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-   -   63 muntz vert sync problems (http://www.videokarma.org/showthread.php?t=251852)

chipper 08-13-2011 04:49 PM

63 muntz vert sync problems
 
1 Attachment(s)
I have done a total recap and replaced out of range resistors, but I think this is a vert sync problem, all tubes have been checked a number of times .

6GH8cowboy 08-14-2011 08:37 AM

Was this the problem before the recap? Check to see and possibly sub an electrolytic that may be in the circuit. Also there could be a integrator network in the works. Might look like a flat, dipped device with 3 or more wires. If there is a schmetaic? If you have it, you can duplicate the module. Didn't see too many Muntz TV's in the biz.

chipper 08-14-2011 10:55 AM

2 Attachment(s)
OK: No intergrator network in this set,and all caps are so far ok , I did check the vertical output and it checks out ok, the sams for this one is set 646/folder1Attachment 171314

Penthode 08-14-2011 01:04 PM

Is it possible for you to increase the resolution of the drawing? I cannot read it.

Thanks,

Terry

Don Lindsly 08-14-2011 01:04 PM

It looks like it is running off frequency. Try a few output tubes first. Check the plate resistor on the sync separator. Make sure there are no whiskers on any of the vertical controls and they all act as intended. Check component values for everything from the output plate, controls and looping back to the grid. That entire string affects timing.

Believe it or not; the vertical output transformer will cause poor sync. When all else fails, just replace it. It will cure weak vertical sync.

chipper 08-14-2011 04:44 PM

OK: Great, I do all those checks I am looking for a replacement vertical output , a sub for TO-0056 , gary at playthings from past say's a sub for this part is Merit A-4117, If anyone has one for sale please let me know??, stancor also made one but do not have the part #,thank for all your help, my pictures are not very good, need to get a good camera instead of cell phone also scans from my computer printer are not very good.

Don Lindsly 08-14-2011 06:17 PM

Merit would be my last choice. Cross to some other numbers or try for an original Muntz part. That transformer is critical.

The 2.2K and .022 make up the integrator. Measure the screen voltage for a fast check.

dieseljeep 08-14-2011 08:40 PM

Quote:

Originally Posted by chipper (Post 3011334)
OK: No intergrator network in this set,and all caps are so far ok , I did check the vertical output and it checks out ok, the sams for this one is set 646/folder1Attachment 171314

The 12AV5 tube might check out OK, but that circuit is very critical. All those sets came from the factory with GE or GE sourced Muntz branded 12AV5 tubes. I doubt the vertical output transformer is bad. As you can see, it's totally different from the transformers we're used to seeing. On the schematic, there's an extra secondary winding for feedback. Also it's not an auto-transformer.

chipper 08-16-2011 05:50 PM

Quote:

Originally Posted by Don Lindsly (Post 3011377)
Merit would be my last choice. Cross to some other numbers or try for an original Muntz part. That transformer is critical.

The 2.2K and .022 make up the integrator. Measure the screen voltage for a fast check.

OK Don: Are you talking about R-50 and C-37 at pin 3 of the 6BA8? thanks

Don Lindsly 08-17-2011 01:02 PM

I am using the Muntz factory schematic, not Sams. The numbers probably do not agree. They are the two components in series with the tertiary winding.

Also check the two 12K plate resistors on the 6BA8, pin 3.

Does the vertical hold control have any effect?

Don

chipper 08-17-2011 06:56 PM

YES: The vertical hold will hold the picture in place, but you still have the double image affect. the two 12k resistors ck ok, I checked the screen voltages at the neck of the picture tube with the set up and running for about 15mins. all check according to spec Except pin 4 sync sep, the spec shows a voltage reading of 70v but I get a reading of 170v on my meter.:scratch2:

chipper 08-17-2011 07:03 PM

Also wanted to add the this is not the original crt which was a 23CMP4(114 degree). the tube in the set now is a 23BHP4(110degree).

dieseljeep 08-17-2011 07:26 PM

Quote:

Originally Posted by chipper (Post 3011704)
Also wanted to add the this is not the original crt which was a 23CMP4(114 degree). the tube in the set now is a 23BHP4(110degree).

Don't worry about the difference in deflection angle. It might overscan a bit, but it has no bearing on the frame frequency.

DavGoodlin 08-23-2011 12:14 PM

Chipper:"The vertical hold will hold the picture in place, but you still have the double image affect."
Dave 63: Make sure you are not way off on the v-linearity and v-height adjustments if the pots do not have dead spots (whiskers). These controls will affect the frequency range of your V-hold. If you can stabilize the picture, but it is double, it is way off frequency.


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