Fourth Vivat PWM Part 3

Paul writes:

Latest photo – I  managed a few more hours today.

Marconi No 1 chart on PWM.

Looking good, but I did a bit of an audit on these PWMs and not 100% good news. This one is indeed the last one to be restored and tested; but, the one on the far right of the stack still needs a ‘shed load’ of caps changing in the waveform part. Looks like I never finished it. Never mind, I bought plenty of caps some time ago.

By the way, the Russian 5R4GY rectifiers shipped directly last year work a treat. I ought to order more and also some of their 6AS7Gs when things are a bit more like normal again. Good valves and good value for money. I’m also now running short of 6AG7s (the metal clad video amplifier valve).

We have no spare picture tubes for the PWMs so it’s ‘wing and a prayer’ time. They’re 10FP4A or equivalent.

Generally, Vivat needs valves for spares as well as on-going restoration – there’s many hundreds in service!

Still a lot to do . . .