View Single Post
Old 1st Mar 2020, 10:39 am   #8
Heatercathodeshort's Avatar
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 7,804
Default Re: Pye VT4 - no EHT

The CRT is a Mullard MW36-24/44. It is aquadag coated and does not require a Visconol. The scan coils go S/C frame to line due to Cellophane insulation between the windings breaking down. Later trouble free coils use Polythene.
They can be disconnected for a test noting that a S/C in the screened wire may also cause problems.
These early rectangular Mullard tubes suffered from inter electrode shorts usually between the A1 and grid causing heavy EHT drain. They can be rewired as triodes but let's not go there until proven! John.

Last edited by Heatercathodeshort; 1st Mar 2020 at 10:44 am.
Heatercathodeshort is offline