Late 1940s Air King Project

[tvcollector]

Same set that's listed in this auction:

http://www.ebay.com/itm/201413617088...%3AMEBIDX%3AIT

As some may know I received this in the mail and has got some Horizontal issues.. So far I'm testing the tubes in the HV cage and the 12BH7 is testing very weak, in the lower bad range.. Not sure if that would cause the Horizontal hold to be slightly off..

I'm still trying to the find the right Sams Photofact for this, which I posted before: Does anyone know the Sams photofact series and folder number to this chassis? I went ahead and ordered this one, http://www.ebay.com/itm/361198838937 then I realized the Chassis number is the same number but for a Majestic brand.. Perhaps I may have ordered the right sams, if not, will have to cancel the order.. I also found that it could be Set No. 121.. But not sure, and if anyone has the right set, I would be interested in it... Let me know.. Thanks...

[SwizzyMan]

Getting an error when I click the link.

[Eric H]

Moved this to the B&W Forum.

[Eric H]

My Sams index has an Air King 12C1, 12T2 and a 12T01 and they all use the Sams 121-3, I don't see a 12T1 listed under Air King at all.

The auction just lists it as a 12T, does the chassis or label have an actual model number on it?

I don't see any Majestic sets using the 121-3 Sams number.

It's not uncommon for sets to have similar chassis numbers, the 12 is just the screen size, the T probably means Television and the 1 might indicate their first model.

I see Andrea, GE and Motorola also have 12T1 model numbers.

[tvcollector]

Oops.. I meant to put it here.. Don't know how I managed to post in the early color section.. Between my A.D.D. and using that forum section more I guess.. Links should work now too..

The set contains three 12BH7 tubes, and all test weak, some more weaker than others, and the 5U4 located on the transformer is also weak...

[Eric H]

Is one of the 12BH7's the horizontal oscillator? A new one might help but you might also be able to tweak the horizontal frequency coil to bring it into range, it's also possible a resistor in the oscillator circuit has drifted.

Has the set been recapped completely?

[tvcollector]

One of the 12BH7 tubes is Horiz Mult... I did exchange a slightly stronger one and switched them around and the screen would not fill in on one side.. all the caps look to be replaced and alot of the resistors..

Here's some pics:




Not sure where the Horz osc adjustment is, but I assume it's one of these little flat head screw driver adjustments seen in these pics.. I don't have the full correct sams photofact:




Bottom of chassis:

[tvcollector]

I have that photofact folder but it shows models 16" and up.. Doesn't say anything about the 12T2 model.. Looking at the parts list, L23 is the Horiz Freq coil which points to a coil that should be next to the Horiz Drive control on the underside and the coil next to it is an A.F.C. coil, but obviously it's showing a different chassis.. Or unless the Horiz drive control is the Horiz Freq control, and that's all the way up, nor does it change the pattern of the screen when adjusting or make the ringing noise of the HV... Also on the top of the chassis next to the HV cage are the two flathead adjustments and the square can which is sound, one according to the sams one is Horiz Lin and other is Sound IF...

[jr_tech]

The horizontal frequency is controlled by the slug on the back of the chassis between the Focus and Horiz drive adjustments. "AFC" is the Horizontal auto frequency control.

jr

[tvcollector]

Ok, I assume I adjust the AFC control.. Never would think AFC coil would have anything to do with locking the Horizontal...

[dieseljeep]

The horizontal frequency coil is the only one you should try to adjust.
The model number 12T1, designates, that it's a 12" table model set. It doesn't appear to be that far out of frequency.
Once the horizontal is synced in, if the picture is shifted, try adjusting the horiz centering control.
As I mentioned in a previous entry, the Air King, CBS Columbia chassis were rather similar for a few years, for all screen sizes.

[tvcollector]

I adjusted the AFC, and have to turn the set off and back on to see results.. Got it to lock... But as soon as you fine tune, it will go out of wack again.. Change the channel and back again it will lock again.. Lots of buzz coming from the speaker, and when there is a bright picture it gets worse, when I fine tune to where there the picture doesn't come it, the buzzing goes away and the sound is much better... One of the 6AU6 tubes that's in the sound circuit is weak too...

[AUdubon5425]

Air King was purchased by CBS at some point, probably explains the similar chassis

[Eric H]

I'm going to take a guess that this coil I have circled is the actual Horizontal Oscillator frequency adjustment, if that tube next to it is the Oscillator I'd be fairly sure of it. It could also be the width or drive coil possibly.

It wouldn't hurt to give it a turn one way or the other and see if the picture falls into place.

The AFC will also affect the frequency but I believe the other one is the one to be concerned with for now.

[Eric H]

I just noticed another adjuster near the one I circled, it could also be one of the above mentioned (drive, freq, width) adjustments.