I recapped this radio a while back. The problem with this radio is a humming sound and the speaker vibrates with the volume turned all the down. It does play but low bass sounds makes it sound rough.
Thanks for all the great help.

Re-check and make sure the 3 electrolytic caps negative sides are going to the 'floating' negative B+ line, not directly to chassis.

:Re-check and make sure the 3 electrolytic caps negative sides are going to the 'floating' negative B+ line, not directly to chassis.
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I double check an none of the electrolytic capacitors are grounded to the chassis.
Any other suggestions?

Check for bad audio output tube.

:Check for bad audio output tube.
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Just check it 75% no shorts. I'm tracing the hum with a signal tracer backwards from the speaker to the 12SJ7 AF tube. Thanks for the quick response.

::Check for bad audio output tube.
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:Just check it 75% no shorts. I'm tracing the hum with a signal tracer backwards from the speaker to the 12SJ7 AF tube. Thanks for the quick response.
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I think I'm on to something, instead of having a 12SJ7 tube a 12SK7 tube is in the socket. The tube section list a 12SJ7 substitute for a 12SK7 but not a 12SK7 substitute for a 12SJ7.

:::Check for bad audio output tube.
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::Just check it 75% no shorts. I'm tracing the hum with a signal tracer backwards from the speaker to the 12SJ7 AF tube. Thanks for the quick response.

:::Check for bad audio output tube.
:::
::Just check it 75% no shorts. I'm tracing the hum with a signal tracer backwards from the speaker to the 12SJ7 AF tube. Thanks for the quick response.
::
:I think I'm on to something, instead of having a 12SJ7 tube a 12SK7 tube is in the socket. The tube section list a 12SJ7 substitute for a 12SK7 but not a 12SK7 substitute for a 12SJ7.
Never mind Tube section is correct both ways
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You may still have a bad tube. Typical shorts testing will not show a heater-to-cathode "leak". Very common source of low level, persistent hum. Sub a known good tube.

When you recapped, did you change the lead dress in the area of the first audio tube (tube fed by the volume control pot)? This is a high gain stage and if any AC line (say, from the heater circuit) is too close and is running parallel to the tube grid wire, 60 Hz AC can couple over and be amplified independent of the volume control setting.

One way to troubleshoot this is to take a wooden probe (I use a chopstick) and gently move parts/wires around in the vicinity of the first audio amp tube (12SJ7 in your set, I think) while the set is playing, to see if a difference is made.

For the record, not only should heater wires be kept away from the tube grid, they should be run as close to the metal chassis as possible, which will tend to confine the AC field to itself.

:When you recapped, did you change the lead dress in the area of the first audio tube (tube fed by the volume control pot)? This is a high gain stage and if any AC line (say, from the heater circuit) is too close and is running parallel to the tube grid wire, 60 Hz AC can couple over and be amplified independent of the volume control setting.
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:One way to troubleshoot this is to take a wooden probe (I use a chopstick) and gently move parts/wires around in the vicinity of the first audio amp tube (12SJ7 in your set, I think) while the set is playing, to see if a difference is made.
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:For the record, not only should heater wires be kept away from the tube grid, they should be run as close to the metal chassis as possible, which will tend to confine the AC field to itself.
:
With a wood dowel I pushed and prodded wires around and moved and resoldered the electrolytics away from the 12SJ7 (I have a 12SK7 tube in the socket now? Still had a Hum. Then I switch the two 12SK7 tubes around and the humming stopped, but the radio still sounds kind of rough. I'm going to try to find a pair of 12SJ7 and 12SK7 on ebay and see what happens then.

Thanks to everybody . CV thanks for your comment I did noticed the hum fluctuate and ezblah your comment was very interesting about tubes that test good, can be bad.

Just for the heck of it -- reverse the power plug in the wall outlet and see if it makes a difference.

:Just for the heck of it -- reverse the power plug in the wall outlet and see if it makes a difference.
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Reversed tubes, hum equal with plug turned around both ways.

This chassis may depend on tube socket ground rings riveted to the chassis. Solder each ring to the chassis.
This was the cure for many a radio with the same problem.

Regarding the speaker "vibration" :

Clip/unsolder the leads going to the speaker terminals and temporarily clip in a different speaker to see if the "vibration" you mentioned disappears. This will tell you if the problem is mechanical or electronic.

I just did a repair on an H125 and the speaker voice coil was rubbing at all but the lowest volumes causing an annoying raspy vibration sound. Replacing the 4" speaker solved the problem in that case.

The H125 is a very small radio and is not particularly noted for it's fidelity... but the small speaker SHOULD produce nice clear sound.

:Regarding the speaker "vibration" :
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:Clip/unsolder the leads going to the speaker terminals and temporarily clip in a different speaker to see if the "vibration" you mentioned disappears. This will tell you if the problem is mechanical or electronic.
:
:I just did a repair on an H125 and the speaker voice coil was rubbing at all but the lowest volumes causing an annoying raspy vibration sound. Replacing the 4" speaker solved the problem in that case.
:
:The H125 is a very small radio and is not particularly noted for it's fidelity... but the small speaker SHOULD produce nice clear sound.
:
I wanted to replace the speaker at first but I couldn't find a replacement. I found a lead to the the speaker coil had rusted off. I was able to solder a new lead in and make it work. Can you tell me were I can find a replacement if the new tubes I ordered don't fix the problem. Thanks

"Can you tell me were I can find a replacement"

GoTo: http://www.radiodaze.com/product/1098.aspx

: "Can you tell me were I can find a replacement"
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:GoTo: http://www.radiodaze.com/product/1098.aspx
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:I purchased the replacement speaker from radiodaze.
Now I have a new problem, I can hear it play but sounds like a whisper with the volume turned all the way up.

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: Resistance across across output transformer primaries is 340 ohms. Test quickly striking a lead on negative of electrolytic with other end connected at the plate of output tube results in loud burst of static at speaker. Replaced .01 mfd capacitor shunting output transformer. Ohms of output transformer secondary and ground is .8 ohms. I noticed that original speaker voice coil resistance on the schematic states 2.95 ohms. The replacement speaker is 8 ohms, can this be the problem.

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: : : : : : : : : : : : : :Sir Ralph Ceeeeeeeeee . . . . . . : : : :" Now I have a new problem, I can hear it play but sounds like a whisper with the volume turned all the way up." : : :Sounds like to me that your connection scenario betwixt the " new " speaker and its output transformer is open circuit . . . .with you possibly only hearing the "screaming" of the output tansformer laminations . . . but with its audio being, but a mere "whisper" to your ears. : : :For a simple seat of the pants test, merely connect a test lead and its clips to EITHER ONE of the three common connections of the top of the output transformer primary OR the top of the .01 tone capacitor shunting the output transformer primary OR the plate of the audio output tube . . . . whichever is the most convenient to your clip access. : : :Then . . . .and then ! . . . AND THEN ! ! ! . . . . you take the free clip of the test lead and brush it VERY quickly against the common NEGATIVE lead of any of your 3 electrolytics of the set (DC ground). : : :Doing the action , just as QUICKLY, as if you were striking a match. : : :That should result in a VERY loud burst of static coming from the speaker. : : :If still, just the "whisper" . . . . power down and ohm out your connections between the output transformer and the speaker voice coil, suspecting an open circuit. : : :If that is not the problem, be sure that the speaker voice coil to output transformer are not getting grounded by an ALREADY grounded speaker frame connection, as the schematic shows. : : :Lastly, if the set has run at max volume without the speaker connected, the .01 ufd cap shunting across the audio output transformer primary may have dead shorted . . . or the situation may have been exacerbated by your replacing with too low of a peak voltage rating . . . IF you done such . . . . during a recap procedure. : : : :Thasssit . . . . : : : : : : : : :73's de Edd : : : : : : : : :When I was young, my mom called me just about everything . . . . . . except a son-of-a-bitch. : : : : : : : : : : : : : : : : : : :

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::: "Can you tell me were I can find a replacement"
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:::GoTo: http://www.radiodaze.com/product/1098.aspx
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:::I purchased the replacement speaker from radiodaze.
::Now I have a new problem, I can hear it play but sounds like a whisper with the volume turned all the way up.
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I finally figured out what was wrong. Apparently when I was handling the radio while replacing the speaker, I pushed on a capacitor and one of its leads was making contact a lug of the AF 12SJ7 tube. Radio is working fine now. Thanks for the help troubleshooting learned a lot.

:: Resistance across across output transformer primaries is 340 ohms. Test quickly striking a lead on negative of electrolytic with other end connected at the plate of output tube results in loud burst of static at speaker. Replaced .01 mfd capacitor shunting output transformer. Ohms of output transformer secondary and ground is .8 ohms. I noticed that original speaker voice coil resistance on the schematic states 2.95 ohms. The replacement speaker is 8 ohms, can this be the problem.
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:: :: :: :: :: :: :: :: :: :: :: :: :: ::Sir Ralph Ceeeeeeeeee . . . . . . :: :: :: ::" Now I have a new problem, I can hear it play but sounds like a whisper with the volume turned all the way up." :: :: ::Sounds like to me that your connection scenario betwixt the " new " speaker and its output transformer is open circuit . . . .with you possibly only hearing the "screaming" of the output tansformer laminations . . . but with its audio being, but a mere "whisper" to your ears. :: :: ::For a simple seat of the pants test, merely connect a test lead and its clips to EITHER ONE of the three common connections of the top of the output transformer primary OR the top of the .01 tone capacitor shunting the output transformer primary OR the plate of the audio output tube . . . . whichever is the most convenient to your clip access. :: :: ::Then . . . .and then ! . . . AND THEN ! ! ! . . . . you take the free clip of the test lead and brush it VERY quickly against the common NEGATIVE lead of any of your 3 electrolytics of the set (DC ground). :: :: ::Doing the action , just as QUICKLY, as if you were striking a match. :: :: ::That should result in a VERY loud burst of static coming from the speaker. :: :: ::If still, just the "whisper" . . . . power down and ohm out your connections between the output transformer and the speaker voice coil, suspecting an open circuit. :: :: ::If that is not the problem, be sure that the speaker voice coil to output transformer are not getting grounded by an ALREADY grounded speaker frame connection, as the schematic shows. :: :: ::Lastly, if the set has run at max volume without the speaker connected, the .01 ufd cap shunting across the audio output transformer primary may have dead shorted . . . or the situation may have been exacerbated by your replacing with too low of a peak voltage rating . . . IF you done such . . . . during a recap procedure. :: :: :: ::Thasssit . . . . :: :: :: :: :: :: :: :: ::73's de Edd :: :: :: :: :: :: :: :: ::When I was young, my mom called me just about everything . . . . . . except a son-of-a-bitch. :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: ::

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:::: "Can you tell me were I can find a replacement"
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::::GoTo: http://www.radiodaze.com/product/1098.aspx
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::::I purchased the replacement speaker from radiodaze.
:::Now I have a new problem, I can hear it play but sounds like a whisper with the volume turned all the way up.
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