Motorola roundie

[old_tv_nut]

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.

[doogie812]

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.

[Yamamaya42]

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!

[timmy]

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

[Yamamaya42]

Originally Posted by timmy

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

https://worldradiohistory.com/Archiv...Catalog-59.pdf

[timmy]

Originally Posted by Yamamaya42

https://worldradiohistory.com/Archiv...Catalog-59.pdf

I went over that page it don’t show Motorola numbers crossing to miller

[timmy]

Motorola number to miller number

[Yamamaya42]

If you are sure that L34 is the problem, it's going to be a real pain to replace because an exact replacement it most likely unobtainable, the best way forward would most likely be to use a replacement coil from an RCA type that uses the same 6GH8A osc circuit, and find a coil that is rather close in resistance to what was in there originally, then compensate for the difference with the secondary components like slight changes in the 15pf cap and or the 27k resistor.
It will take trial and error to get right.

[timmy]

Originally Posted by Yamamaya42

If you are sure that L34 is the problem, it's going to be a real pain to replace because an exact replacement it most likely unobtainable, the best way forward would most likely be to use a replacement coil from an RCA type that uses the same 6GH8A osc circuit, and find a coil that is rather close in resistance to what was in there originally, then compensate for the difference with the secondary components like slight changes in the 15pf cap and or the 27k resistor.
It will take trial and error to get right.

I can get that coil but befor I do I wanted to make sure it matches the Motorola number. I actually don’t need the coil this one is fine just want a spare just in case as I may never need it at this point.

[Yamamaya42]

is your color working now?

[timmy]

Originally Posted by Yamamaya42

is your color working now?

Yes the color is working great now but if I had noticed certain things early on and had this problem before I would have been better ready to fix this problem from the beginning. It all started with a leg of a cap that was just bearly touching the point G for the afc it grounded a .01 how this moved to create this short I don’t know. Old tv nut had lots of patience but he nailed it when I told him what G was measuring to ground but by that time we went over EVERYTHING.

[Yamamaya42]

So, the problem was in the L31 can? :O

[timmy]

Originally Posted by Yamamaya42

So, the problem was in the L31 can? :O

It turns out there was no problem in any cans the only confusing thing was checking resistance on these cans going by the sams but it turns out that the wiring of these cans was upside down shown on the sams until I decided to check the other way around only to find they were ok.

[Yamamaya42]

So, basically the color AFC attempts failed at first due to procedural error, and or not fully understanding the rather convoluted directions in the SAMS, which is no surprise.

[timmy]

Originally Posted by Yamamaya42

So, basically the color AFC attempts failed at first due to procedural error, and or not fully understanding the rather convoluted directions in the SAMS, which is no surprise.

I guess you could say the afc attempts failed because I never had a problem like this so Grounding point G I would not have known what was right or wrong. So the coil may show 1-2 on sams but it was actually 3-4. At least I was able to figure that out lol.