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Old 10-15-2017, 07:46 PM
init4fun's Avatar
init4fun init4fun is offline
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Join Date: Mar 2011
Location: Eastern Massachusetts
Posts: 627
So of course I just COULDN'T scrap it .....

At least not without a fighting chance !

The backstory ; I have here a Zenith TV that I really want to restore but when I got it (with all the other contents of a radio/tv repair shop) it had "picture tube dead" scrawled across the screen with the kind of "grease pencil" used car dealers write the prices on the car's windshields with . Now I really do want to restore this set because it's identical to my daily watcher I had back when these were new , but there is that dead tube to deal with . Just for grins I recapped the sencore CRT tester that came with the haul and while it showed a couple of my other CRTs in other old B&W tvs as being good this set's CRT barely moved the needle and didn't get much better with an increase in heater voltage . Ok , so the tube is bad or so it seems , and I put a wanted ad here to which I had no success . Darn , not really having the space to store unrestorable sets due to an upcoming move I was really dreading the prospect of having to either give it away* or junk it . Now I really really REALLY didn't want to junk it but that seemingly unobtainum picture tube was the "death knell" and I figured I'd at least keep the working space command chassis in the slim to none chance I ever ran into another set with a good tube in the future .

But then , I read in Ben Moyer's thread where he mentioned sometimes crts that read badly on crt testers can still give an acceptable picture and so just for grins I figured I'd recap the power supply and see just how "dead" the picture tube actually is . I didn't take a picture of power up #1 but a small amount of light appeared on the screen , not enough for a watchable picture but enough to encourage me to plug one of the 25 or so brand new CRT brighteners onto it I've got and power up attempt #2 yielded this nice bright screen . It's hard to see in my picture but by adjusting contrast & brightness and rotating the fine tuning knob I got nice well defined snow (nothing handy to put a signal to it , recapping the B&K 1077 is next up on the to do list) that changed with the movement of the fine tuning control .

The data tag on the back said 290 watts , which it hit exactly when the power tuner was operating , and it ran at 240 watts with no tuner action , with the space command chassis alone accounting for 30 of those 240 watts . So 210 running watts for the TV chassis itself (the watt meter was on the high range) seems normal and after 15 or 20 minutes of running the flyback was room temperature with no signs of anything else overheating .

So there ya have it , it now will get restored when I get my stuff set up in a new place and I may well then have a few questions as I recap the rest of the set , so far only the power supply's electrolytics have been changed and I know at least the vertical needs some attention as the raster you see is all that the height control could muster .

* You'd be surprised how hard it can be to give old electronics away in my area . It seems there is so much really good condition vacuum tube equipment still available here that no one wants the "basket cases" . I see some folks in other parts of the country bemoan the dearth of nice old TVs in their area and think "what a shame , when here you literally can't give most stuff away" unless it's just about picture perfect .
Attached Images
File Type: jpg zenith tv alive 1.jpg (43.4 KB, 218 views)
File Type: jpg zenith tv alive 2.jpg (46.4 KB, 80 views)
File Type: jpg zenith tv alive 3.jpg (46.1 KB, 69 views)

Last edited by init4fun; 10-15-2017 at 08:07 PM.
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