RCA Victor model 4-X-641

[electra225]

I have had this set for awhile. I was listening to it this afternoon when it started fading. I could bang on the cabinet and the audio would return. I haven't done much to it, just changed the filter caps a few years back. It needs a good cleaning, recap, then a good alignment. I can't get anything done in the shop on scheduled projects. These little jobs appear and interrupt progress. I don't suppose there is any hurry......

[William]

That is a nice 6 tube radio with phono input. I had to Google it to see what it looked like.

https://www.radiomuseum.org/r/rca_4_x_6 ... 40rc1.html

Bill

[electra225]

I took some pictures, but I messed them up somehow. I'll have to do it again. This is a dandy radio, with its "Golden Throat" speaker. I wonder how a hot chassis radio works with a 45 rpm record player accessory. I would think the tone arm could be hot and there might be a hum issue. I'd probably run the radio on an isolation transformer if I tinkered with the record player, but in the day they wouldn't have done that.

[William]

I have a RCA radio with a similar chassis, it was a very good playing radio but now I can barely get one station. It too has a phono input and when I tried it with my 45 player it did not sound good. Can't remember if it was a hum or just weak sounding.

Bill

[electra225]

This radio has a huge loop antenna on it, but it is fairly directional. I don't know how radios "get out" of alignment, and why they seem to do that suddenly. It was playing just fine. I try to run each radio in rotation so they all run once a month. There is always at least one that needs tweaking....

[TC Chris]

I I wonder how a hot chassis radio works with a 45 rpm record player accessory. I would think the tone arm could be hot and there might be a hum issue. I'd probably run the radio on an isolation transformer if I tinkered with the record player, but in the day they wouldn't have done that.

My little mono "suitcase portable" RCA 9-EMP-21H record player increases the risk by using a steel case. You're only one paper capacitor away from disaster.

And don't be fooled by the "Golden Throat" jargon. The little portable has the same throat but via a 4" speaker. C'mon now.... Somebody pointed out that it meant that it was engineered for very limited frequency response, although the term implies otherwise.

Chris Campbell

[electra225]

None of my efforts to get to the bottom of the fading have been successful. This thing goes like a house on fire, until it fades. Then I lose about half the stations and the strong ones come in weakly. Sometimes, if I wiggle the 12BA6 IF amp tube, the audio comes back. I have cleaned everything I can see to clean, some of them several times. It acts to me like a bad connection someplace.

[William]

Can you say GE Trimline buzz?It is very aggravating when something is either intermittent or you can't find the why!

Bill

[electra225]

I MAY have fixed it. (I hope that didn't jinx me....) I subbed the 12BA6 IF amp tube. I gave the tube socket a huge squirt of PB BLaster. It played for a couple of hours and didn't fade. I don't have the oscillator tracking set right yet. The instructions say to do the alignment procedure more than once. That may be good advice....