Quote:
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?