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-   -   Craigslist Zenith Score! (http://www.videokarma.org/showthread.php?t=251507)

fsjonsey 06-29-2011 11:54 PM

Craigslist Zenith Score!
 
http://i168.photobucket.com/albums/u...0_195982_o.jpg
I picked up my first all tube Color set today, from a seller in the Collinwood neighborhood of Cleveland. It's a 1966-67?? Zenith, still running on almost all of it's original tubes. On top of that, I found something interesting upon taking the back off the cabinet. There was what appears to be a space command tuner laying loose next to the chassis. It appears that the volume control also has a plastic gear drive attached to it, with happens to be cracked in two. The motor and space command receiver are missing, however. I'm guessing that the space command broke at some point in the past and was simply replaced by a manual tuner. Upon first power up, HV was very low and the picture bloomed and went out of focus as the brightness control was increased. A new 3DJ3 took care of that problem. The Electrolytic cans stay nice and cool, too! I'll post the model and Chassis numbers in a little bit.
Sorry about the poor quality iPhone pic. I'll post better photos soon.
Also, How hard would it be to find the missing Space Command components?

fsjonsey 06-30-2011 01:10 AM

This was the extra tuner I found laying in the cabinet.
http://i168.photobucket.com/albums/u...h_IMG_0362.jpg

DaveWM 06-30-2011 09:06 AM

sweet. cool cabinet. are the reds weak or is it just the programming (looks a bit weak to me)?

Sandy G 06-30-2011 11:03 AM

Kewl score !

fsjonsey 06-30-2011 12:05 PM

Quote:

Originally Posted by DaveWM (Post 3007773)
sweet. cool cabinet. are the reds weak or is it just the programming (looks a bit weak to me)?

It's the lighting and my iPhone camera. CRT tests strong on all three guns.

fsjonsey 06-30-2011 03:36 PM

Well, I have a problem. Went to turn on the set this morning, and a raster never appeared. I can hear some HV whine and audio, but nothing else. The set played fine all last night. Where would be an obvious place to look for a problem like this? I checked the HV rectifier, horizontal output tube, and damper, all tested fine.

Zenith26kc20 06-30-2011 04:32 PM

Can you hear the high voltage "crackle" when it comes up? If so, look for the video output tube and see if it is lit. I have a similar chassis, different model that gives a nice picture.
Also, check your focus rectifier. I am not sure but on some sets no focus voltage can cause no raster.

fsjonsey 06-30-2011 04:49 PM

Quote:

Originally Posted by Zenith26kc20 (Post 3007797)
Can you hear the high voltage "crackle" when it comes up? If so, look for the video output tube and see if it is lit. I have a similar chassis, different model that gives a nice picture.
Also, check your focus rectifier. I am not sure but on some sets no focus voltage can cause no raster.

Do you mean the crackle as the picture comes up and into focus, If so that's what I'm not getting. I'll check the focus rectifier, it's the green "stick" rectifier, correct? Just test it as a diode?

DaveWM 06-30-2011 04:59 PM

use a HV probe to monitor the CRT anode voltage

is the HOT red plating? wiggle the HOT and the horz osc tubes. hold a neon bulb near the plate cap of the HOT (I have one mounted to a small plastic stick).

I would pull the HOT plate cap off, check for B+, if that checks then I would put it back on and check the HOT grid for about -50v, screen voltage of around 150v. Also check the cathode current of the HOT.

This is where a tv analyst like a B&K 1076 comes in real handy.

DaveWM 06-30-2011 05:03 PM

you cant check the focus stick like a reg diode. You can just check the focus pin of the CRTwith either a meter like a simpson 260 on the 5kv setting or just a reg HV prob, the same as used in the CRT anode. Check to see around 5kv

fsjonsey 06-30-2011 05:09 PM

Quote:

Originally Posted by DaveWM (Post 3007799)
use a HV probe to monitor the CRT anode voltage

is the HOT red plating? wiggle the HOT and the horz osc tubes. hold a neon bulb near the plate cap of the HOT (I have one mounted to a small plastic stick).

I would pull the HOT plate cap off, check for B+, if that checks then I would put it back on and check the HOT grid for about -50v, screen voltage of around 150v. Also check the cathode current of the HOT.

This is where a tv analyst like a B&K 1076 comes in real handy.

The HOT is not red-plating, and has a mild blue glow. I don't have an HV probe right now, but will borrow one from a friend. Neon lamp lights near the plate cap of the HOT.

DaveWM 06-30-2011 05:13 PM

I would try a new HV rectiifier tube, assuming the HV is not present.

fsjonsey 06-30-2011 05:15 PM

Quote:

Originally Posted by DaveWM (Post 3007802)
I would try a new HV rectiifier tube, assuming the HV is not present.

I'll give that a shot, though I just replaced it with a NOS one last night.

3Guncolor 06-30-2011 08:14 PM

From looking at your pictures that set never had space command. Sorry.

fsjonsey 06-30-2011 11:11 PM

Quote:

Originally Posted by DaveWM (Post 3007802)
I would try a new HV rectiifier tube, assuming the HV is not present.

Bingo. The "new" one i installed yesterday must have been a dud.


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