Meck XB-702 restoration

[jr_tech]

C5 and C6 appear to be backwards

jr

[Kevin Kuehn]

Originally Posted by jr_tech

C5 and C6 appear to be backwards

jr

Ah. I was looking at Riders, which has those correct.

At any rate I think Bob found the smoking gun in an unsuspected area.

[Yamamaya42]

Originally Posted by Kevin Kuehn

Ah. I was looking at Riders, which has those correct.

At any rate I think Bob found the smoking gun in an unsuspected area.

always where you least suspect

[bandersen]

Originally Posted by Kevin Kuehn

Ah. I was looking at Riders, which has those correct.

At any rate I think Bob found the smoking gun in an unsuspected area.

Yeah, this felt like an HK short issue all along. The one tube I never thought to test was the CRT

[Yamamaya42]

Originally Posted by bandersen

Yeah, this felt like an HK short issue all along. The one tube I never thought to test was the CRT

[url=https://flic.kr/p/2n3GguK]

OUCH!

finding another 7JP4 will be impossible.

risk trying to burn it clean or, use a separate transformer for it?

[Electronic M]

Originally Posted by Yamamaya42

OUCH!

finding another 7JP4 will be impossible.

risk trying to burn it clean or, use a separate transformer for it?

Bob's in Chicago within driving distance of me in Milwaukee...And I do have a spare good 7JP4...(heck I have the three amigos of 40s CRTs 7JP4, 10BP4, and 12LP4 sitting in my spare pile.)

[old_coot88]

That tube tester's veracity is questionable regarding an HK short in the CRT. If there were a heater-to-cathode short, it would kill the video signal going into the CRT as well as show a heavy hum bar (since the heater is 6 VAC away from ground, thru the 6X5's heater). In a case like this, the TV itself should be the best "tester" of the CRT.

[bandersen]

Originally Posted by old_coot88

That tube tester's veracity is questionable regarding an HK short in the CRT. If there were a heater-to-cathode short, it would kill the video signal going into the CRT as well as show a heavy hum bar (since the heater is 6 VAC away from ground, thru the 6X5's heater). In a case like this, the TV itself should be the best "tester" of the CRT.

You are correct. I had both F2 and K set to pin 2

So back to the drawing board. The tuner filament transformer and filter choke seem likely candidates. I could power the tuner with a separate 6 volt source.