Hi All

Thanks for your comments.

Nichrome wire:  Quite a few years ago I replaced the original parasitic suppressors in a friend's SB-220 linear with an updated set from Rich Measures using Nichrome wire and silver solder.    I had some solder left over but looking through the “pile” I can no longer find it.

Welding:   I can check into that but not sure about local availability.


T-202 (Asked by Ray F)  –  I will answer in a different thread.

I have to ask myself if I'm making a mountain out of a mole-hill.

The TBW was originally powered by an 800 Hz gas generator so a wide range of filament adjustment was necessary.

My TBW will be powered off of 120 VAC house power which is a lot more stable, so the range of adjustment isn't going to be that much.      The Filament Rheostat is two of those pots mechanically linked together.    Each is 12 ohms,  so the full adjustment range is about 2 to 24 ohms.  

I was toying with the idea of just bypassing the one pot and using a single pot that will give me 2 to 12 ohms adjustment.    That might be enough in today's world.

Also,  I probably don't even need to use the adjustment!    I will be powering the 500V and all filament transformers from 120 VAC, and the output will probably be close enough to what is required that it won't matter.   I'd like to use the Filament Adjustment as that's what was done in the field.

As someone suggested,  I can always use a fixed resistor in series if needed.

73 Mark K3MSB