#46
|
||||
|
||||
Quote:
John H. Last edited by Hagstar; 06-26-2016 at 06:49 PM. |
#47
|
||||
|
||||
Here's the diagram of the NTE523 I used, I did order a 500A replacement, actually a bit cheaper.
|
#48
|
||||
|
||||
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.....
|
#49
|
||||
|
||||
Quote:
|
#50
|
|||
|
|||
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
|
Audiokarma |
#51
|
||||
|
||||
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.
__________________
Evolution... |
#52
|
||||
|
||||
Quote:
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. Last edited by Hagstar; 06-29-2016 at 04:58 PM. |
#53
|
||||
|
||||
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 C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#54
|
|||
|
|||
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
Last edited by tom.j.fla; 06-30-2016 at 09:22 PM. |
#55
|
||||
|
||||
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. |
Audiokarma |
#56
|
|||
|
|||
Curious, did you consider using the tripler supplied focus voltage for the set?
|
#57
|
||||
|
||||
Quote:
John H. |
#58
|
|||
|
|||
understood. Now you need to post a pic or better a video of the working set!!
|
#59
|
||||
|
||||
Quote:
http://hagstar.phanfare.com/7138833 John H. |
#60
|
||||
|
||||
So when I did check the high voltage with the new tripler what is it? 22 thousand volts, just like before. It's stuck on that value. Does anyone get a 25 kV out of these? Not that it seems to matter too much.
But I do have to add a bleeder to stub of the focus pin- it manages a bit of corona for a moment under the RTV blob covering it to the cage as is, have 66 meg resistor coming. John H. |
Audiokarma |
|
|