[Milsurplus] TBW transmitter

[Ray Fantini]

I am using a 12.6 volt 4 amp center tap transformer for the two 837 tubes, have had no issues with the drop by the VFO decoupling chokes. although the filament is reduced the tube works fine. Have a center tap 10 volt 8 amp transformer for the 803. Its important to remember that the transformers for the 803 center tap is the return to ground for the PA tube! originally I was going to instal the plate current meter in that leg to ground but if you do that then you will see the screen current added to the over all reading so ended up keeping it in the low side of the plate supply. the original filament rheostat is used to control the primary of the PA tube transformer only and that is set for a output of about 9.5 volts.  think the 837 in the VFO runs at around 10.5 to 11.0 volts after the chokes and the IA gets full 12.5, I always try to use reduced filament voltage although 837 and 803 tubes have not been a problem to obtain. The last couple 803 I bought I did not pay more then $20 each and they worked good on 40 and 80 meters and have yet to damage one, the weird thing about that transmitter is in the tune mode they still apply full screen and remove the plate voltage but that has not appeared to damage the tube I have been using yet.
Ray Fantini KA3EKH