CNARC REPEATER
W6PWT.ORG
OVERVIEW
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HISTORY
SITE LOCATION
ACCESS TO SITE
SITE STRUCTURES
CNARC HARDWARE AT SITE
THEORY OF OPERATION
TECHNICAL ASSISTANT
HISTORY
• First club repeater activated in April 1987
Details in W6PWT.org 1987 Oct. archives.
• Scott Hendricks – KN6CLU purchased lot of
Gas Co. RCA TACTEC comm. Equipment.
• Scott buys S-Com 5K repeater controller
and Jim Kennedy integrates controller with
equipment.
• Joe and Gwyn Magaditch pick up 2M
duplexer
• Repeater installed and operated in Dick
Moll’s (N6CLU) home in Corona.
HISTORY (cont.)
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• Site purchased from HV Golf Club owner.
• Site developed without Norco Planning
Commission approval.
• Norco PC contemplated removal of site.
• Scott Hendricks presented alternate plan
for site usag.
• Negotiations successful, ComSites USA,
Inc. give city of Norco and CNARC/RACES
site usage.
• Provides equipment space in vault, space
on tower for antennas, and access to vault
power.
• No charge for site power or usage ad
infinitum.
HISTORY (cont)
2
• Fred Roberts –W6TKV requested and
obtained family permission to
acquire founding member (W6PWT)
call sign for CNARC repeater.
• Scott and Joe work with TASMA to
coordinate repeater on 147.060 KHz
+, pl=142.2 hz.
• Scott and Norm move repeater
hardware from Dick Moll residence
to permanent site on
Norco Hills.
SITE LOCATION
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STREET MAP
AERIAL VIEW OF SITE
ACCESSING THE SITE
ACCESSING THE VAULT
ACCESSING THE SITE
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Street Address (1234 Paradise Tower Rd.).
County main gate Penetration.
If your brave , take the trip.
Now you have to open the fence gate lock.
Next, open the vault door (keyed).
Enter code on alarm pad.
(hasn’t functioned for several years)
SITE STRUCTURES
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ANTENNA TOWER
CNARC ANTENNAS
VAULT # 1
VAULT #2
EMERGENCY GENERATOR
HARDWARE AT SITE
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2 meter/440 antenna w/50 ohm coax
1.2 GHz antenna w/hard line coax
RCA TACTEC RECEIVER
RCA TACTEC TRANSMITTER
S-COM CONTROLLER (5K MODEL)
INTERFACE LOGIC CONVERTER
4 UNIT DUPLEXER
POWER OUTPUT ATTENUATOR
13.8 VDC, 28 AMP POWER SUPPLY
THEORY OF OPERATION
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Repeater interconnect diagram
Function of the controller
Receiver operation
Decode module
Transmitter operation
Encode Module
Function of the duplexer
Purpose of the converter box
Purpose of the attenuator
Miscellaneous Repeater information
TECHNICAL ASSISTANT
NEEDED
• Equipment is getting very old
• Maintenance requires some
technical skills
• Current maintenance man is getting
old
• Will train qualified member to assist
• Please contact KN6CV if you would
like to volunteer for this position
THE END
Hope you enjoyed the show,
Copies of this PPS, on request
Will be e-mailed to members.
73 de Norm – KN6CV
Function of the controller
• Receive raw data , demodulated
data from the receiver.
• Decode dtmf codes, if present,
and respond.
• If no codes are present, pass
audio on to transmitter
microphone input.
• Turn on transmitter via. PTT line.
Receiver Operation
• Receive rf (147.660 MHz) signal from
duplexer.
• Detect subcarrier pl (162.2 Hz)
frequency.
• If pl frequency is correct, activate
CTCSS and COR signal lines to
controller.
• Demodulate rf signal and pass it on
to controller.
Decode Module
• Located in receiver.
• Frequency of comparator is
determined by
two precision resistors on the
module.
• If the comparator frequency is equal
to the decoded sub-carrier
frequency, the CTCSS line to the
controller is activated.
Transmitter Operation
• The transmitter is crystal controlled.
• The modulator operation is performed in the
plug-in crystal module.
• The encode module is located in the
transmitter section on the repeater.
• The transmitter frequency is generated by
tuning to the 12th harmonic of the crystal
frequency of 12.255 MHz, i.e. 12.255x12 =
147.060 MHz.
• The transmitter has a 100 watt amplifier
which has been set to it’s lowest level of
about 10 watts.
Encode Module
• The tone encoder was purchased
from
“Communication Specialists. Inc.”.
• The model SS-32P CTCSS tone
encoder is capable of generation
any of 32 pll tones.
• The tone is selected via. Dip
switches located on the module.
• The module is currently set for a
frequency of 162.2 Hertz.
Function of the Duplexer
• The function of the duplexer is to
allow the repeater to receive (listen)
and transmitt (talk) simultaneously
on the same antenna.
• The bandpass-reject duplexers are a
product of “Wacom Products, Inc.”,
model WP-641.
• The repeater, controller, duplexer,
antenna, and coax are all property
of the Corona Norco Amateur Radio
Club.
Logic Level Converter Box
• The RCA transmitter requires a positive
voltage to key the PTT input line.
• The circuit logic converts a ground
signal from the controller to a positive
voltage source for the transmitter.
• The COR (Carrier Operated Relay) signal
from the receiver also requires the level
change logic.
• The CTCSS (Continuous Tone Controlled
Squelch System) also required the logic
level conversion.
Power Output Attenuator
• When the transmitter output was set to 10
watts, a minor complaint was reported by
some users in the Costa Mesa ARC.
• The attenuator was inserted in the power
output line to limit the power to approx. 4
watts.
• No further complaints have been reported.
• The attenuator is a resistive device that is
designed to reduce the power output level
while maintaining the 50 ohm line
impedance.
Miscellaneous Repeater
Information
• Common power supply (13.8 VDC @
28 A), input from vault supply (120
VAC w/emergency backup
generator).
• Spare repeater parts available.
• Schematic drawings are available.
• Scom 5K Controller manual
available.
• Repeater operates 24/7 and is an
open system.
ANTENNA TOWER
REPEATER CONSOLE
D
DUPLEXER
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Emergency Power Generator
1234 Paradise Tower Rd.
Aerial View of Repeater Site
Block Diagram of Repeater
ANTENNA TOWER
REPEATER CABINET
Vaults 1 & 2
ANTENNA TOWER