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

slidertogrid · 18th Jan 2020, 7:56 pm

From my experience any hum on the LT line of a Transistorised mono portable results in a hum bar or large 'Kink' in the picture travelling up the picture causing the frame to roll when it reaches the top of the screen.
I still think the fault lies with the line speed being off rather than a frame fault.
Can you resolve a line locked picture or are there many pictures side by side when you adjust the line hold?
Have you checked the discriminator diodes? I would try to get the line speed right first and then see if you still have low picture height.
I don't profess to be an expert just my thoughts....
Rich.

18th Jan 2020, 7:56 pm	#41
slidertogrid Octode Join Date: Apr 2005 Location: Peterborough, Cambridgeshire, UK. Posts: 1,898	Re: GEC Junior fineline picture problem. From my experience any hum on the LT line of a Transistorised mono portable results in a hum bar or large 'Kink' in the picture travelling up the picture causing the frame to roll when it reaches the top of the screen. I still think the fault lies with the line speed being off rather than a frame fault. Can you resolve a line locked picture or are there many pictures side by side when you adjust the line hold? Have you checked the discriminator diodes? I would try to get the line speed right first and then see if you still have low picture height. I don't profess to be an expert just my thoughts.... Rich.