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-   -   Motorola 12K2 restoration (http://www.videokarma.org/showthread.php?t=251132)

bandersen 05-17-2011 08:40 PM

Motorola 12K2 restoration
 
I'm finally getting around to the bug eaten set I picked up in Cincinnati over a year ago.

It's a Motorola 12K2 with a TS-53 chassis and 12LP4 CRT.

Some trim is missing and wood bores have been at it, but otherwise the cabinet and chassis are intact.

The CRT is a little weak, but I think it will produce a watchable image.

http://farm3.static.flickr.com/2587/...db5851dc62.jpg http://farm5.static.flickr.com/4062/...ab07867f8f.jpg
http://farm2.static.flickr.com/1297/...971c87ec68.jpg http://farm6.static.flickr.com/5304/...3f88f33ef7.jpg

I have some nice mahogany veneer I can use to reproduce some of that trim.
The veneer is a bit beat up, but I think I can salvage it.
http://farm2.static.flickr.com/1421/...d930061367.jpg http://farm6.static.flickr.com/5110/...772a9036ba.jpg http://farm3.static.flickr.com/2299/...f130091e4a.jpg

6GH8cowboy 05-17-2011 08:59 PM

We had that model at the TV shop where I worked until the early 80s. It worked. I would fire it up every now and then and it would get the looks by the passers by. I almost screamed like a little girl when I saw it missing when I stoped by in mid 80s. The owner sold it to the Burt Reynolds theater as a prop! I had an RCA 1948 in a metal cabinet but this was just an awesome looking piece in its wood cabinet.

TerrySmith 05-17-2011 11:36 PM

Something seems missing, like the HV section. And that power transformer looks awful small!

David Roper 05-17-2011 11:48 PM

Nothing missing. That's only a filament transformer; there are seleniums underneath in a voltage doubler arrangement. The Flyback and 1B3 are also mounted underneath. Motorola made many variations of this chassis.

bandersen 05-17-2011 11:52 PM

Quote:

Originally Posted by TerrySmith (Post 3003494)
Something seems missing, like the HV section. And that power transformer looks awful small!

That's what I thought before I saw the service info. The flyback and HV rectifier are hiding under the chassis.

The power transformer is just for some of the tube filaments. There's another transformer below for a few more tubes including the CRT.
The B+ comes from rectifying and doubling the AC line. So, it's a hybrid hot chassis, transformer set!

(Doh! David beat me to it :))

Grrr - broken capacitor wafer mount.
http://farm6.static.flickr.com/5103/...2e76670472.jpg http://farm4.static.flickr.com/3636/...be2facbaba.jpg

The yoke is a replacement. I tested it and the flyback using an Eico 944. Both passed although the flyback gave a high pitched squeal.
http://farm3.static.flickr.com/2098/...fac400c6_b.jpg

DO IT RIGHT! I've seen this on a couple other late 40s Motorola chassis, but not on earlier ones.
Maybe they were making too many mistakes on the line ?
http://farm6.static.flickr.com/5303/...d45c0308_b.jpg

bandersen 05-18-2011 12:06 AM

Here's the only odd thing I've found so far. It's three 1K resistors in series connected between the focus rheostat wiper and ground.

I don't see it on the schematic or other photos I've seen of this chassis :scratch2:

http://farm6.static.flickr.com/5201/...9a618afe_z.jpg

kvflyer 05-18-2011 08:26 AM

Well Bob, glad to see that you are off to another adventure! The progress should be fun to watch and I look forward to it.

wa2ise 05-18-2011 01:15 PM

Quote:

Originally Posted by bandersen (Post 3003501)

DO IT RIGHT! I've seen this a couple other late 40s Motorola chassis....
Maybe they were making too many mistakes on the line ?
http://farm6.static.flickr.com/5303/...d45c0308_b.jpg

:D Rather lame management if they thought that placing such stickers on the chassis would make the difference. :scratch2:

ChrisW6ATV 05-18-2011 09:23 PM

IBM had "Think" signs in their offices; a friend of mine has one from the 1930's that he used to keep in his office (at IBM). I wonder how well those worked?

mbates14 05-18-2011 10:28 PM

well enough that their laptop lines were "think"pads

init4fun 05-19-2011 08:11 AM

Hi Guys ,

Ill bet your absolutly right , , the "Do It Right" stickers were probablly the 1940s version of "The Team Concept" and other vapid management slogans that are supposed to get us worker bees in line . Didnt work then , dont work now , and a typical example of corporate waste . If these companies want good , happy workers who take pride in their work there is only one sure way to accheive that ...... Pay them a fair wage and make them feel like they ARE actually a valued asset to the organization . Everything else is just smoke .


Anyway , Im watching your Motorola restoration thread with intrest , , , , I may just have to go out and find some nice old TV to restore here myself ( Ive already done a 1950s Olympic , I just dont know how to post photos here yet) .

Oh yea , also , , , Ive reported "rootasoo" s post (the one that Is , or was , above mine) as spam :nono:

DaveWM 05-19-2011 08:23 AM

that looks a lot like the motorola I have, have fun with that cluster of caps at about 8:00 for do it right, must be 10 tied to one term strip lug.

kvflyer 05-19-2011 09:54 AM

Looks like it should be a nice "fix-up" and we will be watching.

O.T. We should be the brains behind these lame campaigns that they sell to corporations. The Bell System went through that stuff in the 80s and by 5 years later, all of the stuff that they crammed down our throats was out the door and laughed at (as we did behind their backs ;)). Large corporations seem to think that they can solve any problem with another pile of Bovine Scat slung at the workers. They always seem to think that they are superior and smarter than their worker bees. (rant off)

cwmoser 05-19-2011 10:34 AM

Quote:

Originally Posted by kvflyer (Post 3003653)
Looks like it should be a nice "fix-up" and we will be watching.

O.T. We should be the brains behind these lame campaigns that they sell to corporations. The Bell System went through that stuff in the 80s and by 5 years later, all of the stuff that they crammed down our throats was out the door and laughed at (as we did behind their backs ;)). Large corporations seem to think that they can solve any problem with another pile of Bovine Scat slung at the workers. They always seem to think that they are superior and smarter than their worker bees. (rant off)

Bell System huh? I worked for them too.
Remember the campaign PPP - Pride in Personal Performance?

We jokingly had other words for PPP :-)

Carl

bandersen 05-19-2011 11:51 AM

Quote:

Originally Posted by DaveWM (Post 3003649)
that looks a lot like the motorola I have, have fun with that cluster of caps at about 8:00 for do it right, must be 10 tied to one term strip lug.

I started on that cluster last night. Fun is right :drool: I've found evidence of a few crude repairs including some 6AG5s in 6AU6 sockets.


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