the problem is audio distortion at low to half volume; like talking through water. I have replaced bad tubes, capacitors, and the audio output xfmr. the xfmr was from a similar speaker. The volume control assy seems to be ok. Ctrl grid bias on output tubes is different. The audio resp is a little tinny at half vol and above. Any suggestions will be greately appreciated, thx, Allan
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:I am working on my Philco model 38-4 am radio with push/pull 6f6 output, 6k5 audio and 6j5 det/avc.
:the problem is audio distortion at low to half volume; like talking through water. I have replaced bad tubes, capacitors, and the audio output xfmr. the xfmr was from a similar speaker. The volume control assy seems to be ok. Ctrl grid bias on output tubes is different. The audio resp is a little tinny at half vol and above. Any suggestions will be greately appreciated, thx, Allan
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: : : :  : : : : : : : :Sir Allan St Marie . . . . . : : :Initial probing queries : : : :Ctrl grid bias on output tubes is different. : : : :With a DC voltage positive probe stabbed into chassis ground, what does the other probe read as the negative grid bias present for the 1st grid voltage of the 6K5 driver and the 6F6 AF outputs tubes. : : : : : :No cone dragging on the speaker . . . is there ? : : :As per the "under water " sound effect, any chance of a copper sulfate devoured antenna coil ? : : : : :73's de Edd : : : : : I got a new shadow. I had to get rid of the other one . . . It wasn't doing what I was doing. : : : :  : : : |
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::I am working on my Philco model 38-4 am radio with push/pull 6f6 output, 6k5 audio and 6j5 det/avc.
::the problem is audio distortion at low to half volume; like talking through water. I have replaced bad tubes, capacitors, and the audio output xfmr. the xfmr was from a similar speaker. The volume control assy seems to be ok. Ctrl grid bias on output tubes is different. The audio resp is a little tinny at half vol and above. Any suggestions will be greately appreciated, thx, Allan
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