View Single Post
Old 1st Mar 2020, 11:41 am   #9
Vectamart
Pentode
 
Vectamart's Avatar
 
Join Date: Feb 2007
Location: Ventnor, Isle of Wight, UK.
Posts: 139
Default Re: Pye VT4 - no EHT

The update is that I have substituted the EY51 with a BY187-01 and now have a raster. Brightness looks OK. There is a motorboating noise emanating from the speaker which various according to the frame speed. I have replaced the PY81 with a PY800/81 and the PL81 and the warm-up time has become much shorter, I read somewhere that the original PY81 valves took around 3 minutes to reach full emission.

The new PL82 made no improvement to the frame scan but I suspect that the cathode bypass cap probably need replacement. Now that I have a raster of sorts, I will go right round the set methodically one stage at a time.

Many thanks to all those who have posted comments so far.
Vectamart is offline