Motorola 12T2 Restoration Restart
 

This Motorola 12T2 is my family's first television set. I spent many hours sitting in front of this set, learning about life from Howdy Doody and Captain Video.

https://lh6.googleusercontent.com/-i...scued%2521.jpg

A few years ago, starting at electronic ground zero, this was my first project. I had a pair of dull wire cutters that could only crush wire; an analog volt-ohm meter that didn't quite work; a soldering iron that couldn't melt butter; and a lot of guidance from Phil Nelson. After several months of work, I was stopped by a bad deflection yoke.

Now, with a little more experience and a great deal more equipment, I've finally picked up a replacement yoke and I want to restart the project. The first issue is, "Do I have the right yoke?" The only difference I can see is the resistance across the coils.

https://lh5.googleusercontent.com/-w...%2520Yokes.jpg

Can I go ahead with this yoke?

According to my Thordarson replacement guide Y18 does appear to be the correct sub. And I don't see a problem with the DC resistance being off a bit. I think impedance is the more critical value, and I'm sure Thordarson took that into consideration. Looks like your TV was taken very good care of over the years.

Thanks, Kevin. Electromagnetic fields are still a mystery to me. I've done a bit of studying, but I just can't buy this "electron theory."

I've subbed yokes of different makes on similar tubes blindly, and had it work.
If more than one cross reference says it's good, then as long as the replacement is not a dud you have nothing to worry about.

TRUST me you do not want to learn Maxwell's equations (which completely describe/explain electromagnetic and electrostatic fields). The calculus involved in properly understanding/applying them will fry your brain!

As long as your new yoke is a 52 degree deflection, it should be fine. Thordarson always made the best replacement parts. :thmbsp:

I always though calculus was a fancy name for an educated guess. ;)

Yeah, that pretty much sums up how I do calculus...

Cross Reference for Yet Another Part?
 

Focus coil for this Motorola 12T2, chassis T-53
The coil was open. I cut open the case and repaired 3 breaks, got 700 ohms through the coil, and rewound it. I’d like to find a good NOS or used part in case this one doesn‘t work.

https://lh5.googleusercontent.com/--...%2520break.jpg

I only have Motorola part numbers:
Original part is 24B792581 I.T.E
Sams (part T6), same number 24B792581 (650 ohms)
Rider (part L24) number is 24K700655 (670 ohms)

Can someone help me with a cross reference for this item?

Still hoping someone has the time to look up other part numbers for this focus coil:
original part 24B792581 I.T.E
or 24K700655 (from Riders)
Thanks

Unfortunately my Thordarson reference doesn't cross focus coils. And I think Thordarson only ever made 4 types. Probably because manufactures quickly transitioned to permanent magnet focus.

Thanks for trying.

Have you tried contacting Moyer's with the part numbers you have and see if they can provide cross references

http://www.moyerelectronics.com/Depa...-TV-Parts.aspx

Meanwhile, if you rewound the coil with the same gauge of wire and same number of turns, is there a downside to trying this one out?

Phil "ever the optimist" Nelson

I did contact Moyer. They said that none of the replacement companies list it and they never had original Motorola parts.

Phil, I repaired several breaks, then rewound the original wire. The resistance of the repaired coil (700 ohms) is close enough to the original spec (670 ohms), so I will try it. But if I had a known-good coil, then I'd use that instead.

Thanks.

I'd guess that unless you reused the old wire, and scraped enough of the insulation off to cause shorts that it will work fine. Rewinding simple reasonably thick wire coils like that is usually a successful process.

BTW, is it just me or does your avatar look sadder recently?