Rca 9-t-246

[yagosaga]

Hello,

today I have fired up the RCA 9-T-246 for which I asked for the schematics. Steve Kissinger sent me a copy, thank you very much.

After cleaning the set, it was full of asbestos, I reformed the electrolytics and checked the chassis and the tubes for faults. Nothing significant was visible.

When I switched it on with a variac, I could hear no wistle from the line output unit. I checked input signal of the line output tube 6BG6 at the junction R183 and C160 with the scope. The sawtooth should be 40 Vpp, but I only get 30 Vpp. At the grid, there should be -110V, the reading was -100V.

With signal and a readjustment of the ion trap, I got the first light on the screen (see photo). Like I measured before, horizontal width is too small. At pin 5 (6SN7-GT) of the line oscillator, there should be 54V, the reading was 38V. All voltages in the oscillator unit seem too low. Does somebody has a suggestion?

- Eckhard