Does anyone know radios?

lowell · 02-13-2009, 12:38 AM

I have an RCA 8x71 that has pretty low volume, and no FM. The AM comes in a little but just one or two channels and is still scratchy. So far I have replaced all the tubes and the power bulb. It started out not even turning on.

loudthud · 02-13-2009, 01:18 AM

Check any open style tuning caps for debris shorting them out. The shaft is usually grounded. Many times there is a low resistance coil across the cap so you may have to disconnect everything to check. Check/spray the AM/FM switch.

There is bound to be a forum somewhere for people restoring old radios.

Enzo · 02-13-2009, 04:24 AM

leaky and dried up caps are a lot more of a problem in sensitive radio circuits than they are in guitar amp circuits. I'd expect to change any and all waxy paper caps.

www.tubesandmore.com used to have links and other support for radios, they sell parts to the old radio crowd after all. Ever need an old Philco dial, see them.

Robert M. Martinelli · 02-13-2009, 06:24 AM

+1 on both.

At those frequencies ( especially FM ) it takes very little to lose signal, so checking ALL the caps surely is a good idea, I would check all the resistors too, as you could have one or more which have drifted way off spec....

I would also advise to "renew" all the solder joints, you could have bad/cracked ones around and sometimes they're hard to spot by the naked eye.

Hope this helps

Best regards

Bob

stokes · 02-14-2009, 03:37 PM

Try www.antiqueradios.com/forums The name speaks for itself.

manyprojects · 02-21-2009, 05:48 PM

You can also try the antiques wireless association

manyprojects · 02-21-2009, 05:49 PM

Sorry, that is Antique Wireless Association

02-13-2009, 12:38 AM	#1
lowell Senior Member Join Date: Jun 2007 Posts: 1,128	Does anyone know radios? I have an RCA 8x71 that has pretty low volume, and no FM. The AM comes in a little but just one or two channels and is still scratchy. So far I have replaced all the tubes and the power bulb. It started out not even turning on.

02-13-2009, 04:24 AM	#3
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,360	leaky and dried up caps are a lot more of a problem in sensitive radio circuits than they are in guitar amp circuits. I'd expect to change any and all waxy paper caps. www.tubesandmore.com used to have links and other support for radios, they sell parts to the old radio crowd after all. Ever need an old Philco dial, see them. __________________ Education is what you're left with after you have forgotten what you have learned.

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02-13-2009, 01:18 AM	#2
loudthud Supporting Member Join Date: May 2006 Location: Texas USA Posts: 923	Check any open style tuning caps for debris shorting them out. The shaft is usually grounded. Many times there is a low resistance coil across the cap so you may have to disconnect everything to check. Check/spray the AM/FM switch. There is bound to be a forum somewhere for people restoring old radios.

02-13-2009, 06:24 AM	#4
Robert M. Martinelli Supporting Member Join Date: Jun 2008 Location: Italy Posts: 993	+1 on both. At those frequencies ( especially FM ) it takes very little to lose signal, so checking ALL the caps surely is a good idea, I would check all the resistors too, as you could have one or more which have drifted way off spec.... I would also advise to "renew" all the solder joints, you could have bad/cracked ones around and sometimes they're hard to spot by the naked eye. Hope this helps Best regards Bob

02-14-2009, 03:37 PM	#5
stokes Old Timer Join Date: May 2006 Location: NYC Posts: 1,305	Try www.antiqueradios.com/forums The name speaks for itself.

02-21-2009, 05:48 PM	#6
manyprojects Junior Member Join Date: Feb 2009 Location: Hartwick, NY Posts: 4	You can also try the antiques wireless association

02-21-2009, 05:49 PM	#7
manyprojects Junior Member Join Date: Feb 2009 Location: Hartwick, NY Posts: 4	Sorry, that is Antique Wireless Association

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