Admiral Telebar help

[EdKozk2]

Originally Posted by Electronic M

ED, the B&K analyst family can drive a set's flyback directly at the output tube plate lead...I've got a B&K 1077 analyst and have used it that way several times.

HiTom, I figured since he threw in a new flyback that it would be better to check the operation of the horizontal output tubes associated circuits.

[old_coot88]

The Analyst will drive the grid too, right?

[Radiotronman]

Ed,

How did you know those doorknob caps were bad? What symptoms did they cause and were they killing hv? Where did you get replacements?

[EdKozk2]

Originally Posted by Radiotronman

Ed,

How did you know those doorknob caps were bad? What symptoms did they cause and were they killing hv? Where did you get replacements?

The second anode voltage was too low and causing the HV rectifier arc internally. Had close to no HV on the other set also, so I just changed it any way. I replaced the doorknobs with 15kv ceramic disk caps, .001mfd. I had to modify the mount and connections to use the cap on the underside of the chassis. Special attention to lead placement and spacing is required when modifying. You don't want intermittent arcing. Only make this change if your sure about the doorknob. Don't forget that troubles with vertical output transformer can load down the B+ boost voltage too.

[Radiotronman]

I did a continuity check on the hv cable last night and could not get continuity from pin 7 on the hv rectifier socket to the hv button. I did get continuity from pin 4. The cable ties in with a 470k resistor off pin 7. They might have used pin 4, since it's an unused pin as a junction point for the cable and resistor, but shouldn't I have gotten continuity from pin 7, where the other leg of the 470k resistor should attach? I'll take apart again tonight and check this. There was some sloppy repair work on this set before I got it, maybe they hooked something up wrong while repairing. Instead of a 470k resistor in the hv socket, there was two 1meg resistors in parallel (making 500k). I can't imagine that was original from Admiral, but maybe.

[Kevin Kuehn]

I think you're right about pin 4 being a tie point, because there's no pin 4 or 6 on a 1B3.