05-05-2022, 08:02 AM
Progress at a snail's pace, but progress. My plan is to first test the FM/audio and then move on to the video.
Testing the FM.
I powered up the TV for the first time without the HV. I forget exactly at which point (<90V), but as I turned up the variac I heard a snap. I immediately turned it off without looking for smoke, sparks, etc. I tried it again and the same thing happened.
I need to see what's up. I rotated the chassis so I could see the underside. I turned it on again and swear I saw an orange glow coming from the underside of the audio discriminator transformer and turned it off. Very bad. Almost, but not quite, unobtanium if bad.
What's going on. Is it a stray wire clipping? Is it silver-mica whisker?
I removed the transformer to take a closer look. The primary and secondary had continuity and weren't shorted. I meant to measure the 2 caps in it but forgot. There was no way I could see a wire clipping or anything else getting inside of the can to short.
I didn't want to commit to taking it apart to see the 2 caps inside, so I reinstalled it. Maybe I was hallucinating or any "whiskers" that had formed had burned off (pure speculation).
I powered up again. Nothing exciting happened this time. The voltage was set to 117V and all was well, except no sound.
I checked the speaker. The primary was OK, the secondary and/or voice coil were OK. I decided to disconnected one of the secondary transformer wires from the speaker so I could independently check the secondary and the VC. Well the VC had no continuity.
I grabbed a spare Transoceanic speaker and hooked it up and tried again. Finally I heard some noise. I then connected an "antenna" and received a few FM stations. The sound's not great, but it's alive.
The speaker connector plug and socket don't engage well. But that doesn't matter for now.
I'm trying to decide if I want to try to improve the FM reception before or after I try to get the video working.
The way I wrote this is a lot more orderly than the actual process was. Hey, it's my first TV and it has lots of parts
Testing the FM.
I powered up the TV for the first time without the HV. I forget exactly at which point (<90V), but as I turned up the variac I heard a snap. I immediately turned it off without looking for smoke, sparks, etc. I tried it again and the same thing happened.
I need to see what's up. I rotated the chassis so I could see the underside. I turned it on again and swear I saw an orange glow coming from the underside of the audio discriminator transformer and turned it off. Very bad. Almost, but not quite, unobtanium if bad.
What's going on. Is it a stray wire clipping? Is it silver-mica whisker?
I removed the transformer to take a closer look. The primary and secondary had continuity and weren't shorted. I meant to measure the 2 caps in it but forgot. There was no way I could see a wire clipping or anything else getting inside of the can to short.
I didn't want to commit to taking it apart to see the 2 caps inside, so I reinstalled it. Maybe I was hallucinating or any "whiskers" that had formed had burned off (pure speculation).
I powered up again. Nothing exciting happened this time. The voltage was set to 117V and all was well, except no sound.
I checked the speaker. The primary was OK, the secondary and/or voice coil were OK. I decided to disconnected one of the secondary transformer wires from the speaker so I could independently check the secondary and the VC. Well the VC had no continuity.
I grabbed a spare Transoceanic speaker and hooked it up and tried again. Finally I heard some noise. I then connected an "antenna" and received a few FM stations. The sound's not great, but it's alive.
The speaker connector plug and socket don't engage well. But that doesn't matter for now.
I'm trying to decide if I want to try to improve the FM reception before or after I try to get the video working.
The way I wrote this is a lot more orderly than the actual process was. Hey, it's my first TV and it has lots of parts
Can't think of anything witty.
Greg O.
Whitehall, PA
