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I need a CRT tube tester
I am in San Diego California and I have several tvs that I need to test the CRT and I am not sure what to buy without spending a fortune. B&K and some others I see on Ebay look pretty beat up. Missing booklets and have not been tested, Can someone please make a suggestion and point me in the right direction?? Thnaks Guys, Scott
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#2
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BAMA (boat anchor manual archive) has a lot of test equipment manuals if you find something decent that's missing a manual.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#3
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Also check ham flea markets & ask around. I bet in the 70's
there were at least 30 shops in your city & lots of Eq to find. Recommend either a B&K or Sencore from the 70's on. Be sure it has a lot of sockets, set up book & owners manual. With a universal adapter you can test damn near any CRT. BTW if the sets run you can tell if a CRT is good by the symptoms & voltage measurements. 73 Zeno LFOD ! |
#4
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You can find good ones still. I bought a NOS Sencore CR161 for $100 a couple of years ago, still in the unopened box. There is a clean used one about to finish on eBay for $20 with all the manuals and sockets https://www.ebay.com/itm/25547383087...=&toolid=10050
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#5
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The best one I have ever used was the Heathkit IT5230. Lots of documentation still out there for these also.
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Audiokarma |
#6
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I have had one since 1978 and fried only one CRT, a Sony! Heathkit circuit was a similar to a Beltron.
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"When resistors increase in value, they're worthless" -Dave G |
#7
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CRT testers tested
I wanted to bump this thread after watching several of our brothers-in-cutoff use testers on youtube videos, once I actually have this equipment on hand to compare what a good tube looks like on their varied meters and lights. I figure this thread is useless without a Beltron, Heathkit, and traditional B&K tester comparison
This does not include some CRT testers that others have had success using to wake up and occasionally "belt, zap or hit" it , but ever so carefully. I have a BK 466 and a 467 which need some work, so they are out of my experiment. Never saw a Sencore CR31 or 70, either are a great choice. The control is a 23" Admiral 25AP22, that to my knowledge was never "cleaned" or "rejuvenated" but a chain of custody via other VK'ers. Best of all, it did not turn up with a cathode-frying brightener that increases filament voltage.
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"When resistors increase in value, they're worthless" -Dave G |
#8
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Here are all 3 testers, Heathkit IT5320 is set to compare cutoff of blue/red lower, with green highest at 10. Some allowance is made for this when the screen and drive controls are set-up.
HK cutoff - all3.jpg Two B&K model 467, each needs some work but there are many adapters also. Too bad those ABS plastic cases dont hold up. BK 467s.jpg Heathkit IT5320 cutoff control is set to peg meters on good emission, the "cleaning" function is similar to the Beltron and is usually sufficient to wake up a tired CRT HK full on.jpg B&K 445 has a switch for RGB, here its showing red's emission. The "dyn" lo-med-hi is discharge type rejuvenation, as risky as the Beltron's (socket 3) according to several accounts. BK445 full on.jpg The Beltron 2972D is a great tester. The cleaning (socket 2) effective, but don't use as much filament voltage (10) as the directions read, plus you know its complete when the lights all come on. Beltron 2972D.jpg
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"When resistors increase in value, they're worthless" -Dave G Last edited by DavGoodlin; 09-02-2022 at 11:49 AM. |
#9
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Conclusions
All testers can become tools of destruction for tubes with any life left by stripping emissive material from cathodes. Several times I have found a "lazarus" CRT that was literally raised from the dead, but not before I got rough with the HK's more controlled rejuvenation function. The BK 445 shorted a 21ALP4 K-G1 that refused to budge the needle on the HK.
The key is to get a look at the CRT in operation, confirm voltages to it including HV and at the video output tube. And, if it checks out yet looks sick then start slow and follow directions. If there was a brightener attached or you suspect some one has belted the CRT before, stop after doing the cleaning operations or you will strip whatever is left on the cathodes. I had a 21FKP22 (syl) that was fried beyond help. I have not had success cleaning a Sony trinitron, or most one-gun tubes from the 80s and later. Supposedly the cathode material was not just a coating but the entire element. The best overall tester is the Beltron due to it's not pegging meters like the Heathkit. But like the HK, cannot adjust G2 voltage, needed for certain tubes. Beltron close up.jpg The most versatile tester is the B&K with adjustable G2, though its filament voltage should be monitored. The Color 1 and Color 2 were specified for 21FJP22 and 23EGP22 respectively but both will run the heater in this 25XP22 at over 7.6 volts . 25XP22.jpg
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"When resistors increase in value, they're worthless" -Dave G Last edited by DavGoodlin; 09-02-2022 at 12:07 PM. |
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