Westinghouse K840CK15 Restoration

[benman94]

The flybacks on the 15 inchers don't seem to be terribly failure prone. I would reinstall the jug at this point and try to get HV, horizontal deflection, vertical deflection, even in a brief test, and a quick check of the convergence circuitry and CRT itself before going any further. My 2 cents...

There's little sense in continued restoration efforts if critical parts are dead. I don't like the test results of the 15GP22 at all...

[etype2]

Originally Posted by benman94

I don't like the test results of the 15GP22 at all...

The 21AXP22 in our 21CT55 tested like this.



These figures are about the same as the test on 15GP22.

As we have posted on another thread, the 21AXP22 puts out a decent image despite the tired CRT. I wonder what criteria was used by the ETF. The CRT was described “good” and “excellent” prior to the auction. Fingers crossed.

[benman94]

Originally Posted by etype2

The 21AXP22 in our 21CT55 tested like this.



These figures are about the same as the test on 15GP22.

As we have posted on another thread, the 21AXP22 puts out a decent image despite the tired CRT. I wonder what criteria was used by the ETF. The CRT was described “good” and “excellent” prior to the auction. Fingers crossed.

That 21AXP22 is definitely tired, and according to your own post, the green gun on the 15GP22 is even lower than the 0.8 reading you're getting on all the 21AXP22 guns.

Also keep in mind that for sufficient brightness, you'll have to draw more cathode current from the 15GP22 cathode as it runs a lower ultor voltage than the 21AXP22 does (or should) in the 21-CT-55. 19.5 kV for the CT-100 versus 25 kV for the 21-CT-55. The difference in apparent brightness with the two different ultor voltages will be not be negligible.

At the very least I would expect poor tracking, and quite possibly insufficient green. I suppose your saving grace here is that the weakest gun is the green gun. If it were red, you'd be in worse shape...

I too am curious as to what happened here as far as testing goes. Your results certainly don't look "excellent". I don't doubt Steve's integrity. Perhaps your tester needs looking at? Do you have an extremely strong like new tube to compare with?

[Electronic M]

Originally Posted by benman94

I too am curious as to what happened here as far as testing goes. Your results certainly don't look "excellent". I don't doubt Steve's integrity. Perhaps your tester needs looking at? Do you have an extremely strong like new tube to compare with?

Personally, I have limited faith in the ETFs CRT tests. I've had "excellent" tubes test significantly lower than advertised at home, and 'bad' tubes that were good but lightly asleep and could have been confirmed good with a bit of patience...

I'm at the point where I rather test it myself before bidding my top dollar than trust the accuracy of the posted info.

My guess they either have an iffy tester, an iffy operator, are taking consigner's word for CRT health or some combination thereof.