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Travellingwave · 21st Feb 2021, 10:47 am

So I’ve checked out the contrast control and it seems to be doing what it should. The pot is fine and adjusting it controls the voltage on the cathode of V1/V2 as it presumably should.

I found I can reduce the contrast and then if I adjust the horizontal hold (I think , the left hand top knob on the front) I can get it to lock in ok , but raster shrinks and focus gets worse.

Judging from the increase in corona hiss as I reduce the brightness I recon the EHT is dropping with increased beam current. At the moment I still have my string of IN4007s dangling at 8kv . I have a new EY51 and PL81 on order, anythink else I should be checking?

21st Feb 2021, 10:47 am	#126
Travellingwave Pentode Join Date: Jan 2021 Location: York, North Yorkshire, UK Posts: 155	Re: My first telly TV22 So I’ve checked out the contrast control and it seems to be doing what it should. The pot is fine and adjusting it controls the voltage on the cathode of V1/V2 as it presumably should. I found I can reduce the contrast and then if I adjust the horizontal hold (I think , the left hand top knob on the front) I can get it to lock in ok , but raster shrinks and focus gets worse. Judging from the increase in corona hiss as I reduce the brightness I recon the EHT is dropping with increased beam current. At the moment I still have my string of IN4007s dangling at 8kv . I have a new EY51 and PL81 on order, anythink else I should be checking?