a real challange?

[Yamamaya42]

Originally Posted by Kevin Kuehn

Another thought is the tuner and IF sections have a whole slug of 1500pf power supply bypass caps between B+ to ground. If pulling those RF and IF tubes doesn't give results, it's possible you have one or more bypass caps that are leaky. Also if you disconnect one end of R39(Sams 150 ohm) you would free up that 135v supply from the 4th IF stage forward. Something needs to give and it's simply a matter of sniffing it out. The key here is you need to divide and concur to find out what circuit is pulling the voltage down. Forget worrying about your picture quality until you find what is pulling that B+ down.

there are 21 of those little bastards in there.
all still orig, I was hoping they would not be a problem, but if the new 6.750 k bleeder does not bring up the 135v to around where it should be, they are next on the list, might as well get them all, they are cheap enough.
I just hope that the resistors IN the tuner are OK, for I really don't want to go in there or have to take it out to get to them, but with the way that I have found some resistors that were almost 2x over what they should be, I DO wonder...
But finding resistors that far off does not surprise me, given that this thing spent 2/3s of it's life neglected in a dark, dank musty basement in Pennsylvania.
And I know that carbon resistors HATE THAT!

[Kevin Kuehn]

Originally Posted by Yamamaya42

there are 21 of those little bastards in there.
all still orig, I was hoping they would not be a problem, but if the new 6.750 k bleeder does not bring up the 135v to around where it should be, they are next on the list, might as well get them all, they are cheap enough.
I just hope that the resistors IN the tuner are OK, for I really don't want to go in there or have to take it out to get to them, but with the way that I have found some resistors that were almost 2x over what they should be, I DO wonder...
But finding resistors that far off does not surprise me, given that this thing spent 2/3s of it's life neglected in a dark, dank musty basement in Pennsylvania.
And I know that carbon resistors HATE THAT!

How difficult is it to lift that 3 section candohm from the chassis, assuming it's riveted on. Doing so you may see your low resistance section move back closer to 6.750k. If that holds true, then leaving it isolated from the chassis it's likely you'd also see your 107V B+ come closer to 135v, as well as your 265V increase to 275V. It's something you could do while waiting for the replacement resistor to arrive. Keeping in mind the Candohm will heat up much more so than normal when it's physically not being heatsinked to the chassis, so this is only a short test to see if the B+ increases.

The above scenario is all based on my hunch that the one section has burned through the fish paper and is partially shorted to ground. And also requires that there's not a wire physically connecting the Candohm housing to ground.