Zenith porthole 12" console

[Adam]

I swapped in a coil (of unknown value) and got: weak sound, crappy video, and sync that won't stay put (H or V). I tried several different coils and got the same results, so even though I'm not quite sure what to put for that coil, I'm fairly sure the problem I'm looking at now lies elsewhere.

I'm going to poke around the AGC amp tube and check the voltages, but I have a suspicion, with all the other goofy stuff that was done to this set, that someone got in there long ago and twiddled every adjustment they could find and goofed up the IF alignment, video and audio.

[old_coot88]

Originally Posted by Adam

I swapped in a coil (of unknown value) and got: weak sound, crappy video, and sync that won't stay put (H or V). I tried several different coils and got the same results, so even though I'm not quite sure what to put for that coil, I'm fairly sure the problem I'm looking at now lies elsewhere.

That's correct. The inductance value is not critical, since the coil serves no other purpose than as a choke. In fact you could probably jumper it completely and never know the difference.

...I have a suspicion, with all the other goofy stuff that was done to this set, that someone got in there long ago and twiddled every adjustment they could find and goofed up the IF alignment, video and audio.

Actually it does not show symptoms typical of video IF misalignment, namely strong
smearing-out and ringing of fine detail in the pic. Fine detail looks pretty crisp. That's not to say the audio IFs haven't been messed with, though.