UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - GEC 2028 restoration

Mike Phelan · 29th Dec 2006, 5:02 pm

Dr W
Is both the frame and line sync weak?
The dual diode block is a pair of silicon diodes, so 1N4007s are fine, albeit a bit of overkill!

Have you a 'scope?

The colour beacon works from the killer, by rectifying the 7.8KHz ident signal, so will come on if there is colour present.

We may need a circuit to help you, although others may have better memories than me! I recall something like a 47k feeding line pulses to the aforementioned diode? Has it fried up?

29th Dec 2006, 5:02 pm	#3
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: GEC 2028 Restoration - Advice with Sync Fault Dr W Is both the frame and line sync weak? The dual diode block is a pair of silicon diodes, so 1N4007s are fine, albeit a bit of overkill! Have you a 'scope? The colour beacon works from the killer, by rectifying the 7.8KHz ident signal, so will come on if there is colour present. We may need a circuit to help you, although others may have better memories than me! I recall something like a 47k feeding line pulses to the aforementioned diode? Has it fried up? __________________ Mike.