UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

steve.seven · 6th Jun 2020, 5:37 pm

Hi Edward,

Just had a similar issue with my RP37A, very annoying rustling noise with the volume control at minimum setting.

Found the problem to be a poor contact of the wiper on the pre set mid point variable pot RV3.

After moving the wiper back and forth and cleaning the track with Servisol switch cleaner problem solved.

If you need to reset the mid point setting you need to adjust RV3 to obtain a reading of 8.9 Volts measured at the junction of R14 & R15 on the A205 AF amplifier board, this figure need to be set with a supply input voltage of 18.00 Volts.

Hope this may be of help to you.
Regards,
Steve.

6th Jun 2020, 5:37 pm	#11
steve.seven Pentode Join Date: May 2006 Location: Stroud, Gloucestershire, UK. Posts: 211	Re: HACKER VHF "Herald" RP37A Hi Edward, Just had a similar issue with my RP37A, very annoying rustling noise with the volume control at minimum setting. Found the problem to be a poor contact of the wiper on the pre set mid point variable pot RV3. After moving the wiper back and forth and cleaning the track with Servisol switch cleaner problem solved. If you need to reset the mid point setting you need to adjust RV3 to obtain a reading of 8.9 Volts measured at the junction of R14 & R15 on the A205 AF amplifier board, this figure need to be set with a supply input voltage of 18.00 Volts. Hope this may be of help to you. Regards, Steve.