Hi All,
I have been hunting for a tube for a HMV TV for a while now. See the thread
https://www.vintage-radio.net/forum/...ad.php?t=63808
It is now in place after re-caping the waxies and the electrolytics. I brought it up slowly on the Variac and the HT supplies are fine. There is a healthy amount of static from the speaker and the line whistle is present. It is an Australian set, so although it is 1959 it is 625 line.
All tranformers/chokes measure reasonably including the LOPT.
I have a 2-3mm spark from the 1S2 (DY86) but no life from the tube.
The boost voltage shown in the circuit below is low at 375V instead of 650V.
All the valves in the EHT section are NOS. I haven't yet replaced the disc ceramic C86, 150pF across the LOPT.
Any thoughts on how to test\check if the tube is OK and the low boost voltage would be apprectiated.
regards
Craig