Stewart Warner 11-6u BUZZING.. ?? HELP???

10/26/2010 9:27:11 PMJesse

Hi all,
After replacing ALL OF THE CAPS in this radio it has a unreal BUZZING sound.. Not so much like filter caps, but kinda the same.. Radio recieves stations but it just buzzes.. Nothing on around the radio to cause interference, also when volume control is turned it does not increase in vol, just same BUZZING.. Help me please figure out what to look for?

10/26/2010 10:07:45 PMEdd

Sir Jessee. . . . .
Do this schematic be the right series ?

http://www.nostalgiaair.org/PagesByModel/170/M0020170.pdf
We'uns thinks that you " mis-warred" sumpin' . . . . . and you'se gots to figgers out THOSE types of problems yourselfs.
Now:
Would you give us the percentage of the "undesirable" level, as being compared to the radio stations audio being tuned in , and is it different on a stronger or a weaker station ?

Go to the 6F6 output and use a pocket size mini screwdrivers blade to short the 1st grid to the cathode and see if that offending noise, IN ADDITION to the received station audio, then disappears.
We KNOWS that the station audio will disappear but if the offending noise remains, its vewy likely to be in the AF output stage or else being introduced in from the units power supply.

Try the same shorting out with the 6SQ7, and in its case you can just short across its item #10 1st gridamus ree-sistor.

73's de Edd

:Hi all,
: After replacing ALL OF THE CAPS in this radio it has a unreal BUZZING sound.. Not so much like filter caps, but kinda the same.. Radio recieves stations but it just buzzes.. Nothing on around the radio to cause interference, also when volume control is turned it does not increase in vol, just same BUZZING.. Help me please figure out what to look for?
:

10/27/2010 2:29:33 AMWarren

Have to go with Edd on this. You may have made an error replacing the capacitors. With your schematic look over the capacitor connections around the detector AF tube and audio output tube. Go by the pin numbers point to point. The capacitor that connects to the center lug of the volume control. is that going to the grid of the detector tube?

10/27/2010 3:04:40 PMRich in Kansas

Don't know much so take this as comments/questions. If I understand you right the noise stays the same even when the volume control is turned down. Would this not mean the problem is in the power supply or audio after the volume control? Isn't most RF interference effected by volume control? I've been trying to learn about interference as I receive noise on the lower end of AM band on all radios in house. Reminds me of florescent noise. Does any other radio get the noise? Do you get the noise in the middle of the night? I do. (ok I don't sleep well always). But one weekend mine went away but was back Monday morning. I suspect a close neighbor. Anyhow checking all capacitors were correct and good solder connection would be where I would start. Then I would wonder if one of the new ones were bad or wired wrong. But again, I don't know much.

10/27/2010 6:12:48 PMJesse

:Don't know much so take this as comments/questions. If I understand you right the noise stays the same even when the volume control is turned down. Would this not mean the problem is in the power supply or audio after the volume control? Isn't most RF interference effected by volume control? I've been trying to learn about interference as I receive noise on the lower end of AM band on all radios in house. Reminds me of florescent noise. Does any other radio get the noise? Do you get the noise in the middle of the night? I do. (ok I don't sleep well always). But one weekend mine went away but was back Monday morning. I suspect a close neighbor. Anyhow checking all capacitors were correct and good solder connection would be where I would start. Then I would wonder if one of the new ones were bad or wired wrong. But again, I don't know much.
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::Hi all,
:: After replacing ALL OF THE CAPS in this radio it has a unreal BUZZING sound.. Not so much like filter caps, but kinda the same.. Radio recieves stations but it just buzzes.. Nothing on around the radio to cause interference, also when volume control is turned it does not increase in vol, just same BUZZING.. Help me please figure out what to look for?
::
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