VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1937 Radio

Ever since I bought my car (or Maxine, as I refer to her) the radio has never worked. I attempted to pull the radio unit, head, and speaker out of the car to send it off to the shop, but couldn't figure out how the dang thing came out. So, before I attempt to disassemble it, I pulled out all of the electrical tubes and found that it looked like some, if not all, are burnt out. I have all the tubes sitting here next to me with the part numbers on them, but don't know where to start shopping for new tubes. Any suggestions?

Another potential problem I see, is that one of the tubes is a FoMoCo part. Can Ford electrical tubes be used in a Chevy? I'm worried about the positive ground in Fords being a problem for these tubes?

Google is your friend. That is just one of almost five million hits when I searched for <car radio tubes>.

Wow, I never thought that the old tubes would be so readily available. Thanks!

I found my "CHEVROLET SUPERHETERODYNE RADIO RECEIVER" instruction manual, and compared the tubes that I pulled from my car to the tubes in the manual, and none of them matched up. How can I tell if the radio in my car is from a 1937 Chevy or from some other car? I don't have a diagram of how everything is laid out to compare it with mine.

It sounds to me like someone "may" have populated your radio with dud tubes. However, you cannot always tell if a tube is dead just by looking unless they are really fried.

Unless someone has replaced the vibrator, that is very likely no good and should be replaced with a modern solid state unit.

Does your radio look like the one in the manual that you have?

If you need tubes, I may be able to help you. I have over 1,000 tubes in my stockpile.

There is a gentleman named Ray ??? on this site. He is the radio expert and I suggest that you contact him. These radios are not DIY projects unless you know what you are doing.

Rich

Tubes cause less than 5% of car radio problems. The other 95% is in the power supply.

Inside the radio on a paper label is the Model Number of your radio (unless someone removed it)or the tube lineup and description of the radio can be used to identify your radio.

Any other technical radio questions, send me a PM.

I think I've found the problem/solution: The model number on the sticker inside the cover is 985284, but the model number on my instruction manual is 985253. The sticker inside the cover matches pretty closely to the tubes I pulled out. The only difference is one calls for a 6J5G and I have a 6J5GT, some others call for the last letter to be a G, but my tubes don't have that last letter. I know "G" means glass bulb and "GT" means glass tubular. Are they interchangeable?

In car radios, YES.

You may wish to contact one of the radio repair men on this forum for help with your radio.

I'm thinking this may be the best approach:

1) Replace vacuum tubes with new ones. Some of the tubes look burnt (like a burnt light bulb) and I can hear rattling when I shake some.

If that doesn't work:

2) Troubleshoot/replace the vibrator. I don't know how much a vibrator costs but hopefully I can determine whether or not mine is faulty.

If THAT doesn't work:

3) Figure out how the dang thing comes out and send it in to a professional.

Comments?

1. Stop shaking your tubes. Just because they look burnt, they likely are not burned out. If something is loose, it is toast. A quick and dirty test can be done with an ohm meter. If you let me know what tubes you have, I can tell you what the fillament connections are. If these are not open, it is likely that they are okay. Ray likely has your tubes, I may also and Antique Electronic Supply (along with several other suppliers) certainly has your tubes.

2. The vibrator is DEAD, count on it. They run in the $30 - $55 range. New ones are solid state, no moving parts. If you were to open the can, you would find that the foam that was inside has turned to a yellow tan goop and coated the interior parts.

3. Yes, this is a good idea.

Rich

Ok, online I found the 1948 RCA Receiving Tube Manual, so now I can check continuity of the filaments. I pulled out the vibrator, and it is a solid state vibrator. Can hooking 8.5 volts in the opposite polarity ruin the vibrator? Is there a way to check to see if it is functional?

Don't apply voltage directly to the vibrator, yes, you can fry it. For now, assume it is good. Verify you have the correct tubes in the correct tube socket and that you have at least continuity through the filaments. If so, power it up and see if the tubes light in the circuit. Verify that your antenna is connected and that the speaker is also properly connected. If you don’t have it working by this time, box it up and send it to a PRO.

A little background on me. I do restore antique tube radios, but the only tube car radio I have done is mine. I am NOT a car radio expert, Ray is. Engage him in this exercise and you will be better off in the long run.

Rich

Thanks, Rich!