Quote:
Originally Posted by E_the_F
Hi guys! New guy to this site BUT does anybody know where I can find a replacement CRT for my Zenith porthole TV set (Model / Chassis H2437R)
The picture tube in mine is dead �� would LOVE to find a replacement! Thanks!
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If you're ever near Milwaukee I have a spare 16GP4 that opperated well enough to make a picture in my Zenith Porthole...I don't ship though so don't ask.
How did you test yours? Have you tested a known good CRT to test your tester? My 16GP4 was stone dead when I first hooked it up to the tester, but came back to life after a couple hours with the heater voltage on the tester set to 8.4V
Many CRTs that have been dormant for years to decades develop cathode poisoning (or sleeping sickness as other collectors call it) the cathode that skirts electrons is a highly reactive metallic compound similar to a getter (element placed in a tube to collect the gas particles that are contaminating the vacuum). The cathode behaves as a getter whenever it is not running and when that happens the gas it's surface collects forms a coating that blocks emission. If you heat the cathode above it's normal opperating temperature and draw a current (as an emissions test or normal opperation will do, either way still assuming you increase heater voltage) and let the CRT sit in that state for 15min-6hours often the CRT will wake up and produce usable emission. After 6 hours if still stone dead you have nothing to loose performing a rejuvenation on it.
Color CRTs waste ~%80 of their emission on the shadow mask (the rest hitting the phosphor and making light), monochrome CRTs waste almost no emission with virtually all emission striking the phosphor....The good-bad emission scale of basically all testers designed to test color CRTs is calibrated for color CRTs....So on a tester that can test color CRTs if a monochrome tests midway up the bad scale it should produce a watchable picture in a working set.