rca bta1r

[w5tmg]

im having trouble with the 6146 buffer. i made measurements and everything checks out good except the bias on the tube. its suppose to be -60 and its reading -20, ive got it tapped on the inductor at pos. 7 and it seems like its got the best results, but still the plate is to high and the grid is a little low. my question is if i have to pull the osscilator to check the plate choke on the amp tube, and the 5733uuf cap, what does that certail, and does anyone think that im on the right track...? thnxs

[W4NEQ]

I am only vaguely familiar with the transmitter, having maintained one about 1979.  I am assuming you are referring to -20 vs -80 negative bias voltage on the 6146 driver stage.   And the "plate is too high" means too much 6146 plate current.

IF that is the case I would take a close look at how the 6146 gets it's negative grid bias, and possibly the drive level coming from the previous stage.  I'm not clear on why you would inspect the plate choke.

Chris

 

[w5tmg]

thnxs, the reason for thinking about the plate choke is because it is in the stage before it, coming from the 5763 amp tube... just thoughts out of the box...probably not it...