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Hi, I'm having an odd issue with my IC-7000.? It has an odd behavior that it will loose RX and TX when changing the frequency. Power cycling the radio allows it to come back but moving the dial will make it go deaf again.? I was able to verify that the 1st LO goes away when this error happens.? The 2nd and 3rd LO are still outputting fine.? I probed all the inputs of the 1st DDS, 1DST/PCK/PDT/PRES/1CN0/1CN1, but am unsure what a correct input looks like. I am able to verify there is a signal going into DDS FI201 but not DDS D301 when it is in the error state.? I have not pulled the metal shielding off to access IC301 directly yet.? I did noticed grounding PRES while spinning the dial will reset IC301 and the 1st LO will come back to allow RX for a brief moment.

I have changed out all the ribbon cables and traced the signals as close to DDS IC301 as I can.? I have noticed that PRES and 1CN0 are always set high. DST, PCK, PDT, and 1CN1 will pulse when I spin the dial.? Does anyone know the behavior of these inputs? Is there anything else I can try?

73,
Bill N6HA

I think I have resolved the issue.? I noticed there was oscillation on the 3.3v line on the DDS.? I added a 10uf electrolytic cap to the 3R3V pad above DDS R9 and ground to stabilize the voltage.? That seems to have done the trick.? I'm able to spin the dial with no issues.? I should probably replace the MAIN C1802 cap next but I can't find an identical part.

73,
Bill N6HA