Re: DIY High Voltage Multiplier Thoughts or Suggestions
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It is labeled as ECG520 and it was an eBay item.? Only one available.? The seller listed it as a NTE538 equivalent and before I bought it I looked up the cross reference to be sure.? Yes, in the end I will work to have some sort of metal shielding around it as well as the part of the HV transformer which is now exposed.? I will try to document the process and post it in case others may be able to benefit from it.? The whole thing may take me a while to completely finish. ? ?
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From: Tom Jobe [mailto:tomjobe@...]
Sent: Friday, October 4, 2013 6:46 PM
To: TekScopes; Dan W. Dooley
Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions? So did you buy your multiplier as an NTE538, or not? My guess is that you want to have some?grounded metal surrounding the multiplier when you are all done with your modifications. ----- Original Message ----- Sent: Friday, October 04, 2013 4:34 PM Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions Yes Tom, ? Mine is quite different.? I had seen a few pictures on line and they looked like the one I have. ?Other sources, such as you have seen as well do not have an available picture.? This particular one is an ECG product but it does cross reference to the NTE 538.? I found that cross reference on line somewhere the other day.?? It was either the NTE site or the ECG site.? ? Anyhow, yes, it is rather different but I think I have found a way to get it to fit.? There is space against the chassis which is under the side circuit board which normally goes in this area.? I did some measurements and it will fit.? I have removed the fan which is defective so that leaves that space available.? I will not be able to put the small metal cover in place.? This is the cover which normally goes over the original multiplier and transformer.? I will figure a way to make it work. ? ? ? Look at the attached data sheet?for the NTE538,?which I believe came right from NTE some years ago. I think this is the model of multiplier Reed Dickinson used, and I think Reed is the one who told us about using it in 4xx scopes years ago. The few times I needed a multiplier for a 4xx scope I was able to find a used original part, so I never did buy an NTE538 and use it to replace the original. The NTE538 shown in this data sheet?is not even close to?the physical shape?of? the NTE multiplier?you have. NTE does not currently offer you a download of the data sheet for the NTE538, and the people I can find who?currently sell it do not have a picture of what they currently sell. I wonder if?your supplier or NTE?has?substituted another model of ?multiplier for the original NTE538, and?it just has the same?multiplier characteristics? Maybe Reed or another member will know the answer to this mystery if?you bought your?multiplier as an NTE538. PS Also attached are a few pictures of a 465B multiplier that I tried to mill the potting out of. The potting material quickly ruined a new end mill while removing just this little bit of potting, so something is very abrasive in the potting material. My plan was to?put together?a new multiplier circuit in the original plastic housing and then re-pot it. ----- Original Message ----- Sent: Friday, October 04, 2013 10:07 AM Subject: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions ? Unfortunately the new tripler is far too large to fit where the old one was. It will not fit into the space occupied by the old one even with the small metal cover left off. My suspicion is that those who may have installed the NTE538 in the past may have had something different than what the current packaging is about 3.5 inches long, and with the mounting flanges protruding out on both sides (where the screw mount holes are) is 4 inches wide. It's a little over 3/4 inch thick. There is literally no place inside the scope housing anywhere near the HV transformer area that this device will fit.
I am going to upload some photos of it.
The device I now have is ECG520 which looks just like the pictures I've seen of the NTE538 and cross references to it. The device is
--- In TekScopes@..., Reed Dickinson <reed714@...> wrote:
>
> The NTE538 or ECG538 voltage tripler will work quite nicely in 465, 465B
> 475, 457A scopes. Connect the D and LOW taps to ground and do not use
> the FOCUS tap. Cut the end off the original tripler and splice it onto
> the new HV lead. Use a thick plastic piece of tubing around the splice
> and fill with silicon to insulate it, make sure there are no sharp wire
> whiskers on the splice or you will get a corona arc. Drill two holes in
> the metal chassis where the old tripler was and mount the 538 with two
> screws. You might have to trim a little metal from the aluminum cover
> that covered the original tripler.
>
> Reed Dickinson
>
>
>
> On 9/24/2013 3:06 PM, wb5tka wrote:
> >
> > Since it appears that high voltage multipliers for the older scopes
> > such as the 465 are virtually impossible to find, does anyone have any
> > experience or thoughts on building one? I've heard of them being built
> > and I'm willing to give that a try but I don't know if the multiplier
> > in the 465 is 3X, 4X or whatever.
> >
> > Thoughts?
> >
> > Dan,
> >
> >
>
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