Zenith 19L25 Chassis ( Service Info )

[newhallone]

odd. It looks like another number off to the left? I wonder if it's just set for 25 on 13 or if it is the whole uhf band that displays thru the center. If so there must be some way of rotating the uhf display.

[Phil Nelson]

What does the rest of the tuner look like?

Phil

[RitchieMars]

After looking through the service info that leadlike kindly put together for me, I'm pretty sure there's no UHF on my Zenith. It looks like there's supposed to be a separate tuner assembly mounted in front of the regular one which I obviously don't have in my tv. The knob itself should have UHF channel numbers listed around the outer circumference of the knob, which I don't have either.

Here's what the whole thing looked like the first time I removed it from it's cabinet.



Oh, and that other number was bleeding over in the picture because I was holding an LED to light it just for that photo. Properly mounted in the tv, it shouldn't show but one channel number at a time. 13 is the only instance where it projects a number other than what is shown on the gold bezel, in this case 25.

[rojoknox]

Greetings from FixitLand!

Originally Posted by RitchieMars

After looking through the service info that leadlike kindly put together for me, I'm pretty sure there's no UHF on my Zenith. It looks like there's supposed to be a separate tuner assembly mounted in front of the regular one which I obviously don't have in my tv. The knob itself should have UHF channel numbers listed around the outer circumference of the knob, which I don't have either. ...<snip>...Properly mounted in the tv, it shouldn't show but one channel number at a time. 13 is the only instance where it projects a number other than what is shown on the gold bezel, in this case 25.

Boy, that sure makes me believe you've got a Channel 25 UHF strip in the VHF tuner's Channel 13 slot. My set's channel knob shows only the VHF channels as well (but doesn't have that "projection" feature). Since you've got the chassis out, it should be quite easy to pop the tuner's cover off and check the turret. There would be two strips, one slightly longer than the other. All the strips are marked with their channel number.

Take care,
--
J. E. Knox 'The Victor Freak'

[RitchieMars]

My tuner seems to lift straight out the top as a whole unit, but sure enough, I did find this:



So what's the functionality of having the one UHF channel?

[Phil Nelson]

Probably the town where it was originally sold only had channel 25. UHF channels were scarce in the early days, and it's possible to construct a tuner that receives both VHF and UHF if the right strips are inserted. This article has a description of a 1953 VHF-UHF tuner. It also includes a journal article that describes the tuner in more detail.

http://antiqueradio.org/RCACT-100TelevisionDesign.htm

Phil Nelson

[RitchieMars]

I know how you guys like pictures as much as I do, so I thought I'd give this old thread a bump and put up a few of what this '53 Zenith L1846R actually looks like:



This is one of the first pictures I actually took of it, the day I brought it home. Cosmetically, it's in great condition and the only thing I'd really like to improve upon is the simulated "gold-plating" that's worn off on the control panel, particularly on the pencil box door.



Here's a good view of everything that's going on underneath the chassis. From what I've seen, everything there is probably original which calls for a complete recap. If you spot anything here that I should pay special attention to, do let me know! I hope to get to recapping this in the near future. It's a real pain to take this chassis out, mainly due to it's weight. Removing the CRT helps, but not as much as I'd like.



This picture came out rather blurry, but I recall thinking it was one of the weirdest looking things I've ever seen inside of an electronic device. Based on what I know now, I believe this is the flyback transformer. I suppose if it were bad, I wouldn't have gotten a horizontal raster... and if it goes bad in the way that most transformers seem to do, I take it that it would get very hot, the wax would melt, and bad things would happen!

When did they invent gray, glittery wax?