21" black and white of course , working but doesn't totally fill out the screen at the top and bottom and the contrast is a bit grey with not enough to add , schematic/sams shows black beauties in those circuits so if I replace them the set will show a vast improvement.

mike

Nice looking tv ! I would like to get one like those one day..... and a larger cleaner office to put it in...

21" black and white of course , working but doesn't totally fill out the screen at the top and bottom and the contrast is a bit grey with not enough to add , schematic/sams shows black beauties in those circuits so if I replace them the set will show a vast improvement.

mike

Sorry! That's a 1958 model.
I liked those a lot better, as they had a flat mounted chassis, instead of that hard to work on, upright chassis, where the entire unit pulled out of the front of the cabinet.
I think Zenith listened to the service techs and went back to the flat mounted chassis design.
I don't remember if they had the cover, the removed, to gain access to the under chassis, that early.
It still was a great improvement, over the 1956-57 models. :thmbsp:

I gotta remember that.......

That is identical to the 24" that I was trying to give away in to a good home in the classifieds. Never found one, so I parted it out. I still have the complete chassis including all the Space Command stuff if you need anything. I really hated to see that set go that way, but I had to have the space.

I meant to use it as a daily use set, but never got vertical sweep and there was some problem with the video detector diode and coil. It would have been great with that large 24" tube that was like new, not to mention the remote control. Can't win them all I suppose...

Ah ok thought it was 57 since the sams is dated early 58 , no you can't access the chassis from underneath or it would make things a little easier since all it needs is bumblebee cap replacements , will double check the electrolytics , yes the crt goes way up on the tester , its like the woman who had it only watched the news for an hour every night , its really strong , I don't think it was replaced, it was always kept in a good environment.
the 24 inch sounded cool , too bad you weren't closer , however as far as parts if you have them I may want some just for spares like the fly and other transformers if they are the same

mike

Ah ok thought it was 57 since the sams is dated early 58 , no you can't access the chassis from underneath or it would make things a little easier since all it needs is bumblebee cap replacements , will double check the electrolytics , yes the crt goes way up on the tester , its like the woman who had it only watched the news for an hour every night , its really strong , I don't think it was replaced, it was always kept in a good environment.
the 24 inch sounded cool , too bad you weren't closer , however as far as parts if you have them I may want some just for spares like the fly and other transformers if they are the same

mike
The CRT in the set is a low G-2 design. It depends what kind of a CRT tester was used. If it's an old B&K, it'll read way high. :scratch2:

the 24 inch sounded cool , too bad you weren't closer , however as far as parts if you have them I may want some just for spares like the fly and other transformers if they are the same

mike

The chassis from that point to several years ahead were nearly identical, with of course some component changes. I noticed when I had mine and compared it to others that they used different power supply rectifiers for some reason. Mine used (I think) a 5AU4, where most sets of that era used a 5U4. I assume that it was the extra loads involved with the Space Command goodies.

IF you need any parts, my chassis seemed almost unused. It came clean as a whistle with a full compliment of stock Zenith tubes. I never understood why a set of so little use and known for awesome performance was so hard to get working. A complete recap left the set exactly as it was when I brought it home. Usually you get to see noticeable improvement as you replace old capacitors & resistors. Not in my case, so I often thought that the set was flawed very early on, if not when new, and then got stored for many years.

So my transformers and such should be in super shape if or when you need one. I will probably take the new capacitors out and try to use them in other sets.

The crt on the tester requires certain settings to test it or else it will pin the needle , so it is good .
I guess I will send you a pm to check that the part numbers match , was thinking it would be nice to have a spare vert tranny and other stuff that's not easy to replace as a cap or resistor or tube.

mike

The crt on the tester requires certain settings to test it or else it will pin the needle , so it is good .
I guess I will send you a pm to check that the part numbers match , was thinking it would be nice to have a spare vert tranny and other stuff that's not easy to replace as a cap or resistor or tube.

mike
It's great that you have a newer tester, to properly check the newer CRT's.
I worked with older techs that only had the first B&K's, that wouldn't check the newer CRT's. :sigh:

It's great that you have a newer tester, to properly check the newer CRT's.
I worked with older techs that only had the first B&K's, that wouldn't check the newer CRT's. :sigh:

With these tubeless flat panel sets all the rage, I believe that the old B&K will end up being of more use than something for the later c.r.t. sets that people are giving away. The cool part about what is happening is that since everyone HAS to have the latest "technology", there are TONS of what only a few years ago were highly desirable sets. Now the best ones weigh more than a Dumont RA series set, but with the savings on a purchase you can pay some muscle to move it! :thmbsp:

Mine was the 18C24Q chassis. Yours is probably an 18C20. Your chassis will be identical, possibly with a 5U4 instead of a 5AU4 rectifier, and other small changes or actually lack of changes necessary for Space Command. With what I have yours could become a Space Command in a heart beat!!! I forget if the flip down control cover says just Zenith or Zenith Space Command.

Seems like there was a piece of raised plastic or metal script mounted on my C.R.T. surround bearing Space Command 500. Anyway, I found a Sam's .pdf that I can email you. This site does not allow space for the 4+Mb upload. I hope this is a help to you. And I am regretting the scrap job more and more now that there is a fellow enthusiast on board. I felt like I was the only owner in the world of one of these, but I will never get it because my set was not what you would call common. Not that many people had a remote set with a large 24" tube to stare at! At least not compared to those who had 21" ers, which was pretty standard.

I stick by a statement that I have made in the past. It doesn't have to be a "roundie" or a junk Predicta to be VERY cool and well worth purchase, use, and enjoyment.

If he is not interested in converting his set to space command then I might be depending on what it would cost to get the parts from you.

no I don't want to try to convert it to space command , nice idea but I don't want to do it partly because I would have to alter the exterior wouldn't I ?

my is chassis 17a20 sams dated 3-58 that's why I thought it was a late 1957 model because weren't the sams always out a couple months or so after the sets were out ?
so yours was a little later or earlier ?

I still have a pulling issue on the left side , tried resistors and it didn't change much , perhaps the new cap I put in that section isn't right ? if it had linearity that would cure it but all it has is width and that's a sleeve on the neck of the crt and it will squeeze the middle and barely effect the left

mike

Check for any adjustable coils past the oscilator. Zenith sometimes gave the lin adjustments different names later on like 'Efficiency'.

i will recheck the schematic but don't recall seeing any adjustables

Got centering rings ??

73 Zeno:smoke:

yes I tried the centering rings , they pull too , if adjusted so the right side is pulled the left is still pulling , perhaps changing the value of a replaced cap might alter this but I think I might have it to the point now where its not annoying and may just leave it , there is a possibility I didn't think of , there are a couple mica caps in that area I forgot to check , if one is leaky then it could be the fault , perhaps one day I will open it up again and look this over

If he is not interested in converting his set to space command then I might be depending on what it would cost to get the parts from you.

OK, I must not be reading these post closely enough. I just PMd Kramden66 about some other chassis parts and asked him about this. We have seen his answer already, so if you want the Space Command stuff get with me (PM) and we will work something out. The only thing I don't have is the remote its self.