Zenith A1512J restoration

[bandersen]

I finally got my hands on the rest of the set. The CRT turned out to be a headscratcher.

It's been rebuilt and the label indicated 14R/XP4. The 14RP4 is 600mA while the XP4 is 450mA so how could this CRT sub for both ?


I hooked it up to a CRT tester and it does draw 600mA which made me wonder how well it would work in this 450mA series set. Only one way to find out.

So it does work, but I have the brightness control nearly maxed out.


Now for a bigger issue. Serious lack of width. It's only about 50%. The schematic showing something called a "width sleeve" but gives no indication how to adjust it.


This is the first time I've encountered one of these. I assume it's this grounded ring around the neck Moving it around has little if any effect.

Any ideas ?

[Kevin Kuehn]

I've seen some sets that have what looks like one layer of brass shim stock wrapped around the neck. Sliding that in or out of the yoke changes the width. I wonder if that ring originally kept such a sleeve from shifting location?

[IsthmusTV]

My Zenith T1816 bug eye also has a width adjustment sleeve. I was able to vary the width by a combination of rotation and sliding it in and out. But the range of adjustment was relatively small. I don't think that it would be enough to fill out the width in your case.

I just saw Kevin's post. And yes, mine has the wire ring (with a ground wire) over the brass sleeve to hold it in place.

-Clark

[Kevin Kuehn]

Originally Posted by IsthmusTV

But the range of adjustment was relatively small. I don't think that it would be enough to fill out the width in your case.

I agree about the adjustment being minimal. I think I'd first take a look at the horizontal drive signal or horizontal output.

[Phil Nelson]

I experimented with a width sleeve when restoring my Capehart-Farnsworth 661-P. This article includes some explanatory paragraphs from an old TV service book:

http://www.antiqueradio.org/Capehart...Television.htm

The book says the ground connection is to prevent arcing from the sleeve to yoke windings.

In my casual experiments, pushing the sleeve in and out had quite an effect (granted, this was on a TV designed to use a width control, not a sleeve).

I don't see a sleeve in Bob's photo, only a ring. Is the sleeve pushed all the way into the yoke so that it's not visible?

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[bandersen]

Originally Posted by Phil Nelson

... I don't see a sleeve in Bob's photo, only a ring. Is the sleeve pushed all the way into the yoke so that it's not visible? ...

Bingo I need to take the set apart again and dig it out