Search results

Ok, worth a shot. Cold solder joints and loose grounds are common with these boards. Id start looking at the caps around the audio IC and rx audio chain. Some caps pass audio further down the chain, some shunt unwanted audio frequencies to ground, and both shape the audio to its destination...

With a dead key in ssb, are you reading movement on the modulation meter? I couldn't tell from the video, aside from the key click. I believe the TalkBack you hear is because of the way the TalkBack mod routes audio from the PA side back to the audio chip. Seems expected to me.

The volume and mic gain share a ground at pins 44 and 45. Maybe if that ground was missing, rx audio could feed into the mic gain and into the board. Lowering rx gain would stop it, but does lowering the Mike gain change it?

Edit... The volume knob (does not) run through the echo/vc/robot board. I bet that board is the source of your issue. Sorry, I crossed the lines on the schematic. It does sound like the robot though.

Probing deeper, and all things being equal, the IC506 5032p pins 12 & 13 aren't outputting a signal whereas the working counter does emit some timing signal spikes. I think it's either the IC506 or the chip it feeds, IC503. Checked both in the same mode with the same vco input. I might as well...

Great job, do you remember if the 32 MHZ changed in 10 khz increments when changing channel?

So, saying "that's a future me problem" and hoping for the best isn't sound retirement planning advice? Boy I'm screwed. Oh well, that's a future me problem. ; )

I thought he fixed blenders, you win.

Thanks Nomad, lots of good stuff in there. "Combover" haha. I had 1 donut come away from the board, so I soldered from top side. I have a few nos 5032 chips if needed, but don't want to swap until I'm absolutely sure that chip is bad. To replace it, I would probably use a Dremel and cut the...

This may be a little hindsighted, and I feel your pain, but whenever I open an unfamiliar chassis, I snap lots of pics of the wires and layout before I start manipulating anything. I rarely need the pics but it has saved my butt on the odd occasion. I especially do so if I know it may be awhile...

Right.

Is this the mod? It's the TSB I referenced..

I found that also, not sure what a kitchen tech is. Wow, I have verified signals into and around the various circuits and comparing frequency, amplitude and timing to another working counter and everything looks spec up to the 5032, then took a break. I can contend with the 92.200, but this...

Wow, I didn't even see that 27.1850 mhz designator. Take a look at the cbtricks schematic and see if it makes sense. I have both, the cbtricks and Sam's, but I have shied away from in depth C2K FC issues because I just don't have the big picture on its operation, so I can't explain it. I'm...

That's the one haha

I was brought this radio to try to fix, dead as a door nail. Pin rot on the pll, fixed. Loop oscillator was shot, replaced. Meter driver transistor had pin rot, replaced. Faulty capacitor between audio chain stage, replaced. Came alive and worked. Ordered a cap kit and recapped entire rig, but...

That 2312 looks fake, the 2166 is legit.

I have them all spot on at 13.80 volts. Now, these supplies include load sharing and I can't find the pin out. I want to let the supplies communicate with each other to share the load, and all I have found is a thread somewhere saying that the load share pin is the fifth pin, bottom of board...

Looking for a six pack of these, NOS preferred. Only accepting offers from reputable members, if you aren't well known don't bother. Thank you.

Looks like a ladder convention. Nice antenna.