Ctc-16

[Charlie]

Yeah I'd cut them close to the tranny, too. Sometimes they give you just barely enough to work with.

Keeping our fingers cross!

[DaveWM]

the plan is to spend some quality time on it tonight, prelim checks show the new one is not shorted so I am pretty sure I have a correct diagnosis.

I wonder if it spontaniously shorted or if there was some defect in the vert circuit thay could have caused a short....

if that was to happen I assume there would have been a spike in current. I think i will double check the vert output tube before firing it up. look for shorts etc...

[DaveWM]

hmmm looks like that short 9 pin fat tube is the vert output. It is the one with the leaky 50uf cap (replaced it) if that was a cathode bypass, then the leak may have reduced the bias and caused the tube to pull too much current thru the load (primary of the vert trans) of course I dont think I have the right tube tester for THAT tube

yep thats it a 6GF7 dual triode, and that was a cathod bypass cap. Oh well, I can wire it up, but I think I will hold off power up until I can get that tube checked for shorts, prob ok but I jsut would hate to toast the new tranny.

[DaveWM]

sams and RCA service man both show about -55v bias on the vert osc output grid, of course they show diff voltages for the grid and cathode but both net to about -55.

The sams shows a 38ma current thru the cathode, no way to read that directly but I guess I could determine it based on the V drop across the cathode resistor..


hmmm scratch that not that simple, I was reading something wrong. This would be a nice time to have a test socket that you could jumper each pin on or off.
not a tube extender but a tube extender that you could make/break the pins for current readings. I dont know if such a think exist.