I have no experience with this PLL and there are no service docs that I can find, apart from a datasheet for the C5121. This leaves me with some questions, that hopefully someone with experience knows the answers to.
1: The channel selection is stuck on channel 9. No up or down changes.
2: The radio does receive signals and will change when the VCO tuning is changed.
3: What is the unlock pin voltage level supposed to be when unlocked?
4: What is the VCO voltage when tuned and from where is the test point?
5: This radio has never worked correctly. It was given to me a long time ago and I just found it. I figured I would try it.
Thanks,
SL
1: The channel selection is stuck on channel 9. No up or down changes.
2: The radio does receive signals and will change when the VCO tuning is changed.
3: What is the unlock pin voltage level supposed to be when unlocked?
4: What is the VCO voltage when tuned and from where is the test point?
5: This radio has never worked correctly. It was given to me a long time ago and I just found it. I figured I would try it.
Thanks,
SL