEP
transmitter will be operating when the LSP recievers are activated.
Therefore the SEP transmitter represents a potential source of
RFI to the LSP receiv_~~· _Figure 4' is l1 plot of susceptibility of
the LSP receiver referred to the LSP receiver terminals. Note tB.at
at 32 MHz an EM! level of greater than -40 dBm is unacceptable.
Assuming that mismatch and polarization loss at the LSP receiver
antenna is 20 dB and that 'the SEP antenna is a matched half wavelen'gth dipole, the minimum acceptable distance between the SEP
transmitter and a LSP receiver is 1250 feet.
24
NO.
REV. NO.
ATM 1004
EMI Investigation for Array E
PAGE
12
DATE
Hence the extent to which SEP I ALSEP compatibility is proven
depends on the mission guidelines. When the minimum operating
distances b~tween SEP and ALSEP have been determined it will
be possible to calculate RFI levels and to design a test plan to
demonstrate a 6 dB margin of compatibility.
·
Another factor that must be considered, is the possible effect of
SEP transmissions on LSP explosive charges. It is recommended
that the SEP radiation be included in the lunar RFI environment
for the LSPE RFI susceptibility tests that were tentatively .
scheduled for 14 June 1971. Reference: LSPE (Lunar Surface
Profiling Experiment) RFI Susceptibility Test Meeting Minutes;
Wiseman to Curry letter received 22 April 1971.
3. 2. 5 Sounder I ALSEP Compatibility
The Sounder signal is transmitted from the CSM as it orbits
the moon. Although the transmitter level is high, the fact that
it is transmitted from orbit via a relatively low ga.in antenna '·
reduces the worst case field strength a,t ALSEP to well below the
level of the ALSEP radiated susceptibility test. For instance at
a range of 110 miles the field strength at ALSEP due to the Sounder
is approximately 40 dB below the radiated susceptibility test
level. ·
1
4. 0
Testing
Each of the experiments, with the exception of HFE, will be
tested as outlined in this ATM and as shown in Table 5. HFE
has already been tested in accordance with' AL 770000 prior to
integration with early arrays and there are no present plans
to repeat these tests. However, because HFE did not meet
MIL I 26600 for conducted interference a special test has been
run with the Array E DVM CIS. The results of this test show
HFE is compatible with the requiremehts of Array E. The four
new experiments will be tested to insure that the conducted EMI
on the power line due to the experiment will meet the specifications of the ICS. Conducted susceptibility on the power line will
be measured in accordance with AL 770000. Susceptibility on
digital lines will not be measured. Radiated EMI and radiated
susceptibility will be tested in accordance with AL770000.
OF
24
MO.
RI!V, MO.
ATM 1004
EMI Investigation for Array E
PAGI
13
OF
DATI!
These tests will be performed prior to integration of the
experiment with the DVM C/S. In addition, special tests will
be conducted with the LSP transmitter and the command receiver
mounted to the DVM thermal plate and the LSP antenna deployed,
to determine LSPE/ command receiver compatibility and EMI
levels on the experiment flat cables and C/S harness due to the
LSP radiated signal'. This test is to insure that LSP transmitter
induced EMI levels will not result in damage to other subsystems
and provide confidence that total ALSEP operation wUl not be
adversely affected. These tests are scheduled to be run prior to
integration of LSP~ with the DVM C/S.
Further EMI testing is planned during integration-compatibility
testing of the Array E DVM. The interconnecting cables will be
brought out through break-out boxes during 'integration, permitting
the measurement of conducted EMI on each cable. Following
these tests, each co·mponent of the C/S will be run through a
series of tests including EMI tests. Present plans call for conducted EMI and conducted susceptibility to be measured for each
component during this test phase. The C/S components will then
be reintegrated into the DVM C/S witho'ut break-out boxes. The
DVM C/S will be EMI t~sted in accordance with AL770000. A
special test is planned with the DVM C/S, the LSPE and the system
test set to confirm EMI compatibility. Further tests may also be
required to prove ALSEP/LCR U and ALSEP/SEP compatibility.
ALSEP/LCR U compatibility tests if necessary would be run
following LSPE cobpatibility tests with essentially the same test
set up. ALSEP/SEP compatibility tests if necessary woUld be
run during the regular radiated susceptibility tests with increased
levels at the SEP frequencies determined when the minbnum operating
range is specified.
I
Figure 5 shows the EMI test program flow.
24
Page 14 of 24
Pc" I PtJ t.J
Fo~
C:6( viVAL eNr c;Acu,T
EI'1Z
.4-AlALYS'IS"'
~(f)
Pe.u
pol)
. I
.
I
OL---------------~--~----------~--------4----'' '~
FIG-URE
I
Q..
In
-.J
~
4J
~
~
V)
0--\/l
\\.""'
"'(
'u~
\n'lb
V)
--..J...._
"'t
~Q
\:---
~ \\)
~<(
t--.~
,4:
~""t
~\\J
V)<
~q:
~~
~
~ ......
. ---.1
~~
~
0
:
~
~
~
""
,;:0
-...
0
~
'!.
c
4..
&,
d
~
~
'\J
a_~
~
~ q:&
~
C)
"J
0
~
~
0
<ij
0
~
"U
0
<:\!
't>
'
Ll.
t"'t)
:::t
~
)..
'V
\u
..J
-=<
Qf
I
(\(·
\o
\l
\,\)
~
-~
c(}
0':,)
-t"t
~
'
-<:;
ro
.......
\'(
_())
Page 15 of 24
0
0
0
('(
~
-~
_J__j~JllllJII_LILL.I_L___ J
ulI_LI_LI
LLII
. .~. -1-'----L-~--'-1-II..u.II-L.Iul'~.1~____:61Ljl
!Jlll._.___l
~~~.a~(J..t70A .FIL~Na?JJ.9 (]7.31::/
I
!
Page
-,
161 of 24
I
I,.
~(
"
~
l-
l.lJ
~
~
~
......
k
l!J
~
~
VI
'-
C\
0
()
Cl
'
/
/
1\
~
0~
~f
.f .
,Y
~r
·"
~~;
}
·/
:J
lr>
I
6
1"-
\.() ,
..~
/
~
V1
~
_o .
\:)
1
\,
M
L.---....!..'----''----'1...1---'..LI____~'I_____:,_..~-I___,. . J. I___
~ ' /M 8 P
;I< ..lJ S:(Y-3 (( 't}::l (Y) (}cf
;~
"""
.,,
t-'~
""
))
~'
'l.
\{}
C)
::)
VI
'l)
\v
\D
~')
"
~J
,I
li)
(\/
C\.
\f)
'-J
'•
'""-.,
'
1-1
Ni
!ijj
~
4.i
'
~
~
~I
I
t
~
"'1
~
s
IU3
~
I
·"_)
'I'
I_____L -'-~ l___ I
I
W>TP 7 .;}/13 7
~
~
(5
~
\J
r)
K
~
~~
I
\0
'·i
~
~
I
"()
~I
~
~;
~i
~·
'
0
"('">
LL_____I -·
-------
·0
---
-,::)
I
~
I.
">
~I
Q
f
~
Q
!'\!
~
S!
':)
"<
\)j
()
)..
~
:::t
\-l_
"'-..
~
0
~
lu
~
gle 17 of 24
.._g
0
ll)
0
¥
\)
~
~~
!·
...
·~
ll•
~
~ ~~~
~
~~·
s
~~
~;
"1:
~~·
fo.;
.
··'
i
--.·
:
l ;
' ::
I
',
:. ~
I
~
1'
'
: :·
'
...
: ""1•
; l
j
'
'
l'~
, , l. .
;:
''
;
~- --~.,
''
'
, '
!
!jl'
' '
.
I
'
J!ltfitgt..;, ~d ~o-:;' w.aJ.s~.s.. t
~
)
'
WAt:r
~~;~2.¥/V.r. 'I
: •-r..Jh.:t~kiJJ?JfJS:.au zvr:a ·
'· ·'
$.3(VJ,.7 3
/VOI..t..tleff)3J.NI:
~OOa~
·
~-1-~----~.-~
~
!~
~~
~
s
~~
"
I
I
I
~
·I
I
I
-- ~
~-----.---+
I
r-------~
:
I
I
<\.I
\1)
\u I
rJ....,I
I
; I
I
L- -1
t
8-~
~~~
~'-
-J
..-~
!
;
!
'
Page 18 of 24
~-"-
t·YI
(ti:~
p:
NO.
ATM 1004
EMI Investigation for
Array~
PAGE
19
, 'REV. NO.
Of.
DATE
Table 1
Potential EM! Sources Within the Array E C/S and Experiments
Frequency
Source
Comment
3Hz
LSG
53 Hz
530Hz
1kHz
1. 06 kHz
2. 0 kHz
3. 3kHz
3. 533kHz
5.0 kHz
7. 0 kHz
8. 0 kHz
8-10kHz
10kHz
10kHz
10kHz
10kHz
10.6 kHz
11kHz
14kHz
25kHz
28,26 kHz
100kHz
2.0 MHz
2. 0 MHz
LSG
C/S
C/S
C/S
C/S
LSG
LSP,C/S
LMS
LMS
C/S
C/S
HFE
LMS
LEAM
LSPE
C/S
LMS
LSG
LEAM
The relay driving the mass change servo motor switches at 3 Hz while in
limit cycle mode
Screw servo and tilt servo motors, surge currents of 30 rnA
Slow downlink data rate, derived from 2. 036 MHz oscillator
Command data rate, derived from 8 kHz VCO in demodulator
Normal downlink data rate, derived from 2. 036 MHz oscillator demodulator
Command subcarrier frequency, derived from 8kHz VCO in demodulator
Stabilized oscillator
LSP mode data rate, derived from 2. 036 MHz oscillator
Low voltage power supply
Electron multiplier power supply
Demodulator VCO
Power conditioner
Power converter
Filament power supply
Power converter
Power converter
Available high data rate, derived from 2. 036 MHz oscillator
Ion pump power supply
Heaters and power converter
Clock oscillator
Timing signal to LSPE multiplexer
Sweep high voltage power supply
Calibration oscillator
AID converter osci-llator,
C/S
LMS
LMS
LSPE
~4
"XTM
1004
RE'f. HO.
EMI Investigation for Array E
PAGE
DATE
Table 1 (Cont)
Frequency
Source
Comment
Z. 036 MHz
CIS
38 MHz
41. Z MHz
95 MHz
111 MHz
190 MHz
1997. 3 MHz
ZZ75. 5 MHz
CIS
Data Processor oscillator, all data processor/multiplexer
timing is derived from this oscillator
Bx transmitter fundamental frequency
LSPE transmitter frequency
Teledyne transmitter fundamental frequency oscillator
S-Band receiver fundamental oscillator and Znd mixer LO
Bendix transmitter frequency at the modulator
S-Band receiver first mixer LO
Transmitter carrier frequency
LSPE
CIS
CIS
CIS
CIS
CIS
20
Of'.
24
NO.
A TM l
PAGE
EMI Investigation for Array E
QQA I REV. NO.
21
DATE
Table II
ALSEP RFI ENVmONMENT
DUE TO EXTERNAL SOURCES
FREQUENCY MHz
SOURCE
COMMENTS
32_jj
SEP
SEP
SEP
SEP
SEP
SEP
5. 0 to 5. 33
15.0 to 16.6
150.0 to 166.0
SOUNDER
SOUNDER
SOUNDER
1.0
2. 1
4.0
8. 1
16.0
259.7
279.0
296.8
2101.8
2106.4
2119.0
2265.5
2272.5
2275.5
2276.0
2278.;0
2278.5 .
2279.5
2282.5
2287.5
SEP signal transmitted via crossed dipole located
(nominally) 200 ·meters from LM
•
EVA-I, EVA-2
LCR U, LM, CSM
EVA-2
EVA-l,EVA-2
LCR U, LM, CSM
MSFN
MSFN
MSFN
LCRU
CSM
ALSEP
ALSEP
ALSEP
ALSEP
ALSEP
LM,P&F
CSM
85 watts~
85 watts Swept frequency, transmitted from CSM
85 watts
Extra~ehicUlar communication system (EVCS)
EVCS
EVCS
LCR U, LM uplink carrier frequency
CSM uplink carrier frequency
ALSEP uplink carrier frequency
Downlink carrier frequency, +8dBW, 38 inch parabola
FM downlink
Array E downlink carrier
Array D downlink carrier
Array A-2 downlink carrier
Array A downlink carrier
Array C downlink carrier
_
__
Downlink carrier for LM andParticles and Fields Subsatellite .
PM downlink carrier
-\
or.
24
I REV.
MO.
MO.
ATM 1004
EMI Investigation for Array
..1:!..
PAGE
22
DATE
Table 3
Potential EMI Susceptible Circuits
Frequency
,v 1Hz
0-10 Hz
0-16 Hz
95-105 kHz
10.7 MHz + 265kHz
41.2 MHz
121.66 MHz + 2.2 MHz
2119 MHz
-
LSG free mode filter
LSPE geophones - above 10 Hz roll off is at 40 dB/decade
LSG seismic filters
LEAM microphone
S-Band receiver 2nd IF, NBW=:: 530kHz, -60 dBm
LSPE receiver, sensitivity is -130 dBm at band center,
-85 dBm at + 50 kHz
S-Band receiver 1st IF, 3 dB BW = 4.4 MHz, -104 dBm
S-Band receiver frequency, signals greater than+ 1. 5 MHz
from f and at levels -50 dBm and less will not interfere
0
Of.
-..:
MO.
REV. MO.
ATM 1004
EM! Investigation for Array E
PAGE
23
-·-:---*
OF.
DATI
Table 4
External EM! Susceptible Circuits
Frequency
MHz
~stem
243.0
259.7
279.0
296.8
2101.8
2106.4
2119.0
EVCS
'EVCS
EVCS
LM &: LRV
CSM
ALSEP
1.0
4. 0
8. 1
16. 0
32. 1
SEP
SEP
SEP
SEP
SEP
SEP
5. 0 to 5. 33
15. 0 to 16. 6
150 to 166
Sounder
Sounder
Sounder
z. 1
Emergency communications frequency - radiated level specified
as less than -60 dBm
Radiated level specified as less than -60 dBm
Radiated level specified as less than -60 dBm
Radiated level specified as less than -60 dBm
Uplink carrier - radiated level specified as less than -90 dBm
Uplink carrier - radiated level specified as less than -90 dBm
Other ALSEP Arrays - radiated level specified as less than -90 dBm
Receiver sensitivity -130 dBm
Receiver bandwidth 1 kHz
.-.-.,...
~.Jr~c.
...... "
.
,.,... -·
NO.
EMl Investigation for Array E
ATM 1004
PAGE
24
I
REV. NO.
Of,
DATE
Table 5
Subsystem EM! Tests
-Test
Technique
Specification
Power line conducted
Signal, timing and
control lines
Radiated
Power line conducted
susceptibility
Signal, timing, and control lines conducted
susceptibility
Radiated susceptibility
current or voltage probe and scope
current or voltage probe and scope
res
AL 770000
AL 770000
AL 770000
AL 770000
Noise voltage measured in
system configuration
ICS - Guaranteed Noise
Margin
AL 770000
AL 770000
Measurements in system
configuration
10 mv variation during
135~ec sample period
Analog lines
ICS
\!
2<t