Hello everyone, i have a old 2950 here, works, but had a few problems, so was going to go thru the alignment. started with the PLL, and got to step 3 adjusting for 10.240mhz. the adjustment is VC1, it makes no change in the freq sampled from L61 as instructed. I took VC1 out, and checked it on my lcr meter, print says its a 20pf, and it will adjust a little beyond that, so its working. now the counter is showing 10.240-10.250, what makes it change is turning the radio over or touching the case, i have checked all the grounds on the radio and there all soldered and all screws are tight. but there seems to be something up with the grounding i think, i can not clip ground lead to chassis as it will not settle, meaning it fluctuates quite a bit, i ground it to the incoming 13.8 line and its fine. the coil that comes off the positive and negative to pcb, looks like it has been hot once or twice, there is a little black on it, could that be an issue, if so what can i replace it with, i have quite a few old radios here with similar components from incoming power to pcb.
akso i can touch the case of the radio and the 10.240 will change when i touch the case. i have never had one have an issue with the alignment on the PLL. has anyone else had this issue? I assume the crystal is good as im am seeing 10.240 up to 10.250, i just have no adjustment on vc1.
any ideas?
Justin