Palomar SSB500
Documentation Project

CBTricks.com

Frequency Generation
PLL LC7120
       UPD858 (Early)
       MC145106 (Late)
AMC
  VR-408
Frequency Mod

1. Remove the covers from the unit and Locate the PLL chip pins on the bottom of the board.

2. Cut the trace shown in Figure A and solder a 4700ohm resistor across the cut.

3. Mount a 6 position rotary switch and wire it as shown in Figure B. Obtain a 1N914 diode and solder it to the switch.

4. A slight adjustment of the VCO transformer may be necessary for oscillation on high
channels above channel 60.

Slider

 

1. Locate diode D30 and remove it from the circuit.

2. Unsolder resistor R119 at one end and solder a wire from this resistor to diode D44.

3. Locate the wires on each end terminals of the clarifier control and follow them to the board. One of these wires terminates to a small resistor to ground. Solder a jumper wire across this resistor.

4. Locate the varactor diode next to each crystal and unsolder the ground side. Obtain a
3.3uh RF choke and solder it in series with the diode. (See Figure D)

5. Adjust each trimmer capacitor on AM - USB and LSB for proper slider range.

Adjustments
Mic Gain - VR-7
AM Power - VR-8
 

 

 


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we cannot guarantee that the instructions will work on every radio presented.