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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Apr 2008 Posts: 44 Wrench Fetcher | | Wrench Fetcher Joined: Apr 2008 Posts: 44 | Hello!
So I got my radio in a few weeks ago, and have been fiddling with it in my spare time. The problem is, it's dead. I've tested the driver, it's fine. Radio powers up, vibrator hums, dial light comes on, and heaters on the tubes get nice and hot. Still nothing.
Should I go disassemble and start replacing capacitors, like it says in the tech tip? If so, what do I order?
Thanks for the help!
Cheers, Matt | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | It is quite likely that the vibrator is not functioning correctly. It neesds to be working properly before the radio will do anything. On the other hand, if it was working the power supply was working, you might be unlucky enough to have old capacitors do damage to some of the circuits. I would remove the back and if the capacitors are the original yellow ones covered in wax, I would replace all of them before giving it any more power. This is the way I always proceed with my radios. | | | | | Joined: Apr 2008 Posts: 44 Wrench Fetcher | | Wrench Fetcher Joined: Apr 2008 Posts: 44 | It is definitely all original, still has the paper capacitors. I proceeded according to the how to on this site, and first powered it up without the vibrator. If the vibrator hums and the tube heaters warm, is it still possible to have a bad vibrator?
Also, what are the best sources for these components?
Thanks,
-Matt | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | This place sells tubes and electronic vibrators and more: Antique Elactronic Supply This is where I buy my capacitors: Capacitors resistors and Schematics The vibrator has two sets of contacts and they both must be working in order for the power supply to work. It can buzz on the one set. Fred | | | | | Joined: Nov 2000 Posts: 171 Shop Shark | | Shop Shark Joined: Nov 2000 Posts: 171 | Pull that cover over the power supply, most likely you'll find the buffer had gotten hot and melted the wax out of it ,you can cut one side out and put power back to the radio, if it has an original 0Z4 ,rectifier, glass it will glow purple,if it's a metal 0Z4 ,you can see it glow purple on the underside of the tube sockets You got to get your "B" voltage up first, between 250 - 300 volts, measure off the filter. Then touch out put grid,volume control good spot, with a wet finger and see if you get a noise[ I'm not kidding about the wet finger!} | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | I guess that if you want to troubleshoot, it would be good to see if you have the proper DC voltage at the bottom of the filter can. As Bill said, the higher one is around 250v DC or so. For the grid test, I would suggest using a length of insulated hookup wire about a foot long. Bare a small amount on one end and use touch it to the grid. I wouldn't advise making finger contact anywhere. | | | | | Joined: Nov 2000 Posts: 171 Shop Shark | | Shop Shark Joined: Nov 2000 Posts: 171 | I have a signal generator, I'm assume he dosen't,but you should know what to touch and what not to,stay away from the power supply!touch just the grids Once you get your volage up you trouble shoot from the speaker and work your way to the antenna .Last week I had one of these truck radios with a open OSC. transformer lost the signal in the "IF"stage As a rule these are fairly rugged radios , but I have found all the possible problem one can find in a radio ,with these truck radios, but if it has not been in salt water for years or a bad fire they can be made to play again | | |
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