UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Restoring a CP110, tube life after regeneration?

3CX15000A7 · 11th May 2021, 3:24 pm

Hi all,

In meanwhile I did a nearly full recap on the CP110 set and soldered the whole tube neck board again! (it was full of bad joints)

I still struggle to get a OK/good picture, with a lot of odd picture faults (ghosting, moire, linearity issues etc.)

So I decided to go back to the basic, the PSU and line stage. The 12/15V/32V seems OK, but I found some odd behaviour in the line stage.

Measuring at the base of the Hdrive transistor (T7630) I get some strange ringing at the square wave that shouldn't there according to the service manual. I disconnected the H deflection coil to check the stage around TDA2579 and it dissapeared (I got a nearly perfect square wave).

Any ideas where the ringing comes from? Can it be the diodes D6610/D6609? Wondering if this causes also the hot running LOPT . .

11th May 2021, 3:24 pm	#12
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Restoring a CP110, tube life after regeneration? Hi all, In meanwhile I did a nearly full recap on the CP110 set and soldered the whole tube neck board again! (it was full of bad joints) I still struggle to get a OK/good picture, with a lot of odd picture faults (ghosting, moire, linearity issues etc.) So I decided to go back to the basic, the PSU and line stage. The 12/15V/32V seems OK, but I found some odd behaviour in the line stage. Measuring at the base of the Hdrive transistor (T7630) I get some strange ringing at the square wave that shouldn't there according to the service manual. I disconnected the H deflection coil to check the stage around TDA2579 and it dissapeared (I got a nearly perfect square wave). Any ideas where the ringing comes from? Can it be the diodes D6610/D6609? Wondering if this causes also the hot running LOPT . . Attached Thumbnails