Howdy,
I've been troubleshooting an SB200 and have gotten exactly
nowhere. Measured operating conditions are:
Plate voltage = 2100 indicated on front panel meter
(I've measured 350 VDC +/- 10% across each filter cap)
there is continuity between p.s. and plates (no open choke)
Bias (measured between grid and cathode) = -125 VDC in standby,
-2 VDC keyed
Idle current = 20 Ma indicated
Plate current = 100 Ma with 100 Watts drive
Power output = 100 Watts max on any band
Input VSWR between 2 and 3:1 depending on band
Filament voltage = 6.31 VAC (center tap is grounded)
All components check O.K.
I get the same results with a second set of 572Bs
Does anyone have any suggestions?
73, and Thanks
Bob, W5AH
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