Here is how you get upper channels on an 02A AM/SSB board. They produce different frequencies than the 02A AM only boards.
Cut the traces on both pins 10 and 11 on the PLL chip. Solder a 3.3k resistor across the traces where you just cut on each pin (bands on the resisitors are orange, orange, red for the first three bands). You can copy the illustration that Switch Kit provided, just cut the trace and solder a resistor in the same way on pin 10 as you do on pin 11. Take a DPDT center off toggle switch, put a wire from both the center poles on the switch to pin 8. Put a wire from the Pin side of pin 10 of the PLL to one end pole of the switch, and put another wire from the pin side of pin 11 on the PLL to the opposite pole of the switch. Diagram shown below.
0--0|-------> to Pin 10
0--0|-------> to Pin 8
0--0|-------> to Pin 11
Channels 12-27 will get you 27.425 to 27.595 when you tie pin 11 LOW (connects pin 11 to pin 8).
Channels 1-40 will get you 27.605 to 28.045 when you tie pin 10 LOW (connects pin 10 to pin 8).
You could probably get the lowers by tying pins 10 and/or 11 HIGH (connecting pins 10 or 11 to pin 9) per Switch Kit's description, but I have not messed with it on the AM/SSB boards, since I seldom go below channel 1 anyhow.
However, the VCO circuit on the 02A boards (both AM and AM/SSB) are rather narrow-banded, and only have a range of about 70 channels or so before you lose receive and transmit integrity. You CAN modify the VCO circuit, but it's not the easiest thing to do. Unless you really need to get the lowers, it's really not worth messing with. I'd just have the uppers and call it good.
Power and modulation tweaks: AM Power (deadkey) VR4, SSB power: RV11/RV2, Modulation, remove Q37 and Q38. (Normally, I am NOT a fan removing modulation limiting devices, like transistors, diodes, etc., as they can distort SSB badly. However on the 02A AM/SSB chassis, removing them doesn't seem to affect the audio quality in a negative manner.)
Let me look up the clarifier mod, and I'll post that when I find it in my notes.
-Exit