02-13-2008, 10:12 PM
hi fellers,i'm having a brain fade tonight,where do i measure b+ in this chassis? and can the last interstage trans be r/c bypassed? pri and sec. are both open,thanks.
02-13-2008, 10:12 PM
02-14-2008, 12:07 AM
philco phan, I believe between the center tap HV secondary and point J on the schematic will give you full B+ available. Center tap to plates for B+ at tubes. B supply not grounded to chassis in this set. PL
02-14-2008, 05:46 PM
The main B+ would be measured between point D and one of the following points: the center tap of the high voltage winding of the power transformer; pin 2 of resistor (26); or pin 2 of the multi-section filter condenser can. Point J carries a lower B+ voltage that has been dropped by the speaker field coil.
If both primary and secondary of interstage transformer (22) are open, then no, one cannot generally convert it to R/C coupling since the secondary is feeding two tubes connected in push-pull. You'll have to replace this transformer with another one.
If both primary and secondary of interstage transformer (22) are open, then no, one cannot generally convert it to R/C coupling since the secondary is feeding two tubes connected in push-pull. You'll have to replace this transformer with another one.
02-15-2008, 11:11 AM
thanks guys,b+ is good,i'll just r/c bypass to one of the 45's to confirm radio is operational until i can find a suitable tranny,phil