Sadly, if it doesn't work, adding resistors won't help- the transformer's magic comes from the # of turns of wire inside, not from the resistance of the coil; less resistance probably means fewer turns, unless the wire gauge is thicker than the original. (if you add a resistor, you make an RL circuit which behaves very differently from a coil by itself)

Also, if you can get replacement "magnet" wire [copper wire coated in enamel] of the same thickness as that of the original transformer (a yoke from a crap modern tube TV is a great place to get some), you could always give re-winding it a shot. It requires some patience and finesse, but it couldn't hurt to try if you can't get a good replacement for a reasonable price (i.e. reasonable hourly pay for how long you spend to wind your own), or are up for a challenge. It seems daunting, but it's not excessively difficult to try.

To do that, the two magic numbers you need are a) the # of coil turns, and b) the total length of wire. Both of these can be obtained while you unwind the original. As pointed out before, you also need to pay attention to the polarity (winding direction) of the original. If you can match the winding pattern of the original, even better! Note that if A number of turns does not use near B amount of wire then something's wrong and you need to try again, unless it's because you use a different winding pattern.

[I managed it with just matching the length of wire and winding pattern in an oscillator coil for my Fleetwood console (wire was ripped beyond repair, so I couldn't count turns and had to lay the pieces end to end to get length), and it worked... but I don't doubt a TV circuit is much more finicky, so YMMV]. I'd be happy to offer more details if you have questions... but no guarantees since I've only re-wound one coil myself, and that may just have been dumb luck!

I looked in my Merit catalog and they do list a replacement. It's an A-3003.

The A-3003 has a turn ratio of 1:4.2, the A-3006 that you have is 1:3.5.

www.oldradioparts.com has the A-3003 for $7.00. They have a $25 minimum order.

John

If it doesn't oscillate swap the leads on either the primary OR the secondary, but not both.

Tried the transformer and got deflection!
http://farm3.static.flickr.com/2049/...4b548680c8.jpg
I'm emailing oldradioparts now to enquire about the correct transformer. Does any one else need any parts and want to go in with me to meet the $20 minimum order? I suppose I could always just give them $20 for the transformer instead of $7.

You might look at his book and magazine section. You might be interested in some of the TV related ones.

It might be a while until I get my hands on the correct transformer so I was thinking about working on another problem I have with the set. The picture above was taken from a side angle so it's not as obvious as when you look straight on at it, but the picture is skewed to the right and not level. Can any one point me in the right direction towards a fix for that? Is that something that I can work on now, or should I wait until I have the transformer and a full height picture?

I found another Majestic on Craigslist in my area with the same deflection problem...I wonder if that is a common thing with these sets.
http://pittsburgh.craigslist.org/atq/2380646109.html

I'd hold off until you have a new transformer. I've seen a few other threads here where people had no vertical, and the line often looked a bit skewed.
Once you have an actual picture, you can then display a test pattern/grid to aid in adjustments, and do all of the convergence/purity stuff in one swoop.

If memory serves, you can "rotate" the picture by rotating the entire convergence assembly , as that will adjust the directions that the magnetic field deflects the beams.

There are usually a set of rubber wedges under the yoke to keep it from moving. You should mark their positions before you remove them, otherwise your centering will be off when you reassemble.

Here's an interesting read while you wait. This discusses purity adjustments on newer colour CRTs, but the principles behind it still hold. http://personalpages.tds.net/~rcarlsen/cbm/converge.txt

Besides Playthings of the Past, it might be worth contacting Moyers.

I agree with VintagePC that you should wait until you have the vertical working.

I found a Stancor a-8122 locally, it's a vertical blocking oscillator transformer and has a turn ratio 1:4.2. Any one venture a guess if it'll work?

Should do the job. The turns ratio that is key to the magic that makes it work.

The only thing you may run into is the polarity (I suppose "phasing" is a better term since we're dealing with AC) - if it doesn't work, reverse the leads to one of the two sides and try again.

I don't know what would happen if you got the phasing out of sync here - If it's part of an oscillator, then it probably wouldn't oscillate, but since it's part of the vertical section, you might also end up with an upside-down picture :D (either way, it's a "safe" mistake - things won't go bang if it's wrong)

Vintagepc, I believe that this is not a color TV so it should not have purity or convergence adjustments.

Whoops... 's what I get for posting/following several threads at once :)

Heh.. I was kinda wunnerin' how the saga was gonna play out.


:smoke: oc(Bill)

Got the new transformer in the set and it gives deflection but not a full picture. It did bring the horizontal picture back to the center again. Even though it was not a full height picture it did for the first time look "correct." It might be because I could see scan lines for the first time, or because the picture was horizontally aligned, or it could just all be in my head. I did try adjusting the vertical hold control, the vertical linearity control, and the vertical size control, all to no avail. The transformer I used was a Stancor model a-8122. The turn ratio was 1:4.2. The primary and secondary impedance was a bit different on the replacement than the schematics showed on the original. The original was 160 and 1,300 and the replacement was 170 and 940. Could the transformer still be the problem or is it time to look elsewhere?
http://farm4.static.flickr.com/3552/...246a054379.jpg

Do the vertical controls do absolutely nothing to change the bar, or just that they don't get it to a proper height?

You don't mention it, but I assume you tried the lead swap on one of the transformer windings to check if the phasing was right?

If you did, it's probably time to start looking elsewhere; you've got "partial" vertical, as opposed to flat-out no vertical. That would suggest an out-of-spec component - time to start ohming out the resistors in, and before, the vertical section to see if any have gone high if you haven't already done so. If those all check out fine, then it can shift the focus back to the transformer; less of a headache that way than trying to source an exact match and finding it still doesn't work.

Are you able to borrow or access an oscilloscope? Those can come in handy when trying to figure out the problem, since the actual shape and tracing back of the waveforms can point to the cause relatively quickly (i.e. if the problem is caused by the vertical section, or the result of something before) ... but it can be done without.

Honestly I hadn't tried swapping the leads on the transformer. I guess my assumption was that if I wired it incorrectly that I would have no deflection at all. I'll try that first tonight. Thank you for taking the time to point out the painfully obvious, sometimes(hopefully THIS time) it helps.

Only because it happened to me when I re-wound the coil on my own radio. It didn't work well at first (though I could hear the output of a spark gap transmitter), but swapping the leads made a world of difference... so it's my mistake that you're learning from :)

Switched the leads on the secondary of the transformer and it had little effect. The vertical was the same size. The only difference was the image was again shifted to the right of the screen. I switched the leads back and the image was centered. I did take v13 to a shop to test it and it passed, although the guy admitted that he hadn't used his tester in quite some time so it may have been way out of calibration. There is another shop in town that I know I can trust if I take the tube there to test it so I may do that. He may be able to give some advice if it passes, and sell me another one if it fails. If every thing checks out there it's time to move on.

I do have access to a scope btw so if there is some tests I can run with it to narrow my search down before I start checking every capacitor and resistor that would be fantastic.

It would have been too good to be true if it had worked :)

I don't have a scope myself, but often the service manuals (Sams or otherwise) will have diagrams showing what the waveform should look like at various test points in the set.

If you don't have that, then perhaps someone more familiar with the waveforms that should be there can point you in the right direction for where to test and what it should look like.

If the v. controls do absolutely nothing, then I'd check those as well before going resistor-hunting... Sometimes dirty pots can cause weird problems.

Your Sams doesn't include model waveforms for the vertical circuits, unfortunately.

It does include a voltage chart. You can use a voltmeter to check voltages on V13 and V14 and then compare them to the voltages given in the chart. If you find one that's way off, you can then check the components in that neighborhood. Put one hand in your pocket when touching the voltmeter probe to anything on the live chassis.

Also double-check your previous work, making sure that you (or a previous handyman) didn't miswire a replacement capacitor, drop a blob of solder somewhere, or accidentally nudge some component so that it creates a short circuit. Even experienced restorers slip up every once in a while.

Phil Nelson

On top of that, if you have alligator clip leads or test leads, I like to connect one end to the test points before I power up the set so there's less danger of a slip-up with the probe- it's just clipping and unclipping the other end(s) safely away from the main part of the set.


Also, on top of the one-hand-in-the pocket rule: if you have electrically insulating rubber gloves, put on one (or both, if you can work with them) just in case you forget and do take that hand out of your pocket.

Safety first - Voltage hurts, current kills... and your body's resistance is futile. (Sorry for the pun... I'm terrible with them :D)

To the OP:

At this point, and if you still have access to the variac, you might consider trying this:

Disconnect both primary leads of the vert.out transformer and drive it directly with the variac. Granted it's a sine wave instead of sawtooth, but will tell you a lot. You should get very robust deflection, probably at around half to full line voltage. This will tell you the tranny and yoke coils are good, thereby proving the fault lies somewhere "upstream" of the tranny.

If the problem remains, it's gotta be either in the tranny or the yoke (like a shorted turn that won't show up on a resistance check). Now disconnect the yoke winding and drive it directly with the variac (starting from a low setting). If deflection comes up, the yoke is good and by process of elimination, the fault would be in the tranny.

Of course if the fault is "upstream" all bets are off. The first place i would look is the plate load resistor of the vert.oscillator, if you haven't already checked it. I can't see it since i don't have the schematic of your set, so this may not be applicable. But in many sets that resistor is a very common failure and worth bookmarking*. Its value goes 'waaay high due to being hammered by a high level pulse. Bill(oc)

*Germaine to all makes and ages of '50s-'60s tube sets.

Awesome suggestion! Thank you so much, I'll try this as soon as I get in front of the set again.

BTW- What is The OP?

I think I need to back up and run a test that I don't think I did right before. I want to test the deflection coils to see if my problem is there. In the picture of the schematic below I tested continuity across the yellow wires. I'm not sure if that was right. I think I need to test across the red, and across the blue to test each coil. Can any one confirm that? If that is indeed what I need to do then my next problem is that I don't know how to test the two coils independently of each other. I apologize for leaning so hard on all of you to help me get this sucker up and running, but we all have to start learning some where I guess.http://farm3.static.flickr.com/2148/...1fd58f051e.jpg

Looking at your picture, what you'd want to do is as follows. This will ensure you've tested the coils:

1. Disconnect/desolder the ground connection at the lower yellow arrow. (this ensures you test the coils themselves and not an alternate current path - note the other yellow arrow traces through the transformer and also to ground, resulting in two possible paths for the current to flow when you measure any two points in that line.)

2. Measure across the blue arrows.

3. Measure across the red arrows.

4. Reconnect the ground connection from step 1.

It looks like you have resistors in parallel with your coils in the schematic. If that's the case, the resistance you measure should be 1/measurement = 1/(coil resistance)+1/(resistor resistance). Keep in mind the coil will have a fairly low resistance, so the reading is probably only a handful of ohms.

With both resistor values the same, the red and blue measurements should be identical.

If you measure anything different than expected, you'd need to disconnect one lead of the resistor to determine the culprit (coil or resistor)

I'm good on the points you mentioned above. My problem is that I don't know where on the actual set itself is in between the two coils. It makes sense on the schematic but I can't transfer that to the set.

Hmm... it might well be an inaccessible direct connection between the coils in the yoke itself. If that's the case, the best you can do for steps 2/3 is test across the yellow arrows. the result can indicate if coils are open. It won't indicate shorts because of the parallel nature of the circuit.

The AC/variac drive test mentioned above will give better information as to the state of the coils, since you get a visible result... If it does indicate a problem in the coils, the test I described would help narrow it down.

The connection is most always inside the yoke housing.
Yep, but he's gotta disconnect one end, either the ground end as you suggested, or the top end. Doesn't matter which. While it's disconnected is a good time to also check continuity of the secondary winding of the transformer.
To the OP (original poster): is the capacitor across that winding (shown with dotted lines) actually in the set? If so, have you replaced it and/or verified that it's not shorted?
oc

Looking at the schematics I see that both coils are 2200 ohms. If I meter on my yellow arrows am I correct in thinking that it should be 4400 ohms?
The secondary of the transformer is good.
The third question about the capacitor across the winding in the schematics I cannot answer. I didn't see that before you mentioned it. It says that it's 75mmf, but it's not listed in the part list. Could that also be located inside the yoke housing?

Not quite - the schematics show resistors in parallel with those coils, and those resistors are each 2200 ohms. (Look at the horizontal coils - there's no resistance marking/parallel resistor).

The only time you'd read ~4400 ohms is if both coils are open.
If you read ~2200, one coil is open.
If you read something closer to zero, then the coils are probably OK (but you can't infer anything about the state of those resistors - see my parallel resistance calculation in the previous post).

BTW, if you can see those two resistors sticking out of the yoke or anywhere on the chassis, it gives you some test points for your red/blue arrows.

It's possible, but doubtful. The easiest way to find it is to carefully trace the entirety of that vertical deflection line which your arrows point to and try to locate it. If you can't find it, you can do a test to see if it's there- disconnect BOTH ground points at each end of the line, and apply a few volts (no more than 20) AC to the line. (it will float, since it's not grounded at either end).
Then, see if some AC appears on the chassis ground. If so, that capacitor is hiding somewhere and passing AC (or it might be shorted). If not, it's probably not there.

Also, look at the connections running in to the yoke - there should be 4, two for vertical, and two for horizontal. (You may see only 3 if the lower ground is directly accessible from the yoke.
If you see more/fewer, it may indicate additional components have been hidden... try to trace them on the schematic to find out what those wires do.

Since the 75mmf is inside of the dotted line for the deflection yoke it would seem that it is part of the yoke. Unless I'm looking at the wrong 75mmf.

My understanding is we're talking about the one above his upper yellow arrow. The one you refer to is part of the horizontal circuit, whereas we're diagnosing the vertical :)

Old Coot- Are you referring to the capacitor just above the dotted lines indicating the yoke in my picture? The schematics say that it's C70 and rate it at .25mmf at 200v. The thing is I can't find it on the schematic pictures of the top and bottom of the set that indicate where everything is. Jeyurkon maybe you can confirm that?
The schematics make me think that the capacitor would live at the end of the right hand yellow arrow in the picture below.
http://farm4.static.flickr.com/3641/...d0c8f076c8.jpg
As you can see there is nothing there but a termination point for the wire coming from the secondary of T4 and from the vertical coils. I had mentioned this in an earlier post and postulated that maybe it was just there just to make my job easier. Is it possible that it is just missing from the set? That seems improbable to me.

To what are those two little "domino" looking things connected? (hiding behind the big resistor that's dead center.). Those are mica capacitors, and it looks like they have one lead on the left-hand connector to which an arrow points.

Also, if that orange-brown square with three leads coming out of it is connected to anything relevant, beware that those are usually a package containing a resistor and capacitor network. It doesn't look like it's attached, but just something to keep in mind. Some schematics show the separate components, some show a "magic box", and others will show the internal components outlined with a dashed-line box.

It's also possible that that capacitor is hiding somewhere in the yoke, especially if there's a nearby accessible ground point to which they could run it... It could well be bridging BOTH deflection coils to the ground connection on their other side.

Since most capacitors short on failure (unless they're special line safety caps), the AC test I mentioned will show if it's present regardless of condition... and at least knowing that eliminates some of the guesswork.

The parts list has an asterix next to C70. "Not used in all models." Also a note symbol and dotted line in the schematic.

Phil Nelson

We'll there you have it. I guess my model is part of the exception.

Thanks, that explains my confusion. That one is actually 0.25 uF, or would be if it were used.

I should have paid more attention and noticed that the discusion was about the vertical.

I took an early day at work to spend some time on the set tonight. I also read through this entire thread a couple of times to come up with a game plan of tests for this evening. Here is what I'm thinking.#
I'm going to recheck the vertical height control selector.#
I'm going to check voltages on v13 and v14. I will connect my lead clips to the set and to my meter, then fire the set up for a measurement. After taking a measurement I'll remove power from the set and move on to the next voltage measurement.#
I'm going to disconnect both primary leads on my new t2 and connect them to the two leads on my variac. I'll fire the set up and turn up the variac to line voltage or robust deflection, which ever comes first.#
If deflection does not occur I will move on to OC's next suggestion of driving the coils directly with the variac. On this test I'm a bit hazy on. There is only one lead from the yoke on the vertical side. What would I do with the other lead on the variac?
After completing those test if I have time I'll move on to more.#

The other side of the vertical is connected to ground according to the schematic (most likely chassis ground somewhere.)

you _SHOULD_ be able to connect the neutral side of the variac output (Be careful that you do really have neutral!) to the chassis, and then the HOT side to your coil wire.

HOWEVER, before you do that, double-check that your chassis is actually grounded or connected to line neutral. If your set has the possibility of a "Hot" or floating chassis voltage (i.e you do NOT read close to zero volts when measuring voltage from chassis to neutral in the wall plug), DO NOT DO THIS - it could trip your breaker!

Since you know the transformer is good though, if driving it with the variac produces no deflection, you can be almost certain the coils are the problem... and the test you're unsure about will produce little extra information.

Taking off early to spend time on the set turned into run errands time :sigh: I was able to do a voltage test on V13 and V14, however.
My results:
V13 according to the schematics should read- Pin 1: 170 to 40VDC. Pin 4: 6.3VAC. Pin 5:170-40VDC. Pin 6: -40 to -2.4VDC.
V13 actual readings- Pin 1: 51 to 20VDC. Pin 4: 7.5VAC. Pin5: 51 to 20VDC. Pin 6: -1.21 to -.97VDC.
V14 according to the schematics should read- Pin 3: 260 to 230VDC. Pin 4: 260 to 230VDC. Pin 6: 215VDC. Pin 7: 6.3VAC. Pin 8: 30 to 8VDC.
V14 actual readings- Pin 3: 350 to 300VDC. Pin 4: 445 to 230VDC. Pin 6: 295 VDC. Pin 7: 7.5VDC. Pin 8: 49 to 12VDC.

V14's readings are a bit high, but could those be within tolerance? V13's readings are low enough that I can't imagine they would be within tolerance. V13's readings on pins 3,4, and 8 change with the adjustment of V4a(the vertical size control). Schematics call for resistance of 2.5meg which is right what it metered to. I mentioned before that I wanted to change V13(a 6C4) but I haven't done that yet.