Para Dynamics PDC 600
The PDC 600 is an RF Watt, SWR, and Modulation meter. Power
rating was 1000 watts PEP. Three wattage settings of 10,100,1000. SWR FWD was
used to set the full scale (far left knob) by keying up the CB and adjusting
for the full-scale deflection (far right of the scale-red marker. The SWR knob
was set to the REF position to measure the reflected power/standing wave ratio
(SWR). All three readings could be read simultaneously.
Modulation was typically set in the same manner using a 1Khz
tone or some have been known to whistle into the microphone while keying the
mic. This was best accomplished using a dummy load as not to create unwanted
noise/chatter on the airwaves.
There were a number of PDC models:
1. PDC 600
There were a number of PDC models:
1. PDC 600
2. PDC 600P
3. PDC 600LP
4. PDC 6000
5. PDC 600T
5. PDC 600T
The PDC 600P used a more sensitive meter movement on the RF
power. The PDC 600LP stands for Lighted Peak. Wheat lamp bulbs were used to
create a backlight for the meter movements. Some end users had been known to
replace the wheat bulbs with various colored LED lamps. The PDC 6000 was the
1000watt version with a built in talk back circuit with a headphone output mono
jack to monitor the transmitted audio. The PDC 600T was actually a tuner that was built by Vectronics for Para Dynamics. At the time, both Para Dynamics and Vectronics were owned by Valor Enterprises, Inc., located in Piqua Ohio (now defunct).
The frequency range of the unit is 25-30MHz. Due to the nature of the directional coupler it isn’t recommended to use outside the designed frequency range as the insertion loss is rather significant outside that frequency.
The original PDC 600 meter movements were from Sam Woo Electronics.
SWR Meter Part # 5000900
RF Meter Part # 50001900
Modulation Meter # 5002900
4X4" PDC 700 Meter # 5069900
Troubleshooting chart
The frequency range of the unit is 25-30MHz. Due to the nature of the directional coupler it isn’t recommended to use outside the designed frequency range as the insertion loss is rather significant outside that frequency.
The original PDC 600 meter movements were from Sam Woo Electronics.
SWR Meter Part # 5000900
RF Meter Part # 50001900
Modulation Meter # 5002900
4X4" PDC 700 Meter # 5069900
Troubleshooting chart
Symptom
|
Recommendation
|
No Modulation- Has
Set
|
Replace C5 0.1mfd
capacitor
|
No Modulation/ Low
Mod (Set OK)
|
Check D7/D8
(1N4003)
|
No Modulation/Low
Set/Low Mod
|
Check D5 (1N4148)
|
No FWD Swing/Power
|
Check D2/D3
(1N4148)
|
No Mod /No FW Power
Swing
|
Check C4 .0024mfd
|
No Talkback PDC
6000
|
Check
Pot/Diode/Tighten bottom case screws
|
No Talkback PDC
6000
|
Check input jack
|
Wont Zero / Return
at zero
|
Check front/back
coil springs inside meter movement for debris
|
Wont Zero /Return
|
Adjust back pivot
point spring
|
Low Reading on 1000
watt scale
|
Check D2/D3 (1N4148)
|
Erratic meter
readings
|
Check wiring of
meter movement internal/external connections
|
Erratic meter
readings
|
Possible static in
meter movement cover, spray with anti-static spray
|
