So to follow on from the above, other things have been happening as well.
I would like to thank John (Heatercathodeshort) for sending me a very respectable screening can for the Fireball tuner to replace the very rusty one that I had. He also sent a spring which was missing so once the front of the tuner is painted (carefully sand blasted today) I can clean and reassemble the rest of it.
I stocked up on capacitors from the BVWS stall at Harpenden at the weekend. Its a pity that even 630V caps are so small and rather yellow these days! I have been ordering in some of the other values I need for this project. I have also found a range of resistors I am happy with that look ok, so have ordered a good range of these.
I turned my attention to the poor old mains dropper which was looking very sorry for itself- its in two bits
Every section bar one that isn't used on 240V setting was open circuit! I imagine that constant water over the last 30 years may have had something to do with that!
Adding up all the heater voltages gives 137V which means 102 V has to be got rid of by the dropper- that's 30W
Plus whatever the HT section needs to drop as well so the poor thing is going to get very hot and bothered. It doesn't help that it has a solid state rectifier for the HT- a PY32 would have added another 30 odd volts to the heater chain thus reducing the dissipation of the dropper.
It's a pity there wasn't a range of valves with lower current (say 100ma) and higher voltage heaters available to manufacturers at the time. (Or was there?) That would have eased the load on the dropper.
So if anyone has a spare dropper, I would be very grateful for it
John (HCS) said that even in the early 60's, they were difficult to find and suggested I make one out of RS 'polo mint' power resistors!! Granted they would be period- I regularly used to see them in sets I played with as a kid.
However, I'll put up a wanted post and see if anyone can come up with one or something similar.
I think that's about it for now; should be more to report later in the week.
Cheers Nick