Same set that's listed in this auction:

http://www.ebay.com/itm/201413617088?_trksid=p2060353.m2749.l2649&ssPageName=STRK%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...

Getting an error when I click the link.

Moved this to the B&W Forum.

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.

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...

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?

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:

http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0394.jpg


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:

http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0386.jpg
http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0388.jpg

Bottom of chassis:

http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0400.jpg
http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0403.jpg
http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0405.jpg

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...

http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0413.jpg
http://i1220.photobucket.com/albums/dd458/vintageceilingfans/Air%20King%20TV%2012T2%20Chassis%201949/DSCF0416.jpg

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

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

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. :scratch2:

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...

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

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.

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

The Sams (121-3) shows the adjuster slug on the back by the focus control as "b-1, horizontal afc"... The schematic shows b-1 as being the horizontal frequency coil L-23 which is in the plate circuit of the horizontal osc (v-14). The coil Eric circled is shown as "b-4 horizontal lin". The other adjustment above b-4 appears to be in the sound circuit (L-22).

jr

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

The one you circled in the picture is one of the adjusters next to the flyback cage that adjusts from the top of chassis.. It's most likely L24.. It shows up as being the Horiz Lin control according to the sams.. The other smaller coil next to the HV cage, closer the the back side of chassis is Sound IF...

JR Tech that's what has been throwing me off, is L-23 because that coil is not in the same place, or not even sure it exists in this chassis... For some reason it comes in on channel 9 better as my modulators are set to 10... There's also a wave effect that's noticeable on still images, as if the set has bad filter caps, and they all have been replaced.. Putting the back cover on also throws off the ion trap.. Not sure why and how, it's not even touching the ion trap.. I did try and demagnetize the metal back cover with a degassing coil...

JR Tech that's what has been throwing me off, is L-23 because that coil is not in the same place, or not even sure it exists in this chassis... For some reason it comes in on channel 9 better as my modulators are set to 10... There's also a wave effect that's noticeable on still images, as if the set has bad filter caps, and they all have been replaced.. Putting the back cover on also throws off the ion trap.. Not sure why and how, it's not even touching the ion trap.. I did try and demagnetize the metal back cover with a degassing coil...

It would appear that the CRT was replaced at one time.
Air King products was owned by Hytron, the tube manufacturer. They all had Hytron CRT's in them. Maybe the original CRT had a single magnet ion trap, where the one that's in there now, might require a double ion trap. It's worth a try. I acquired a 12LP4 from a Philco, that only had a single ion trap. I left the ion trap on the tube as a reminder.

JR Tech that's what has been throwing me off, is L-23 because that coil is not in the same place, or not even sure it exists in this chassis...

To clarify, the way I read the schematic (page 2) in the Sams folder, L-23 *is* adjustment B-1 which *is* the Horiz Freq. control, which is the brass screw adjustment on the back of your chassis marked "AFC" and shown as "B-1, Horizontal AFC" on page 10 of the Sams.
Page 11 of the Sams clearly shows L-23 mounted on the back of the chassis near the focus pot, the location of adjustment "B-1".

jr

Does any have an extra ion trap? should I worry about the weak 12BH7 tubes and the weak 5U4? perhaps would these tubes be causing the excessive buzzing and hum bars? Can see the hum bars on a blank screen, which has to do with wave effect...

Hum bars, and hum in speakers can be power supply, 5U4 is power supply part,
You should really get the PS under control first, as everything else depends on it.

.

I've never worked on a set with a 5U4, but according to the seller, 5U4 tubes are either good or bad, no in between, and they don't test, or can't go by what the tester says.. It's not like I have the extra room and have these tubes lying around somewhere.. If that was the case I would have tried other tubes.. If it's a questionable tube, it would be something I would have to find on eBay or order from Orlando.. I don't want to order tubes that are already good... To be honest, I don't know where to start.. I thought of ordering 12BH7 and 5U4 tubes.. But I don't know..

Unless the 5U4 is the damper it should be easy to test. If it is the main B+ rectifier just check the B+ voltage....if it is within 30% of spec assume it is good.

Well, people say you can't go by the tester on those tubes because you
would have to know the unit's current draw, and be able to tell the tester to
show "good" at or above the current the tube is expected to pass......
So to best test the tube in your set, you should check the voltage at the first
filter cap, and see if it matches the sams....
You could cut the line off the cathode and check the current, is it within spec of what
the tube should be able to pass...? Use a scope, is there ripple...? Too much ?

You could cut the circuit out, put a resistive load cathode to ground ans see what the
voltage is with say a 5ma load on it, then put on the rest of the tv, and see if
there is too much drop driving the set.... It would be good to have a known good
5u4 to compare to, but you should be able to get a feeling for what's going on.....

Hum bars, open caps in PS, too much load on ps.

.

Well, people say you can't go by the tester on those tubes because you
would have to know the unit's current draw, and be able to tell the tester to
show "good" at or above the current the tube is expected to pass......
So to best test the tube in your set, you should check the voltage at the first
filter cap, and see if it matches the sams....
You could cut the line off the cathode and check the current, is it within spec of what
the tube should be able to pass...? Use a scope, is there ripple...? Too much ?

You could cut the circuit out, put a resistive load cathode to ground ans see what the
voltage is with say a 5ma load on it, then put on the rest of the tv, and see if
there is too much drop driving the set.... It would be good to have a known good
5u4 to compare to, but you should be able to get a feeling for what's going on.....

Hum bars, open caps in PS, too much load on ps.

.
Hum bars, could be caused by a cathode-heater short in one of the tubes used in the IF, video and tuner.
The so-called restoration, seemed to be done rather well and neatly.
My opinion would be, that the restorer wanted to bail out, as they couldn't get it working, just right.
The set, shouldn't have been that far out of whack, just by shipping it. :scratch2:

Hum bars and buzzing can be causes by your video source as well, older sets sometimes can't handle the strength of the signal from a RF modulator or VCR, try backing off the Contrast control a bit and see if that reduces the buzz in the sound.

I used a Blonder Tongue modulator wireless, and directly from cable box to channel 3.. No difference... At first it was channel 9 that was coming in better, now the tuner seems to give a better range on 10, where it's suppose to be with the modulator.. Adjusting contrast does help, but it's still very loud, sometimes even louder than the program.. It should be at minimal... The voltage checks I'll probably do sometime the end of the weekend, early next week..