25-04-2017, 03:45 PM
The cathode of the triode section is at about 60V because it's being used as a phase splitter. The cathode of the pentode is close to 0V. In its original TV application it would have been very close to the bottom of the heater chain. Just about any valve will take 60V between H and K.
Looking at the circuit (pp100-101 of R&TVS 1955/6) it looks like Ferguson provided an overwind on the heater winding to power the PCF80 heater. All the other valves are 6.3V.
Looking at the circuit (pp100-101 of R&TVS 1955/6) it looks like Ferguson provided an overwind on the heater winding to power the PCF80 heater. All the other valves are 6.3V.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
