yop, you can still find it, we use it all the time @ work.
https://www.amazon.com/Vaxxen-Labs-I...s%2C123&sr=8-2

Well I can’t use freez spray because it’s at the point that the color don’t sync at all now

I'm not going to reread the whole thread, but did you replace tubes or not?

Originally I did when the set was done and I since checked the tubes for the section for the color

Once again, you will be likely finding yourself up the creek without a paddle here (an oscilloscope), with very little to guide you in the right direction, for all you know, the IF could be acting up again, and annihilating the color sync information before it can be processed.

A good start that is IF you had a scope, would be to check the beat pattern going into V22, chroma phase detector, fed from the burst amp, this is what locks in the ref osc.

I can’t see how the IF could be the culprit it’s been fine I still have a good b&w picture still it gradually got harder for the color to sync up now it’s gone

https://hackaday.com/2018/01/18/know...ideo-waveform/



It's exactly what happened with with my CTC-16XL, I had color with direct input video, but not from tuner, a messed up IF WILL BLOCK color, cause the timings getting to the color circuit will be distorted, in my case, the 4.5 mhz trap was WAY out of tune, blocking all color, leaving a perfect BW screen, the IF on mine is still not fully right, but works well enough.

But yes, a borked IF can distort the colorburst signal timing, leaving just a BW screen, this can be tested by once again removing the 3rd If, and putting in direct video at test point B , as you have done in the past, if you see no color, then it's the color circuits, if you do, then is a problem before the color circuits.

The 41.25 trap was the big problem I had originally and never had to mess with the IF in the first place so I can try to tweak the trap and see.

It would be more advantageous to try to feed in video at point B first, with the 3rd IF removed, to try and localize the area of fault before you tweak anything.

I just turned it on cold and the color came in but if I turn the channel selector and back to 3 no color sync

Get out the freeze spray!

Does the line go from 12 - to - 6 ? Vertical line top to bottom? That's the transition
from Horizontal output tube to damper.... You know about that right....
Might not be much to worry about.......


.

Any ideas how to get a slug to move when they don’t move using a plastic diddle stick ?

Depends on the reason for it being stuck, if it's stuck due to wax or something of that nature, warming the ferrite core may get it free, but if the core is broken, or the tube it's in has degraded and swollen, there is no option other than to replace it.

As bandersen pointed out on U-tube, the older type brass metal ones were better.

The core is good it just looks like possible wax but with a plastic adjuster there’s only so much it can take before the adjuster breaks

The only way I can see to heat the core is with a pencil type soldering iron that would fit the hole it’s screwed into. I was going to bearly tweak the oscillator

What I have done before is taken the correct size allen wrench, and put it in the stuck core and heated the allen wrench, and applied heat to the stuck core indirectly, but by no means should one ever try to turn it with the allen wrench that will break it, only the plastic alignment tool.

No I wouldn’t use a metal Allen wrench I know they break like a cracker

On coils with thicker guage wire like H linearity coils I've heated the coil by connecting it to a D cell battery.

The fine guage ones like color and IF the Allen wrench heater sounds clever... Maybe add some heatsink compound to the end in the slug to improve thermal conduction to the slug.

The 41.25 & 4.5 traps are the only things you should tweak BUT
flag your stick to go BACK to start.......
I doubt it but if the set has AFT or AFC turn it OFF. That can cause
a channel to not FT on channel change. My rule is always turn OFF any
auto color / AFT while trouble shooting.

73 Zeno:smoke:
LFOD !

Well checking resistors not coming up with anything wrong so I went and tested tubes in the color circuit and all I found was the burst amp tube had some grid emission but as it heated up the grid emission lowered so I had another used one with no grid emission and now the color is syncing and if I change the channel momentarily I get the color bars again and then it seems to lock in on it’s own so maybe the problem here is tubes even though they test good it can’t be believed that they will work right.

About thermal related issues, like the original in thread (seems to be tube related as the last timmy's posting), I have sucessfully finally solved the the mystery of my Telefunken TV, using a electrical cleaner spray. I discovered (well, remembered... thanks to Electronic_M tip) this spray cooled surfaces, so I can try on this TV (when finally I had the time). One vertical output transistor reacted to it (thermally)(a TIP31), and, I discovered some hygroscopic resistor in series with the vertical centering control, and/or in the feedback arm... exactly what one I don't had the patience to discover; I changed all ones at the smalles area I can apply the spray (only 4 resistors). Super stable after this.

What’s the best grease or solvent to use on tube pins to help continuity. Or tuner spray?

Tuner/contact cleaner should be fine.

Contact cleaner will usually help. DeOxit is usually better. I like the brush-on
kind as its not messy.

I usually clean pins first with the green dish scouring pads.

Well it wasn’t tube pins one moment the color syncs just fine then the next day it won’t sync at all. I don’t know if the 3.58 xtal may have drifted a bit enough to keep the color from syncing.

You are dealing with an absolute here as far as the quartz crystal goes, it works, or it does not, it can not drift from it's designed frequency, any problems with the reference oscillator will be in the secondary or tertiary circuits of the crystal.

If there was a problem with the primary area of the crystal, it most likely would not be running at all.

What I have noticed is that the 6aw8 tube is exceptionally hot for only being on for less then 3 minutes and the color killer don’t seem to kill the color once it’s in sync. That tube is the color killer and tried another tube and the same result.

There is hardly any power on the triode part of the 6AW8A (killer), and little or no effect should be seen by turning color killer in color video, perhaps it may fade the color a bit, but drastic reaction should be seen with color fringes in B/W video, or fake coloring in snow with no signal.

V4 is also first video amp, a sharp- cutoff pentode, this part IS doing a lot of work, so getting hot fast is nothing unusual.

I just remember my other color sets with a color picture turning the killer counter the color disappeared.

And no I don’t have a scope so I guess it’s off again looking for bad resistors as I haven’t found not one bad one yet in the burst area, sync phase detect and chroma reference osc. So from here I don’t know where next.

If there is any doubt, replace with new 2% resistors, this will remove any chance of them changing value as the get hot/cold, even if they seem “OK” you can't account for how they will behave with temperature, pay vary close attention to R171/R172, these should be a matched pair, the higher the tolerance, the better, a matched pair will get you a more stable lock.

I do remember those 2 resistors and they were almost the same very little difference between them. What’s really odd is that the color seems to sync at random hot or cold now.

You do realize the color killers function is to look for the color burst in the recieved sync signal and turn the color off if there is no color burst in the recieved program, right?

There's basically nothing out there designed to send monochrome programming without a burst running* so the killer should naturally be in the color circuit enable state all the time.

* Some people with monochrome TVs will chop up a cable so they can take the luminance coax from the S-video output of a device and use that for burstless high resolution monochrome, but it seems pointless to do for a color set.

Just to re-enforce what EM said the Color Killer to basically a do-dad that turns off
the color osc, & other color circuits when you are watching a B&W tv show. It was
found that if those circuits were not turned off while a B&W show was on, it produced
annoying color effects outlining items, or characters on the screen. One way to
Properly adjust the color killer knob is to turn to a channel broadcasting mosquito
races and turn the color killer knob until the races are only B&W. When you
switch over to a color program, it should work as normal & you see the
program in full color. Mosquito races can be found on any analog channel
that has no programing being broadcast.

I did not see any confirmation that this is that same Motorola TS-907 that you
have worked on before, but I suspect it is..... If the Local color osc. does not
sync with the burst signal coming in on the tv signal, you will get that
"barber Pole" effect on the screen. You should look over at the V21,
V22, & V23 tubes & that area for possible troubles.....
As always, without a scope, starting off with
voltage checks is the best idea, If all is
well with that, you can always tweek
coils, but document each move
down to the smallest mm.
And try to put them back
if it don't get better.
Remember 6GH8
Tubes are trouble.



.

Mosquito races?

never heard it called that before! :D

https://media.tenor.com/_gjYF8Z41hcA...oltergeist.gif

Well this time I decided not to tweak any slugs because the color sync was fine just gradually got worse then lost it completely so at this point it’s got to be a cap or resistor so I’m still on the hunt. There is a 220pf mica at the 6gh8 oscillator maybe it has the mica disease if I can measure that cap maybe something is up with that.

The chances of there being SMD in the set is very very low.

Well it’s always a possibility since I’m still not finding any bad resistors and I already changed the caps.

Something in this circuit is not oscillating I would suspect a mica before a ceramic cap.