model 20 hum (detector circuit?)

Register

Guest Join Us

Hello Guest,

Please feel free to join us!
There are many more parts of the Phorum that only members can see.

Thread Rating:

1 Vote(s) - 5 Average
1
2
3
4
5

Linear Mode

model 20 hum (detector circuit?)

Steve Davis
Phorum Expert

Posts: 1,397
Threads: 69
Joined: Oct 2007
City: Linn Creek, MO

#2

10-19-2015, 02:40 PM

Could there be a bad connection where a ground lug is riveted to the chassis? The thing that jumps out at me is the cathode of the 27. If you are using the chassis as the reference, the 27 cathode should read zero volts. If you are using point "B" (the center tap of the HV winding) as the reference, it should read about 8 volts.

I would use a clip lead connected to a good chassis ground and jumper every ground connection in the chassis, starting with the cathode of the 27.

Steve

M R Radios C M Tubes

Find

« Next Oldest | Next Newest »

Messages In This Thread

model 20 hum (detector circuit?) - by Tubesforme - 10-19-2015, 12:11 PM

RE: model 20 hum (detector circuit?) - by Steve Davis - 10-19-2015, 02:40 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-19-2015, 05:23 PM

RE: model 20 hum (detector circuit?) - by Steve Davis - 10-19-2015, 06:03 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-20-2015, 09:01 AM

RE: model 20 hum (detector circuit?) - by mikethedruid - 10-24-2015, 06:04 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-24-2015, 08:24 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-27-2015, 02:58 PM

RE: model 20 hum (detector circuit?) - by Alan Douglas - 10-24-2015, 06:23 PM

RE: model 20 hum (detector circuit?) - by mikethedruid - 10-24-2015, 10:48 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-29-2015, 05:21 PM

RE: model 20 hum (detector circuit?) - by Steve Davis - 10-24-2015, 11:01 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-24-2015, 11:46 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-28-2015, 07:14 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-30-2015, 06:30 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-25-2015, 09:57 AM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-25-2015, 11:40 AM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-25-2015, 10:39 AM

RE: model 20 hum (detector circuit?) - by Kenneth F. Besso Jr. - 10-25-2015, 07:01 PM

RE: model 20 hum (detector circuit?) - by morzh - 10-25-2015, 10:08 PM

RE: model 20 hum (detector circuit?) - by Steve Davis - 10-26-2015, 07:38 AM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 09:18 AM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-26-2015, 11:14 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 09:34 AM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-26-2015, 10:24 AM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-26-2015, 11:12 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-27-2015, 07:43 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-27-2015, 10:38 PM

RE: model 20 hum (detector circuit?) - by Steve Davis - 10-27-2015, 11:25 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-28-2015, 12:12 PM

RE: model 20 hum (detector circuit?) - by Ron Ramirez - 10-28-2015, 01:34 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-28-2015, 07:07 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-28-2015, 10:52 AM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-28-2015, 12:08 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-29-2015, 06:50 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-28-2015, 02:36 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-28-2015, 07:03 PM

RE: model 20 hum (detector circuit?) - by Ron Ramirez - 10-28-2015, 08:10 PM

RE: model 20 hum (detector circuit?) - by radiohenry - 10-29-2015, 06:31 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-29-2015, 06:44 PM

RE: model 20 hum (detector circuit?) - by LASJayhawk - 10-29-2015, 06:57 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-29-2015, 09:10 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-30-2015, 06:21 PM

RE: model 20 hum (detector circuit?) - by LASJayhawk - 10-29-2015, 09:36 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-30-2015, 12:28 PM

RE: model 20 hum (detector circuit?) - by LASJayhawk - 10-30-2015, 02:29 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-30-2015, 02:34 PM

RE: model 20 hum (detector circuit?) - by klondike98 - 10-30-2015, 03:24 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-30-2015, 05:13 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-30-2015, 06:04 PM

RE: model 20 hum (detector circuit?) - by OZ4 - 10-31-2015, 09:40 AM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-31-2015, 01:06 PM

RE: model 20 hum (detector circuit?) - by Ron Ramirez - 11-08-2015, 09:28 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 11-09-2015, 07:11 PM

RE: Low continual hum in model 21 - by Steve Davis - 10-23-2015, 09:34 PM

RE: Low continual hum in model 21 - by Tubesforme - 10-23-2015, 10:19 PM

RE: Low continual hum in model 21 - by Steve Davis - 10-23-2015, 11:01 PM

RE: model 20 hum (detector circuit?) - by Tubesforme - 10-24-2015, 05:50 PM

Need correct voltages for det and af model 20 - by Tubesforme - 11-07-2015, 04:54 PM

RE: Need correct voltages for det and af model 20 - by morzh - 11-08-2015, 11:09 AM

View a Printable Version

Users browsing this thread: 3 Guest(s)