Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
One terminal of the volume control should be grounded. Is it?
The center terminal (wiper arm) of the volume control passes through a bakelite block capacitor, part (27) on the earlier 89-19 schematic, part (26) on the later 89-123 schematic. This bakelite block contains one .01 uF capacitor. The AF signal is then fed from there to the grid cap of the Type 75 tube.
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Ron Ramirez
Ferdinand IN
Thanks for info! Checked it all out and everything is as you said it should be. Bakelite block was a 3903-AB vice 3903-SU in Riders schematic. They are hooked up different but both .01. 3903-AB only has 3 terminals and the cap is hooked up to the middle 2. When I rebuilt this block the wiring I unsoldered was original. It was hooked back up the same way and the old cap taken out from the 2 middle terminals was original. Maybe I just have a pot that is bad at the lower end. It seems to check OK. I have a friend that told me don't work on old radios when you are tired. Did it once and had to go back and fix my mistakes. I work full time so this radio hobby is mainly for days off and weekends. You can't know how many times I,ve had restorers say they hate to work on Philcos, but if you take your time the end result is sweet. Got an old Clarostat 350K pot at work today so may jumper that in to see if it works OK. Again thanks for the info-Kenny Kidd