/diy/ - Do It Yourself

Sup /ohm/, cross posting from /ham/

I'm trying to resurrect a Bearcat DX-1000 multiband receiver. Originally I had no digital function (see >>1117816) but I have managed to get that sorted rather easily. As I mentioned, reseating chips will often resurrect glitchy gear, I suggest you roll this into your first steps of troubleshooting of old kit if you don't already. We now stand with full control panel function, but no audio out. I have established that the audio chain is working by throwing a signal generator onto the input of its TBA810 amp, no problems there. As stated, I can tune local AM broadcast stations, but see no movement on the signal meter.

Based on pic related, I should be nosing around in, and upstream of, the AGC sections, right? This is where the signal meter is fed, and presumably, if the AGC section was faulty/dead, the squelch block would be stuck in "mute" mode, thereby preventing the mode switch from passing signal from whichever RF section/band is currently selected, to the AF chain.. r-right?

I'ma need to look up how all these blocks works so I know what signals I should be looking for, but I am so far out of my depth here it hurts. I know next to nothing about RF stages of devices, not much more about analogue beyond class B amps and light/motor controllers. I'd prefer the fault was in the digital sections to be honest, TTL I can work with.

Thanks legends.