View Full Version : So of course I just COULDN'T scrap it .....


init4fun
10-15-2017, 08:46 PM
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 .

Jon A.
10-16-2017, 12:24 AM
I don't think CRTs for those are unobtanium, perhaps you could just liberate one from a lower-end set. I've seen sets like that mentioned here before.

madlabs
10-16-2017, 10:45 AM
Yep, never say die! Always worth a shot. Congrats!

init4fun
10-16-2017, 06:57 PM
I don't think CRTs for those are unobtanium, perhaps you could just liberate one from a lower-end set. I've seen sets like that mentioned here before.

Yep, never say die! Always worth a shot. Congrats!

:) Thank You for the responses guys .

And Jon , I wish it were true that the CRT was easily obtained but a wanted ad here turned up nothing , and come to find out it's a "low voltage focus" tube that not a lot of sets appear to have used . I do now believe this one will produce a good picture and it's not like I have any "Daily Watcher" plans for it anyway , just to be able to run it a couple or few times a year will be fine with me .

DavGoodlin
10-17-2017, 09:42 PM
We have similar trouble here, I'm loaded with sets and nobody nearby to trade with. All my TV-collector friends are at least 100 miles away.

Is that one a 1964? I have a similar non-remote 15L37 and thought that was a pretty common CRT.

Jon A.
10-18-2017, 06:25 AM
:) Thank You for the responses guys .

And Jon , I wish it were true that the CRT was easily obtained but a wanted ad here turned up nothing , and come to find out it's a "low voltage focus" tube that not a lot of sets appear to have used . I do now believe this one will produce a good picture and it's not like I have any "Daily Watcher" plans for it anyway , just to be able to run it a couple or few times a year will be fine with me .
I wouldn't form any conclusions based on your wanted ad, that set is too recent to fetch big bucks so only the most dedicated enthusiasts would be after them.

I'm pretty sure the Bradys had one like it early in the series; two of them were fighting over a Space Command 300 remote.

Strange, I hadn't heard of a low focus voltage CRT in a B&W set.

Electronic M
10-18-2017, 01:23 PM
If you define a CRT's rarity by the ability to get one in under 6 months, then most CRTs made are very rare. Unless you need one that a resource happens to have sitting listed for sale odds are it will take plenty of patience.