Strange issue with Telefunken VR 520 - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Maarten · 30th Sep 2025, 11:09 pm

It never hurts to try, but it makes sense that it doesn't resolve the problem. Switching to the video channel only affects the time constant for horizontal synchronisation. It doesn't affect anything in the PAL decoder where the issue is more likely to be. Either with the decoder or with the signal, that is.

Welsh Anorak · 1st Oct 2025, 7:47 am

I would still be tempted to give the line hold control a slight tweak - ISTR having this fault in the past.
I assume it's the single-chip decoder?

30th Sep 2025, 11:09 pm	#21
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,775	Re: Strange issue with Telefunken VR 520 It never hurts to try, but it makes sense that it doesn't resolve the problem. Switching to the video channel only affects the time constant for horizontal synchronisation. It doesn't affect anything in the PAL decoder where the issue is more likely to be. Either with the decoder or with the signal, that is.

1st Oct 2025, 7:47 am	#22
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 7,689	Re: Strange issue with Telefunken VR 520 I would still be tempted to give the line hold control a slight tweak - ISTR having this fault in the past. I assume it's the single-chip decoder? __________________ Glyn