Maybe I can rewind it with wire same size to 2.6 ohms. I could use a caliper to measure the wire diameter I have a focus coil which looks like the wire maybe a match I have another coil but the wire is to thin.

Good Afternoon,

I think rewinding that coil is not a good idea.... I think at this point you should think
about 2 possibilities. 1. The incoming burst signal is distorted because of a bad part,
or there is the other possibility, 2. A19 is not tuned to the burst signal..... I thought
about this a lot, and found stuff written about this group of circuits to refresh my
memory on every inch of these circuits. None of the circuit descriptions go into
"restoration" and replacing parts because they are believed to be out of
tolerance. So when you consider the large number of parts replaced in
this tv, I bet there are lots of circuits somewhat out of tune.

As of right now I have not seen a post where anyone has said A19 has been adjusted
for anything..... I wonder if that coil should be adjusted to see if it's out of tune and
causing the burst signal to be off by a little bit.

Back to A18, Timmy can you take that out and send us a good close up picture of it?
While I'm a fan of replacing parts that are out of spec, this one is only out of spec
as far as it's DC resistance goes..... You really need an Inductance Tester Gadget
of some kind to tell if it's Mili-Henry's or Micro-Henry's are out of whack, or not.
And wouldn't ya know it, Sam's don't give it's value.....

I would say, that if you really want to rewind that coil, make a new one, but
keep that one as is - for when the replacement don't work....

Timmy, I think over the course of this thread you said you have a color bar generator?
If that is true, it may be time to get it out, set it up, run it through the tuner, and
try adjusting the tv Color & Tint to show them as they should look, I think third
from the right is suppose to be magenta - Kinda like Purple.... I think you
should try and set this up and see if you can figure out if there is actually
a color - or several colors that are not being reproduced properly. And
with a color bar on the screen try and adjust A19, and see what
happens..... I would think turning it would kinda make the
color saturation go up & down as it's passing the burst...
So you would be peaking the coil for burst signal....

Possibility 3. This is all wrong..... Problem is in
some other part.....

..

And yes I have a bar dot gen and I tried adjusting A19 and yes it increases saturation however it did no good. Bar gen I cannot get any other colors on the screen other then the pic on the post. The tint adjust is very minimal at this point and the intensity it’s range is not right. So if the oscillator coil is supposed to be 2.6 ohms and this one measures almost 6 so in an oscillator circuit I would think this should be right. I really don’t want to rewind another coil it probably won’t be right but I maybe able to get a NOS miller and would hope it works if it’s the problem.

The resistance of the coil is not the most critical thing, it is the inductance. There are several possible reasons your coil reads higher resistance, none of them indicating a failure. Two I can think of:

1)SAMS has a mistake
2) The coil construction was changed sometime during the production run to use thinner wire or more wire with a smaller slug

Since the oscillator can be tuned to the correct frequency, both the coil A18 and the 15 pF cap must be OK. Stop fiddling with this section.

EDIT: repeat the AFC alignment if you have turned A18 since you did it.

Stop fiddling with A19. Go back to the AFC alignment procedure where you adjust A19 for greatest voltage (meter "deflection"). Do not ever change this again.

Please post some pix with the color bars showing the result with the tint control max CCW, centered, and max CW.

I thought A17 was for max voltage and the hue does not change any color in any position the bars on the pic in a previous post is the same for the most part it’s all red. Since doing the afc I have not turned A18.

I didn't think of this before because you said you have a good black and white picture, but just as a quick check, swap V20, V24, and V25 amongst each other. If color (or monochrome image) changes drastically, one of these tubes is bad.

I have already switched v24 and 25 and I have 1 known good tube I tried in all the sockets no change

Darn, i was really hoping we had found something here this time! :tears:

As i mentioned, one of the big problems with my RCA, was the same coil being 10+ ohms too high, which took me forever to find and fix. :scratch2:

Well I did a quick test with another 15pf cap and with the bar gen I had all kinds of colors flashing but I have to put it back so as it’s shielded but with the original cap nothing like this so I’ll see when I get it back. I have had mica caps go bad so what the heck why not try it

So there is no shelf life for 3.58 crystals. The ones I have are sylvania from 1983.

No. they are like Disc caps, they last forever, unless physically damaged somehow, or they get wet, etc.

.

https://www.researchgate.net/profile...ETHODOLOGY.png

Hope this works.... Ok. So Timmy, If you have a color bar generator that can put a pic like this on your
tv screen - can you please set it up and send a few pics of the screen with the color level set to display
enough saturation that we can see the color, and turn the tint knob to far left, Take a Picture, then
turn it 10 minutes then take another pic, then turn it 10 minutes, then send another pic, etc. till
you get to the far right. 10 minutes of knob rotation as if it were an analog clock face please.....

Please take the pictures with the camera right in front of the screen, not far off to one side, please
try & fill the camera's viewfinder with the tv screen so we can easily see how the colors are being
displayed on the tv screen..... Label the pics so we know far left - from - far right....

I know your camera can't upload to vk - send them directly to Yamamaya42 as you did before,
and then he can resize them & post them to his http://suzaku.live-evil.org site for us to see...
Please use that site as other image hosting sites I can't see because of my old computer....
Size should be 790px width auto for height, I believe these are within VK limits....

Thanks!


..

https://www.amazon.com/Digital-Video.../dp/B00005PJ70

useful, but bloody hard to navigate, the control menu is, interesting.

but it has EVERY thing you need to set up a TV.

I have to get the coil back in before anything and I have done this before I know the color bars but it’s still the same as the pic of the screen mostly red and with enough saturation the hue does nothing to change the colors on the bars at all.

Yes, A17 is adjusted for max in its step also. My point is to redo the color AFC alignment, then don't touch any of it while looking elsewhere for the problem.

.

I agree, decide which crystal delivers the best results, put it in, do the AFC
adjustment as in the Sam's Procedures, then tune A19 for the greatest
color saturation and leave all that alone... I also would like a good
picture of what you call "it's all red" And the color bar pictures.

Please...

.

I sent a quick video to yamamaya42

Ok I changed the 15pf cap and made no difference I get lock with the new xtal I can get lock with the old xtal but the adjustment is in a different place on the coil. If I run the adjustment in about 4 turns I get all colors jumping around and it’s not locked the video shows this but it’s back to normal lock but only has the one color if you go back maybe 2-3 pages the bar gen pick is what I still have. I did the afc AGAIN and no change.

unlocked color :O

http://suzaku.live-evil.org/IMG_1049.MOV

No I know it’s not locked the other pic I sent you is locked the video was if I ran the slug all the way in but it’s back where it was befor ,no advancement here still the same as that pic I sent you. I’m not even sure anymore here should I try to get another oscillator coil I don’t know since it locks and stable with no colors except in the pic.

This is very frustrating not finding anything wrong except the ohms of the oscillator coil wrong or not right colors yet it’s got lock. Did resistance check on v-20-25-24 all are very good. There was a voltage difference between 24&25 going to check again.

I’m going to put this project on hold I decided one way or the other I need to rule out the oscillator coil I have a supplier that may have this coil and a 15pf mica and the 27k resistor that makes up the whole coil and maybe he will have listed in the miller coil book if there were any production changes pertaining to this coil.

To repeat:

If you complete the AFC procuedure and have lock there is no more to be done in this section.

Please send some close-ups of the color bars with the tint control at both ends and centered and it may be possible to come up with some diagnosis. You have proven repeatedly that the oscillator is not a problem any more.

The hue only makes the color alittle darker or brighter the intensity further saturates more turning cw. I cannot post pictures since things were changed here on karma I did send a pic of what it looks like now to yamamam42 I can send a pic in an email without a problem. I have done the afc several times already as well. With the ohms higher then it should on the coil I don’t know if this would affect what colors would present.

If the oscillator is running and locked, adjusting it cannot cause the problems you are describing. There may be a problem in the hue(tint) control or something else may be misadjusted. Since you do not know how to follow the visual cues to the trouble, your description is insufficient for someone else to do so. Pictures are required.

I thought you found a way to send pics to yamamaya42 so he could post them.

I am sending you a private message to see if you can send them to me.

.


http://videokarma.org/attachment.php...5&d=1691979928


Ok, so I got the video that you guys posted, thanks! I can see the blue, red, & green
colors bars moving through the picture "barber pole" style. This is the burst color
not locked, or in sync with the local 3.58mhz color osc. I have labeled "A" in
my screen shot off your video.... I don't understand the vertical bars in
the picture..."B" Are they produced by the defect with this tv? Will
your signal source make the same bars on a different tv? If they
only show up on this tv..... What happens when you turn down
the color... All the way off to B&W....? Do they go away? If
those bars only appear on this tv, then I'm wondering if
there is possibly something wrong in the burst gate....
Does your color bar generator put some separator
between each color...?

Anyway, maybe it's a good idea to take a breather
from this project for a few days as you said....

To anyone who did not see the video, the blue,
Green, & red bars remain at that 30 degree
angle, but raise upward through the picture
continuously. The vertical bars labeled "B"
remain stationary, and are partially effected
by the colors passing by - as if they are
behind the vertical bars....


Night....

.

I was sent a Still pic, but it lacked any descriptive information, so I did not put it up, Old crystal, new? color up full or down, hue full CW/CCW/ or center, just the pics alone wont help much.


What are the status of things when taken?

So I hear the the grid resistors in the demods are super, super critical I don’t know what would be considered to high befor there is a color problem. It almost seems like only one demod is working. If there is no sign of any blue then I would think maybe a problem in v24 I did resistance check and found that pin 7 1.145k should be 1000k pin 7 399 should be 390 ohms.

The reading of 399 ohms which I will assume was on pin 8, ( you listed pin 7 twice ), is of very little concern, for its common to all Y amps, and comes from R205, and is in tol.

What should be of concern is if the resistance readings for pins 7 on V25/V24 are noticeably different, if they are, then BOTH the 68 ohms resistors should be replaced with a closely matched pair.

I just measured pin 7 on both one is 78 and 79 ohms

Timmy and I have been chasing his problem via email.
He once got good resistance readings on A17, but no more. Now reading multiple k ohms. Hard to believe that all three windings have opened up, but that appears to be the case. This would kill the blue demodulator.

He has a new A17 on order and meanwhile I have asked him to triple check the readings on A17.

If this fixes the missing colors, then we can proceed on finding the problem with the tint control.

There seems to be something very odd going on with this Motorola. :scratch2:

as for Tint, if L32 is bad, there is a replacement,

https://www.vivatubes.com/nos-nib-vi...id-8-2-uh-rfc/

as listed in SAMS.

Definitely in the The Twilight Zone with the development, if what he is reading is correct.

The only thing I can picture happening is, A17 was acting up from the start, and the cause of the old crystal to not work, or, something went VERY wrong when it was adjusted for maximum reading, like the entire coil turned, and tore wires perhaps?

Timmy's last voltage check of pin 6 V23 (PLATE) was at 189v, should be 220v, a tad low, from a 275v source, via a 8.2k resistor and through the 5.2 ohm coil, I would suspect if the coil was open when this was taken, it would be much lower than 189v? :O

We have since discovered that the A17 pin out is the opposite of what he thought and the coil reads good. Looking for opens/disconnects from the surrounding circuit.

In looking at your photograph it seems you are very close to zero beat on the oscillator. What is disturbing is the two horizontal bars at the top of the picture. If these are not a photographic anomaly I would be on the lookout for an open peaking (choke) coil across a plate resistor in the chroma, video & sync circuits. While many circuits work without these little buggers their absence passes high frequencies into the circuit causing undesirable output.

If you are having a problem with the Peaking Coils L37/L38, you can use Mouser # 652-9250A-105-RC , Should be close enough, I have these type in my GE, and they work well, but if u must replace, replace both!

Does anyone have a miller book to Motorola cross reference guide ? Can’t find it online.
Motorola number is 24D65948a04 and miller 6066 to Motorola number