Tube radio repairman out there?

[Indian Head]

Hi everyone

I am trying to resurrect a GE H-87 console radio that I have had since 1971, when it was given to me by my aunt. When I got it, the audio was so distorted you could not make out what was playing. An old-time repairman at the time fixed it and it worked fine for years. Several years ago, I turned it on and there were no stations received across the band. Recently, I pulled the chassis and hooked up audio to the "TV input" and, lo and behold, there was perfect, full-bore audio present. But no radio while trying to tune something in. I did a wax paper capacitor replacement and still no stations. I then hoked up a RF signal generator to the input of the 6SQ7 detector and a very very faint tone came through. Moving back to the 6SK7 IF amp, there was a trace of audio present, but so weak you had to put your ear to the speaker to hear it. So it kind-of-sort-of barely works. Next I checked the power supply voltages and they seemed close to what you'd expect, however, the schematic I downloaded from Nostalgia Air doesn't have voltages on it. I also checked the switches on the front for "manual tune" and "Television" (audio input) to make sure they were making contact. So far, nothing. I have reached the end of the road and don't know what to do next. I guess I'm looking for a reputable & reliable repair place who knows the old stuff and is willing to work on it. I'd prefer someone in the south-central PA. area. Can anyone either tell me what to look at next or perhaps know of someone who works on radios like this. Thanks! John (Mr. Indian Head)

[Nick_the_'Nole]

The first thing I'd do is check all the old resistors, which are probably the usual carbon comp type and have likely drifted significantly upwards in value over the years. The mica caps are also worth checking, if they're the old type that look a bit like dominoes.

[Electronic M]

If that does not pan out then perhaps an alignment would help(AM radios are infinitely easier than TVs to align).

[Reece]

Hi, I'm in South Central PA, and a pretty old radio man! If the set was working before and not now, I wouldn't touch the alignment until the set works again. You have to be able to hear the signal coming through all the way to align it, anyway. Several things to check.

1. You checked the bandswitch and tone switch: try cleaning them with spray and turning back and forth, and working the buttons, with the set on. Sometimes you'll hear an intermittent which points to a loose or dirty contact. With the set off, check each contact with an ohmmeter for continuity.
2. Test the 6SA7 and 6SK7 tubes.
3. See if those two tubes have DC on their plates, 6SA7 pin 3, 6SK7 pin 8, around 250 volts or so, with your negative voltmeter lead to chassis.
4. Check if screens on those two tubes have about 100 volts DC: 6SA7 pin 4, 6SK7 pin 6.
5. If voltages are there, see if the oscillator is working. Put another working radio tuned to 1450 next to your GE. Have the GE turned on and tune it up and down around 1000Kc. If the oscillator is working should hear a squeal or "rush" in the other set.

Check back and we can dig further into it.

[teevee]

Also check the plate voltage on the 6SQ7. I've seen a few open plate resistors on these.

[Radiotiques]

I am also a Radiotrician (repair tube radios) and located in Wilmington DE (Radiotiques.com). Check the antenna and oscillator coils for open windings as the symptoms you describe may be due to this. Also agree that alignment should never be attempted unitl the radio is repaired and working.

[old_coot88]

Originally Posted by Radiotiques

...Also agree that alignment should never be attempted unitl the radio is repaired and working.

Major mega-dittos on that.

[Indian Head]

Thanks for all the replies! Much appreciated. Have been busy with other more urgent tasks, but will let you all know how I make out with this.

[bob91343]

It may be the detector stage that isn't working. I am in Los Angeles but it's a long shot that you'd be near enough.