zenith porthole question

[old_coot88]

Sorry to be a fuddyduddy, but the 260, with sensitivity of 20,000 ohms/volt, will impose a loading of 5 megohms when on the 250V scale (250X20,000=5 meg.).
The only time loading would be a problem with the 260 is in very high impedance circuitry.

In the old days meters typically had sensitivity of 1000 ohms/V, 5000 ohms/V. etc. Those could cause signifigant loading errors.

[stusnyder]

Ok got the simpson 260 out and checked.

5u4g pin 2 420v should be 382v
5y3 pin 2 220v should be 187
6bf5 pin 6 105v should be 97

The simpson says my line voltage is 125v

Hooked up the variac and dialed in input voltage to 105 volts. At that voltage I get correct readings, but picture is about the same. The top half of the picture just fades away to nothing.

[stusnyder]

Finally got some progress on this set. I injected a IF signal on the 4th IF tube and I got a decent test pattern. Backed up to the 3rd IF tube and got the half picture. So the problem is before the 4th IF stage. I checked the resistors in the whole IF stage and all the 470 ohms were way out of tolerance, some 200 ohms or more. Replaced them, but still no change.
I also injected a video signal at the video amp and got a decent pic.
The IF section got lots of "dogbone" capacitors. Should I be looking at those, or do I have to search before the IF stage?
Also my voltages are running 30 volts high on the IF stages.