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Old 29th Feb 2020, 2:54 pm   #3
Vectamart's Avatar
Join Date: Feb 2007
Location: Ventnor, Isle of Wight, UK.
Posts: 141
Default Re: Pye VT4 - no EHT

Originally Posted by high_vacuum_house View Post
Good afternoon,
I presume the EY51 heater is lit, the valve hasnít lost its emission or there is a failure in the EY51 heater winding on the LOPT. I would check all these things first as these would cause no DC output from the cathode of the EY51.

Christopher Capener
I did change the EY51 but cannot see any illumination from its heater. I am tempted to try substituting the EY51 with a solid state device such as a TV11 stick or similar. I am still baffled by the smallness of the sparks at the top caps of the PY and PL valves - or maybe this is normal for these very old sets? Perhaps I am too used to seeing the bigger sparks on later sets e.g. 1960s/70s.
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