10-02-2014, 07:18 PM
Started on GE M -65( I believe this is identical to RCA 221) and cannot get any volume control. I replaced electrolytics and all other caps.
The pot that was in there I believe is not the right one. According to what I see on the schematic, I need a tapped pot. I cannot find the value of the tap, I have a 250,000 k pot that has a 125,000 k tap. don't know if this is correct. Gave it a try-- medium volume, no control. Found that a 2A7 was in the place of the 2B7, put 2B7 in and volume went down but still no control (AVC here?). Am currently checking resistors and have replaced a few out of spec ones, still working on that angle, the resistor board is next. Also found 2A5 to be very weak, ordered one. Tone control was cleaned and does work.
Any ideas? Last four pages of attachment are for this radio.
The pot that was in there I believe is not the right one. According to what I see on the schematic, I need a tapped pot. I cannot find the value of the tap, I have a 250,000 k pot that has a 125,000 k tap. don't know if this is correct. Gave it a try-- medium volume, no control. Found that a 2A7 was in the place of the 2B7, put 2B7 in and volume went down but still no control (AVC here?). Am currently checking resistors and have replaced a few out of spec ones, still working on that angle, the resistor board is next. Also found 2A5 to be very weak, ordered one. Tone control was cleaned and does work.
Any ideas? Last four pages of attachment are for this radio.
