A Confession

[Hagstar]

I did a postmortem on the tripler and it appears to have arced from the unused Focus voltage pin to the cage. I thought the distance, shrink tube, and 200K resistor in series would eliminate that risk, but.....

[Hagstar]

Better video- https://www.youtube.com/watch?v=LfC2...ature=youtu.be

[Hagstar]

Can someone offer clues as to why NONE of my horizontal phase coils seem to do anything? I can't seem to get any decent dynamic convergence and this appears to be the reason. The amplitude and tilt controls all seem to function normally. Stripped slug threads is my only guess.

John H.

[tom.j.fla]

If using a tripler with a built in focus divider, connect a 66 meg. H.V. resistor from the pot term. to ground, puts a load on the divider gets rid of arcs and you get a bleeder resistor on the H.V. All the best, Tom

[miniman82]

I probably have a few of those laying around if you need them. Also a few 100 meg ones, left over from the photo CRT experimentation.

[Hagstar]

Originally Posted by tom.j.fla

If using a tripler with a built in focus divider, connect a 66 meg. H.V. resistor from the pot term. to ground, puts a load on the divider gets rid of arcs and you get a bleeder resistor on the H.V. All the best, Tom

Thanks Tom. I believe you but how does this prevent arcs? Hair of the dog principle ? Bleeder resistor value principle I grasp....
EDIT - I see you must mean it would prevent arcing from the focus pin by providing a safe super high resistance path.

John H.

[Electronic M]

Originally Posted by Hagstar

Thanks Tom. I believe you but how does this prevent arcs? Hair of the dog principle ? Bleeder resistor value principle I grasp....
EDIT - I see you must mean it would prevent arcing from the focus pin by providing a safe super high resistance path.

John H.

Without the resistor the focus pin is at ~25KV and can arc to anything grounded within ~2-3"....With the resistor to ground that pin is at the designed value of ~4-6KV and probably won't arc more half an inch... That pin is meant to be the output of a voltage divider...Take away the bottom half of the divider and things go WAY out of design spec.

[tom.j.fla]

Tom C. thank you for clearing up my comment from post #50. I do better in face to face conversion, again thanks. Now if you loose the focus network in your CTC-4 use a 25 meg or maybe 50 meg focus pot from the control pin to ground and move the focus lead to focus pin on a tripler with the divider network built in, with a ECG500A use a focus control network from a CTC63 or CTC66 instead it has the top and bottom resisters built in. All the best, Tom

[Hagstar]

HOUSTON WE HAVE STABLE HIGH VOLTAGE AGAIN. Plus no blooming etc. with brightness control changes. A million thanks to this forum. "Neutering" the tire of the flyback last weekend took some worrying. Finally I just snipped through most of it and found the end again and unwrapped another couple hundred turns, securing the end in some shrink tubing and silicone.

This time I snipped off the unused Focus pin and buried the stub in a 1/2" mound of silicone.

One day I may find that NOS flyback but at least I have a working set and less hissing or to watch out for.....

John H.

[Phil Nelson]

Originally Posted by Hagstar

HOUSTON WE HAVE STABLE HIGH VOLTAGE AGAIN.

Pardon my slowness, but could you describe in a little more detail exactly what you hooked up and where? Might be useful for anyone needing to do this in the future.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[Hagstar]

Originally Posted by Phil Nelson

Pardon my slowness, but could you describe in a little more detail exactly what you hooked up and where? Might be useful for anyone needing to do this in the future.

Well as described early in thread I removed most of the old flyback "tire" (down to about 1/4") and insulated the loose end. This was tricky as it was too burned to unwind and that would take months- I clipped the tire deeply through all layers and found the end far down instead. Then I hooked up the tripler IN pin to the horz. output voltage terminal top of the assembly. The OUT is a thick insulated red wire- I soldered this to the terminal in the plexiglass cup beneath the high voltage rectifier. The REF(GND) pin I grounded. F (focus) will receive a 66 meg at 6000 volt resistor to ground to keep the voltage there sane. That's about it. The tripler fits easily with wire ties to the side of the high voltage cage.

John H.

[DaveWM]

used a tripler not a quadrupler correct?

[Hagstar]

Originally Posted by DaveWM

used a tripler not a quadrupler correct?

It was a tripler yes, of course this is not literal though. Triplers don't use 3 stages for TV use, this was a 6 stage and there are 5 stage ones also. The waveform from the horz. output is so uneven that's what's needed to multiply the voltage 3 times. A quadrupler would put it near 30 kV, well above spec 25 kV.

What I used- http://www.ebay.com/itm/112011512150

John H.

[DaveWM]

Curious, did you consider using the tripler supplied focus voltage for the set?

[Hagstar]

Originally Posted by DaveWM

Curious, did you consider using the tripler supplied focus voltage for the set?

I saved that option by leaving a stub of the pin. But I wanted to keep the set as original as possible and retain the separate focus diode.

John H.