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Old 2nd Mar 2015, 4:50 pm   #133
mark pirate
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Join Date: Mar 2008
Location: Worthing, West Sussex, UK
Posts: 5,185
Default Re: Marconiphone VRC74DA

Hi David, Yes I do have a scope, It certainly is worth checking.

Quote:
As mentioned earlier the contrast control is in wrong position where it is in the first RF stage. it should be the RF gain control and the contrast control should be further on in the vision RF stages.
It is a truly horrible design, what were they thinking?
Worse still is the focus arrangement varying the EHT!
In fact all the presets controls interact with each other, making adjustment a real pain.

I am in the process of connecting the chassis to the CRT in the HMV 2811, so this will be a good test of the chassis and the tube.
In a way I am hoping the CRT in the HMV is low, as I won't have to restore another 1807A chassis set!

Mark
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