Bought a '65 Magnavox console
 

Hi everyone,

I bought my first project TV, a Magnavox 10T338N from 1965 I believe. The picture tube it marked 75E, 23MP4, 836, date code 520. At the seller's house, the set had audio but no video. After the ride home, the audio disappeared too.

Where can I obtain a schematic for this set? I couldn't find anything through google. Any advice is appreciated!

Thanks,

Ryan M. Landry

Neat set !

I did try to look up that number, no luck...
You should be able to get a Howard Sams Photofact/schematic for this set. What is your model number and chassis number? Anyone with an index book or visiting the Howard Sams website can provide you with the Photofact number. Once you know that, many folks (and AK'ers) may help you to obtain one. Also, if you have a county library they should have a technical section loaded with photofacts too that you can copy from.
A thing to remember about Magnavoxes and numbers....The cabinet itself may have it's own number but it is just about useless to obtaining schematic info. And that number may or may not necessarly be the "model" number! If indeed it is used as a model number, all the better. Plus, that chassis was used in many models/cabinets so a chassis number should always be valid.
So, all that being said, you may be looking at two, or three numbers to dissect from and go from there. Keep us posted!

Great lookin set. Don't fire it up until you replace the power supply capacitors at the very least. 40+ year old parts do not belong in there. :no:

Hey Ryan,

Cool set, I wouldn't mind having one of those myself.

Search for this thread "Beginners guide to Vintage TV Restoration?" on AK it has alot of good info to get you started, that is if your a novice like myself. I've got two under my belt and a third one started. I could have never pulled it off without these guys.

Good Luck and have fun.

Chris

Thanks y'all. I'll look for that beginners' guide. I'm going to dig into the set this weekend or next week and try to find a chassis number.

I never seem to have very good luck on using the search engine on AK. What is the secret for using more than one word? I can narrow things down by searching in just the tv sections. But I still get tons of post that are non relevant.

Here's the link to the beginners guide.



http://www.audiokarma.org/forums/sho...d.php?t=145086

Hi again,

I unbolted the chassis this evening and looked everywhere, but could not find anything that was obviously a chassis number. This is what I did find:

stamped in metal chassis: 730450-2
written on HV cage: 14/14/14/93
on tube layout sticker: EL 2072-1
on circuit boards: 210169-6, 210165-8
model no. on cabinet: 10T338N

I'm at a loss - I would really like to have a schematic but none of the numbers I found cross to a chassis number in the SAMS index. The only thing I found close was a listing for a chassis CT338 (series 105), but I'm not sure that's even a TV. If anybody has any suggestions, I could sure use them.

Thanks,

Ryan

Usually there is a sticker or marking on those magnavoxs that you wouldnt think is the chassis number . I had the same problem with mine before i finally found the chassis number and was able to obtain a sams . You should go ahead and replace those electrolytics and check all tubes , then that set just might fire up. Those orange drop caps and red mallorys were pretty reliable . Thats just my opinion becuase i did a few of these magnavoxs . THEY are one of my favorites .

Check SAMS 736, folder 3 - same boards and tube complement as your set, albeit in a portable. The RCA CTC-16 roundie is in the same SAMS, so it's a popular SAMS...

Cheers,

Found it! The actual SAMS is 779, folder 2 - matches your chassis exatly. You have a U44 chassis - yours may be late production, as the flyback part number in SAMS shows a -1, and yours is clearly marked -2.

Magnavox used some crappy tube sockets, so watch out for them.

Hope this helps -

Cheers,

Thanks so much Brian! I am extremely grateful to you!

Hello everyone,

I obtained a Sams for the set and dropped the chassis last night. Everything looked pretty clean except for two areas:

Someone did work to the horizontal AFC network, which is one of those all-in-one pc chips that look like a wide orange-drop cap with 5 leads (forgive me - I don't know the proper name for these.) They must have used a pretty hot iron, as heat blackened the board and cooked the insulation on a couple of wires. My question is: is there a good source for these chips, or are they made of unobtanium? Also, was there a reason other than convenience that the resistors and caps were integrated into the single chip?

Ryan

Hi everyone,

I'm about to finish re-capping this set (Magnavox U44) but have a question:

I was able to get a picture on the set, but it is very dim - only viewable in a dark room with the brightness almost fully up. When I pot the brightness all the way, the picture goes "negative" - like looking at a photo negative.

Any advice for me? Maybe some circuit in particular to double-check? Unfortunately, I don't have a CRT tester, I have a gut feeling the crt is bad, but am trying to eliminate any other possibilities for this condition.

Also, where could I find information on which tubes are compatible with a 23MP4, in case I have to start searching for one?

Thanks,

Ryan