Date   

Re: Enough of NEO and goodbye

 

I fully agree with Albert. I hope someone finds a good solution and we see you back again.
 
Tom
 

----- Original Message -----
Sent: Sunday, October 06, 2013 12:50 PM
Subject: [TekScopes] RE: Enough of NEO and goodbye

 

I for one really regrets your decision to leave the group Steve! Anyway, thanks for the very informative messages from your hand.

Albert



Re: Enough of NEO and goodbye

Albert Otten
 

I for one really regrets your decision to leave the group Steve! Anyway, thanks for the very informative messages from your hand.

Albert



Re: Enough of NEO and goodbye

micoderup@...
 

I agree Steve,


We need to go to a google group. A retirement group to which I have belonged for 10 years has moved to Google. That solved the problems. Yahoo is falling apart and we should not have to suffer the consequences.


Michael 



---In tekscopes@..., <ditter2@...> wrote:

While I have really enjoyed contributing and reading from the groujp over the past few years, I simply don’t have the time to put up witih the inefficiencies of the NEO screw-ups and will be leaving the group.

 

A note to the moderators – there has been a lot of discussion on moving the Tekscopes group to another forum, but nothing has happened.  For the members who wish to stick with it, I would recommend you make this change.

It is no secret that Yahoo continues to be in financial trouble, and ill attempts to turn it around such as neo are alienating their users, further accelerating their death spiral.  I suspect they will be bankrupt within a year or two.  It would be good to have archived the mail list to preserve it for a possible move, or better yet, make it before Yahoo goes under.

Best regards to all,

Steve


Enough of NEO and goodbye

ditter2
 

While I have really enjoyed contributing and reading from the groujp over the past few years, I simply don’t have the time to put up witih the inefficiencies of the NEO screw-ups and will be leaving the group.

 

A note to the moderators – there has been a lot of discussion on moving the Tekscopes group to another forum, but nothing has happened.  For the members who wish to stick with it, I would recommend you make this change.

It is no secret that Yahoo continues to be in financial trouble, and ill attempts to turn it around such as neo are alienating their users, further accelerating their death spiral.  I suspect they will be bankrupt within a year or two.  It would be good to have archived the mail list to preserve it for a possible move, or better yet, make it before Yahoo goes under.

Best regards to all,

Steve


Re: 7T11 in 7854

sander.slang
 

After some more checks I suspect the -50V line. There is only -0.6V on the -50V supply and the current is -190mA. At the moment I am searching for capacitors in on this supply. 

On 01 Oct 2013 20:01:15 -0700, you wrote:

>Sorry, but no. Those Ta caps in the axial-leaded cans in the second picture are NOT wet-slug types - they are as dry as dust inside. They are made of the same solid sintered Ta compounds as the epoxy-dipped style ones, but are hermetically sealed with glass-insulated end feedthroughs soldered to the can rims, and the positive lead is soldered within a steel sleeve bonded to the glass, so they are much more reliable. These are my favorite kind of Ta caps for all applications within their ratings, which limit out at about 35V.
>
>True wet-slug types use a rubbery elastomer seal and are not hermetic - the solid Ta wire from within passes through layers of teflon and elastomer, and is butt-welded to a steel lead to make it solderable. There is also a crimp around the can rim at the positive end where that lead comes out, to pinch the seal tightly, to (usually) keep the liquid sulfurc acid electrolyte inside. This is the weak link - the seals sometimes leak and let the acid out, causing all kinds of mayhem on the outside. These caps may be rated up to about 150V and 125 deg C, which the solid dry ones can not achieve. For an example of these, look inside a 7A13 - there are two wet-slugs (if they haven't been replaced with Al types) used as bypass caps on the plus and minus 50V supplies.
>
>The timing caps in the first picture are indeed Tek-made hermetic plastic types, all matched, being code "F."
>
>Ed
>
>---In TekScopes@..., <tekscopes@...> wrote:
>
>Here is a photo of the A1 logic and A4 interface side of the 7T11A showing
>matched capacitors in the lower right corner which are *not* wet slug tantalum
>capacitors:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_A1_Logic_and_A4_Interface_Board_Side.jpg
>
>Here is a photo of the A3 trigger board side of the 7T11A showing a number of
>wet slug tantalum capacitors including C810 at the center right side beneath
>connector P101:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_A3_Trigger_Board_Side.jpg
>
>Here is a scan of the A3 trigger board layout from my 7T11A manual (070-6176-00
>Revised NOV 1989) which clearly shows C810:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_Figure_8-3_-_A3-Trigger_Circuit_Board_Assembly_-_300dpi.png
>
>Note that I had to disable hardware accelleration in Firefox for it to display
>high resolution images.


Re: 7T11 in 7854

sander.slang
 

In the mean time I hooked-up the current probe and TDS3032B oscillscope to all supply channels and measured the current during start-up and when it is clamping.

 

A36= ~0mA

B35=~0mA

A19=+20mA (ripple on the signal)

B19= -190mA

A18= +60mA

B18= -8mA

B10= ~0mA

A9= ~0mA

A8= +230mA

I also hooked the clamp over other signals but all very low currents.

 

Are these currents normal in clamped mode? Any advice what to do as next step? Nearby the edge connector are also several axial Kemet capacitors. Is it better to replace them?

On 01 Oct 2013 20:01:15 -0700, you wrote:

>Sorry, but no. Those Ta caps in the axial-leaded cans in the second picture are NOT wet-slug types - they are as dry as dust inside. They are made of the same solid sintered Ta compounds as the epoxy-dipped style ones, but are hermetically sealed with glass-insulated end feedthroughs soldered to the can rims, and the positive lead is soldered within a steel sleeve bonded to the glass, so they are much more reliable. These are my favorite kind of Ta caps for all applications within their ratings, which limit out at about 35V.
>
>True wet-slug types use a rubbery elastomer seal and are not hermetic - the solid Ta wire from within passes through layers of teflon and elastomer, and is butt-welded to a steel lead to make it solderable. There is also a crimp around the can rim at the positive end where that lead comes out, to pinch the seal tightly, to (usually) keep the liquid sulfurc acid electrolyte inside. This is the weak link - the seals sometimes leak and let the acid out, causing all kinds of mayhem on the outside. These caps may be rated up to about 150V and 125 deg C, which the solid dry ones can not achieve. For an example of these, look inside a 7A13 - there are two wet-slugs (if they haven't been replaced with Al types) used as bypass caps on the plus and minus 50V supplies.
>
>The timing caps in the first picture are indeed Tek-made hermetic plastic types, all matched, being code "F."
>
>Ed
>
>---In TekScopes@..., <tekscopes@...> wrote:
>
>Here is a photo of the A1 logic and A4 interface side of the 7T11A showing
>matched capacitors in the lower right corner which are *not* wet slug tantalum
>capacitors:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_A1_Logic_and_A4_Interface_Board_Side.jpg
>
>Here is a photo of the A3 trigger board side of the 7T11A showing a number of
>wet slug tantalum capacitors including C810 at the center right side beneath
>connector P101:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_A3_Trigger_Board_Side.jpg
>
>Here is a scan of the A3 trigger board layout from my 7T11A manual (070-6176-00
>Revised NOV 1989) which clearly shows C810:
>
>http://www.banishedsouls.org/c2df3757f1/7T11A/7T11A_-_Figure_8-3_-_A3-Trigger_Circuit_Board_Assembly_-_300dpi.png
>
>Note that I had to disable hardware accelleration in Firefox for it to display
>high resolution images.


Re: DIY High Voltage Multiplier Thoughts or Suggestions

Garey Barrell <k4oah@...>
 

THANKS!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

mst3krules@... wrote:



Got the scanner working. Th file is in the Files section as ECG High Voltage Triplers.



---In TekScopes@..., <tekscopes@...> wrote:

I'm interested!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

mst3krules@... <mailto:mst3krules@...> wrote:

>
>
> I found some data on the ECG high voltage triplers if you are still interested.
>
>
>
> ---In TekScopes@... <mailto:TekScopes@...>, <tekscopes@...
<mailto:tekscopes@...>> wrote:
>
> Well, well, perhaps I've got it. Not finding any documentation on the ECG520 anywhere on line but knowing that it
> cross references to the ECG538 (which also seems to be lacking in documentation) and so on, I had to do some
trial and
> error connecting. Connecting the "C" line, which I had assumed meant "common" or ground and that showing no
success, I
> tried the other connections. "Low" and "Focus" and the three in combinations. With C connected by itself or in any
> other combination, there is no high voltage. With Low and Focus still connected (I had just disconnected the C
> connection) I got the -2.4 KV on the HV TP but also with a high pitched whine which is probably the HV oscillator
> running hard. Removing the Focus lead leaving only the connection to Low, the unit works. I measure -2.4 KV with no
> audible whine. My ears are good but I should not be able to hear 50 kHz :-)
>
> I briefly touched the end of the connector which is the HV out to the CRT with the end of the HV probe and it was
> obvious there was a very high voltage there with the "buzz" but I did not leave it there long enough to see just
what
> the voltage is. I may have another look but I would presume somewhere between 7 and 8 KV. Does that sound right?
>
> Anyhow, now my next challenge will be to find a way to fit the new multiplier somewhere in the vicinity of the old
> one. I've got some ideas but will need to think about it a bit more.
>
> Thanks all for the help and suggestions. I'll do some more photo documenting when I get the device mounted.
>
>
>
> -- In TekScopes@... <mailto:TekScopes@...> <mailto:TekScopes@...
<mailto:TekScopes@...>>, "Niall Sweeny" <niall@...> wrote:
>
> >
> > They might be a little pricey, but the Emco miniature high voltage components would probably fit.
> >
> > From: Dan W. Dooley
> > Sent: Friday, October 04, 2013 5:00 PM
> > To: 'Tom Jobe' ; 'TekScopes'
> > Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > 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
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> >
> > ----- Original Message -----
> >
> > From: Dan W. Dooley
> >
> > To: 'Tom Jobe' ; TekScopes@... <mailto:TekScopes@...>
<mailto:TekScopes@... <mailto:TekScopes@...>>
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > From: Tom Jobe [mailto:tomjobe@...]
> > Sent: Friday, October 4, 2013 6:04 PM
> > To: TekScopes@... <mailto:TekScopes@...> <mailto:TekScopes@...
<mailto:TekScopes@...>>
> > Cc: dan@...
> > Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> > 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 -----
> >
> > From: wb5tka
> >
> > To: TekScopes@... <mailto:TekScopes@...> <mailto:TekScopes@...
<mailto:TekScopes@...>>
> >
> > 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@... <mailto:TekScopes@...> <mailto:TekScopes@...
<mailto: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,
> > > >
> > > >
> > >
> >
> >
> >
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2242 / Virus Database: 3222/6223 - Release Date: 10/04/13
> >
>
>
>
>




No virus found in this message.
Checked by AVG - www.avg.com <http://www.avg.com>
Version: 2014.0.4142 / Virus Database: 3604/6725 - Release Date: 10/05/13


Re: Understanding Voltage Multipliers

 

Also keep in mind that Tektronix was not always consistent in how they referred
to their high voltage multipliers.

The same 152-0493-00 multiplier is marked x14 in the 7844 schematic, x7 in the
7904 schematic, and x7 in the parts book.

On Sat, 05 Oct 2013 17:01:13 -0700, you wrote:

With all the current interest in voltage multipliers, including theory
and construction, I feel it is about time to talk technically about them.
I am inserting a schematic of a voltage tripler with an input square
wave of amplitude AB biased around 0 Volts. AB would be the
peak-to-peak voltage applied to the tripler.


Re: DIY High Voltage Multiplier Thoughts or Suggestions

 

Excellent. Thank you.

I probably have the same data in my old ECG book but I have no idea where I
stored it.

On 06 Oct 2013 06:22:52 -0700, you wrote:

Got the scanner working. Th file is in the Files section as ECG High Voltage Triplers.


Re: DIY High Voltage Multiplier Thoughts or Suggestions

mst3krules
 

Got the scanner working. Th file is in the Files section as ECG High Voltage Triplers.



---In TekScopes@..., <tekscopes@...> wrote:

I'm interested!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

mst3krules@... wrote:

>
>
> I found some data on the ECG high voltage triplers if you are still interested.
>
>
>
> ---In TekScopes@..., <tekscopes@...> wrote:
>
> Well, well, perhaps I've got it. Not finding any documentation on the ECG520 anywhere on line but knowing that it
> cross references to the ECG538 (which also seems to be lacking in documentation) and so on, I had to do some trial and
> error connecting. Connecting the "C" line, which I had assumed meant "common" or ground and that showing no success, I
> tried the other connections. "Low" and "Focus" and the three in combinations. With C connected by itself or in any
> other combination, there is no high voltage. With Low and Focus still connected (I had just disconnected the C
> connection) I got the -2.4 KV on the HV TP but also with a high pitched whine which is probably the HV oscillator
> running hard. Removing the Focus lead leaving only the connection to Low, the unit works. I measure -2.4 KV with no
> audible whine. My ears are good but I should not be able to hear 50 kHz :-)
>
> I briefly touched the end of the connector which is the HV out to the CRT with the end of the HV probe and it was
> obvious there was a very high voltage there with the "buzz" but I did not leave it there long enough to see just what
> the voltage is. I may have another look but I would presume somewhere between 7 and 8 KV. Does that sound right?
>
> Anyhow, now my next challenge will be to find a way to fit the new multiplier somewhere in the vicinity of the old
> one. I've got some ideas but will need to think about it a bit more.
>
> Thanks all for the help and suggestions. I'll do some more photo documenting when I get the device mounted.
>
>
>
> -- In TekScopes@... <mailto:TekScopes@...>, "Niall Sweeny" <niall@...> wrote:
>
> >
> > They might be a little pricey, but the Emco miniature high voltage components would probably fit.
> >
> > From: Dan W. Dooley
> > Sent: Friday, October 04, 2013 5:00 PM
> > To: 'Tom Jobe' ; 'TekScopes'
> > Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > 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
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> >
> > ----- Original Message -----
> >
> > From: Dan W. Dooley
> >
> > To: 'Tom Jobe' ; TekScopes@... <mailto:TekScopes@...>
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > From: Tom Jobe [mailto:tomjobe@...]
> > Sent: Friday, October 4, 2013 6:04 PM
> > To: TekScopes@... <mailto:TekScopes@...>
> > Cc: dan@...
> > Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> > 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 -----
> >
> > From: wb5tka
> >
> > To: TekScopes@... <mailto:TekScopes@...>
> >
> > 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@... <mailto: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,
> > > >
> > > >
> > >
> >
> >
> >
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2242 / Virus Database: 3222/6223 - Release Date: 10/04/13
> >
>
>
>
>


Re: DIY High Voltage Multiplier Thoughts or Suggestions

mst3krules
 

I just found out my scanner isn't working correctly. I will post it as soon as I can get it scanned.



---In TekScopes@..., <tekscopes@...> wrote:

I'm interested!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

mst3krules@... wrote:

>
>
> I found some data on the ECG high voltage triplers if you are still interested.
>
>
>
> ---In TekScopes@..., <tekscopes@...> wrote:
>
> Well, well, perhaps I've got it. Not finding any documentation on the ECG520 anywhere on line but knowing that it
> cross references to the ECG538 (which also seems to be lacking in documentation) and so on, I had to do some trial and
> error connecting. Connecting the "C" line, which I had assumed meant "common" or ground and that showing no success, I
> tried the other connections. "Low" and "Focus" and the three in combinations. With C connected by itself or in any
> other combination, there is no high voltage. With Low and Focus still connected (I had just disconnected the C
> connection) I got the -2.4 KV on the HV TP but also with a high pitched whine which is probably the HV oscillator
> running hard. Removing the Focus lead leaving only the connection to Low, the unit works. I measure -2.4 KV with no
> audible whine. My ears are good but I should not be able to hear 50 kHz :-)
>
> I briefly touched the end of the connector which is the HV out to the CRT with the end of the HV probe and it was
> obvious there was a very high voltage there with the "buzz" but I did not leave it there long enough to see just what
> the voltage is. I may have another look but I would presume somewhere between 7 and 8 KV. Does that sound right?
>
> Anyhow, now my next challenge will be to find a way to fit the new multiplier somewhere in the vicinity of the old
> one. I've got some ideas but will need to think about it a bit more.
>
> Thanks all for the help and suggestions. I'll do some more photo documenting when I get the device mounted.
>
>
>
> -- In TekScopes@... <mailto:TekScopes@...>, "Niall Sweeny" <niall@...> wrote:
>
> >
> > They might be a little pricey, but the Emco miniature high voltage components would probably fit.
> >
> > From: Dan W. Dooley
> > Sent: Friday, October 04, 2013 5:00 PM
> > To: 'Tom Jobe' ; 'TekScopes'
> > Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > 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
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> >
> > ----- Original Message -----
> >
> > From: Dan W. Dooley
> >
> > To: 'Tom Jobe' ; TekScopes@... <mailto:TekScopes@...>
> >
> > 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.
> >
> >
> >
> > Dan W. Dooley
> >
> > email: dan@...
> >
> > Dooley's Treasure Chest
> >
> >
> >
> > From: Tom Jobe [mailto:tomjobe@...]
> > Sent: Friday, October 4, 2013 6:04 PM
> > To: TekScopes@... <mailto:TekScopes@...>
> > Cc: dan@...
> > Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
> >
> >
> > Hi Dan,
> >
> > 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.
> >
> > tom jobe...
> >
> > 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 -----
> >
> > From: wb5tka
> >
> > To: TekScopes@... <mailto:TekScopes@...>
> >
> > 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@... <mailto: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,
> > > >
> > > >
> > >
> >
> >
> >
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2242 / Virus Database: 3222/6223 - Release Date: 10/04/13
> >
>
>
>
>


Re: Is this amount of noise typical? Tek 2465

 

 <<So I use that one for 'rough' work for now. Hope to get a 160Mhz Rigol 

Arb Function gen to use to cal, along with a jim williams pulse gen.>>


---In tekscopes@..., <mosaicmerc@...> wrote:

Change the caps on the Inverter board for sure.
I just did 3 of those scopes (all mine personally) & posted pics of the
caps . Of the 3 scopes, I got leaking caps on all 3 inverter boards.
The X2 caps are also usually swollen and crazed.
There's no batt on the 2465 so u can leave the A5 control board alone.
Might be a good idea to loosen the backplate of the chassis before
removing and installing the LVPS assy. Can be a bit tight.
Lube the fan motor if u can and be careful when pulling off /inserting
the 'waterwheel' fan blades. You have to pull the Wheel and tap the
centre at the same time to loosen the collet.
Do heatsink the U800, I did a thermal check and it makes about 50%
difference in Delta temps. PC video cards have good low profile Heatsinks.

Love these scopes....I used to gaze at them advertised in Radio
Electronics when I was in college, in the 80's...they cost as much as a
car in those days. Ebay allowed me to get 'em this year. Ended up with
one extra (c/w 500Mhz tek probes) due to winning a surprisingly low
bid....but it needs cal.
So I use that one for 'rough' work for now. Hope to get a 160Mhz Rigol
Arb Function gen to use to cal, along with a jim williams pulse gen.




Ancel

Out of curiousity what part of the calibration process would you need the Jim Williams pulse generator for?


Re: DIY 3X High Voltage Multiplier Installation

Michael A. Terrell
 

Tom Jobe wrote:

Hi Reed,
Thank you for documenting the ECG538/NTE538 multiplier adaptation for the 4xx scopes such as the 465 and 475 families!
Who would you suggest as a source for this multiplier? I would like to buy one for the last 465 parts scope that I stole the multiplier out of.
I'm leery of buying one from someone who just shows a picture of a transistor as being a NTE538 or a ECG538.
Here are the current stocking distributors, or you may be able to buy it direct from NTE:

http://dilp.netcomponents.com/cgi-bin/nteinc.asp?partnumber1=NTE538


Re: Understanding Voltage Multipliers

Don Black <donald_black@...>
 

Nice description. I would point out that it doesn't matter what the DC bias is on the input square wave provided it doesn't exceed C1 voltage rating. C1 blocks any DC and it's only the peak to peak voltage which matters. Not trying to pick nits but since you specified the input at DC it might confuse some trying to understand it.

Don Black.

On 06-Oct-13 11:01 AM, Reed Dickinson wrote:
With all the current interest in voltage multipliers, including theory and construction, I feel it is about time to talk technically about them.
I am inserting a schematic of a voltage tripler with an input square wave of amplitude AB biased around 0 Volts.  AB would be the peak-to-peak voltage applied to the tripler.



Lets assume the tripler is working properly and analyze what waveforms and voltages can be found at each of the circled node points 1 through 6.

Node 1.
C1 charges to the voltage B through D1 so we will see a square wave of amplitude AB with the lower portion of the square wave at zero volts.

Node 4.
C4 will charge to voltage level A through D2 plus the charge on C1 so we will see a DC level of AB volts at point 4.

Node 2.
C2 charges to voltage level B through D3 plus the DC charge on C1 so we will see a square wave of amplitude AB with the lower portion of the square wave at AB volts at point 2.

Node 5.
C5 charges to voltage level A through D4 plus the DC charge on C4 so we will see a DC voltage of 2AB at point 5.

Node 3.
C3 charges to voltage level B through D5 plus the bias of AB from C2 so we will see a square wave of amplitude AB with the lower portion of the square wave at 2AB volts at point 3.

Node 6.
C6 charges to voltage A through D6 plus the voltage of 2AB from C5 so we will see a DC voltage of 3AB at point 6.

As you can see, each section composed of two capacitors and two diodes adds the value AB to the DC level found on the bottom side of the nodes 4,5 and 6 on the drawing.
A rule of thumb: the number of sections is the multiplier value.  So, multiply the square wave AB peak-to-peak value by the number of sections to get the output high voltage.
Each capacitor must have a working voltage of at least 1.5AB and each diode should have a peak inverse voltage of 2AB.  I specify 2AB because diodes are more prone to failure than capacitors.

If you wanted to make a voltage 6X multiplier you would just add three more sections to the drawing above.  The input current is the required output current multiplier by the number of sections.
To construct a negative voltage multiplier reverse each diode.

Reed Dickinson


Re: DIY 3X High Voltage Multiplier Installation

Michael A. Terrell
 

Reed Dickinson wrote:

Hi Dan:

The ECH520 is perhaps an electrical equivalent of the ECG538 but is not amechanical equivalent. I am guessing as I cannot find any reference to a ECG520. I will give you the correct connections for a ECG538 which, I hope, will suffice for the ECG520 if the two are indeed electrical equivalents.

To use the ECG538 in a 4XX scope first remove the old 3X multiplier by removing the two nylon nuts and cutting the plastic threaded shafts off so the 3X can be removed. Position the new ECG538 such that the output cable is toward the front and drill two holes in the aluminum plate at the bottom of the shielded well. Mount the 538 using screws and hardware. Splice the old HV lead onto the new HV lead from the 538, measure the correct distance to cut twice and then cut once. Ground the D and IN leads on the 538 and connect the HV input from the scope to the LOW lead input on the 538. It may be necessary to trim metal off the cover that was over the original 3X multiplier. Do not discard the metal cover as it is a HV shield and should be in place.

Fire up and watch for a trace.

I have a 20+ year old ECG cross reference book somewhere. If I can find it, I will get the data. It seems to me that the 520 was for a B&W or 13" color TV, but I haven't replaced a tripler since the late '70s.


Understanding Voltage Multipliers

Reed Dickinson
 

With all the current interest in voltage multipliers, including theory and construction, I feel it is about time to talk technically about them.
I am inserting a schematic of a voltage tripler with an input square wave of amplitude AB biased around 0 Volts.  AB would be the peak-to-peak voltage applied to the tripler.



Lets assume the tripler is working properly and analyze what waveforms and voltages can be found at each of the circled node points 1 through 6.

Node 1.
C1 charges to the voltage B through D1 so we will see a square wave of amplitude AB with the lower portion of the square wave at zero volts.

Node 4.
C4 will charge to voltage level A through D2 plus the charge on C1 so we will see a DC level of AB volts at point 4.

Node 2.
C2 charges to voltage level B through D3 plus the DC charge on C1 so we will see a square wave of amplitude AB with the lower portion of the square wave at AB volts at point 2.

Node 5.
C5 charges to voltage level A through D4 plus the DC charge on C4 so we will see a DC voltage of 2AB at point 5.

Node 3.
C3 charges to voltage level B through D5 plus the bias of AB from C2 so we will see a square wave of amplitude AB with the lower portion of the square wave at 2AB volts at point 3.

Node 6.
C6 charges to voltage A through D6 plus the voltage of 2AB from C5 so we will see a DC voltage of 3AB at point 6.

As you can see, each section composed of two capacitors and two diodes adds the value AB to the DC level found on the bottom side of the nodes 4,5 and 6 on the drawing.
A rule of thumb: the number of sections is the multiplier value.  So, multiply the square wave AB peak-to-peak value by the number of sections to get the output high voltage.
Each capacitor must have a working voltage of at least 1.5AB and each diode should have a peak inverse voltage of 2AB.  I specify 2AB because diodes are more prone to failure than capacitors.

If you wanted to make a voltage 6X multiplier you would just add three more sections to the drawing above.  The input current is the required output current multiplier by the number of sections.
To construct a negative voltage multiplier reverse each diode.

Reed Dickinson


Re: DIY 3X High Voltage Multiplier Installation

Tom Jobe <tomjobe@...>
 

Hi Reed,
Thank you for documenting the ECG538/NTE538  multiplier adaptation for the 4xx scopes such as the 465 and 475 families!
Who would you suggest as a source for this multiplier? I would like to buy one for the last 465 parts scope that I stole the multiplier out of.
I'm leery of buying one from someone who just shows a picture of a transistor as being a NTE538 or a ECG538.
tom jobe...
 
 
 

----- Original Message -----
Sent: Saturday, October 05, 2013 11:59 AM
Subject: [TekScopes] DIY 3X High Voltage Multiplier Installation

 

Hi Dan:

The ECH520 is perhaps an electrical equivalent of the ECG538 but is not a mechanical equivalent.  I am guessing as I cannot find any reference to a ECG520.  I will give you the correct connections for a ECG538 which, I hope, will suffice for the ECG520 if the two are indeed electrical equivalents.

To use the ECG538 in a 4XX scope first remove the old 3X multiplier by removing the two nylon nuts and cutting the plastic threaded shafts off so the 3X can be removed.  Position the new ECG538 such that the output cable is toward the front and drill two holes in the aluminum plate at the bottom of the shielded well.  Mount the 538 using screws and hardware.  Splice the old HV lead onto the new HV lead from the 538, measure the correct distance to cut twice and then cut once.  Ground the D and IN leads  on the 538 and connect the HV input from the scope to the LOW lead input on the 538.   It may be necessary to trim metal off the cover that was over the original 3X multiplier.  Do not discard the metal cover as it is a HV shield and should be in place.

Fire up and watch for a trace.

Reed Dickinson


Lemo Part 802

 

Hi all,
 
Anyone know where I can get a Lemo male insert part number 802? It is a size 2B  with one coax and two signal pins. This is to make up a BNC cable for the CG5011 calibrator. I can find all the other parts for the FGG.2B.802. ...
 
 
Thanks,
Tom
 
 
 


Re: DIY High Voltage Multiplier Thoughts or Suggestions

Garey Barrell <k4oah@...>
 

I'm interested!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

mst3krules@... wrote:



I found some data on the ECG high voltage triplers if you are still interested.



---In TekScopes@..., <tekscopes@...> wrote:

Well, well, perhaps I've got it. Not finding any documentation on the ECG520 anywhere on line but knowing that it cross references to the ECG538 (which also seems to be lacking in documentation) and so on, I had to do some trial and error connecting. Connecting the "C" line, which I had assumed meant "common" or ground and that showing no success, I tried the other connections. "Low" and "Focus" and the three in combinations. With C connected by itself or in any other combination, there is no high voltage. With Low and Focus still connected (I had just disconnected the C connection) I got the -2.4 KV on the HV TP but also with a high pitched whine which is probably the HV oscillator running hard. Removing the Focus lead leaving only the connection to Low, the unit works. I measure -2.4 KV with no audible whine. My ears are good but I should not be able to hear 50 kHz :-)

I briefly touched the end of the connector which is the HV out to the CRT with the end of the HV probe and it was obvious there was a very high voltage there with the "buzz" but I did not leave it there long enough to see just what the voltage is. I may have another look but I would presume somewhere between 7 and 8 KV. Does that sound right?

Anyhow, now my next challenge will be to find a way to fit the new multiplier somewhere in the vicinity of the old one. I've got some ideas but will need to think about it a bit more.

Thanks all for the help and suggestions. I'll do some more photo documenting when I get the device mounted.



-- In TekScopes@... <mailto:TekScopes@...>, "Niall Sweeny" <niall@...> wrote:

>
> They might be a little pricey, but the Emco miniature high voltage components would probably fit.
>
> From: Dan W. Dooley
> Sent: Friday, October 04, 2013 5:00 PM
> To: 'Tom Jobe' ; 'TekScopes'
> Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
>
>
>
> 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.
>
>
>
> Dan W. Dooley
>
> email: dan@...
>
> Dooley's Treasure Chest
>
>
>
> 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
>
>
> Hi Dan,
>
> 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.
>
> tom jobe...
>
>
> ----- Original Message -----
>
> From: Dan W. Dooley
>
> To: 'Tom Jobe' ; TekScopes@... <mailto:TekScopes@...>
>
> 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.
>
>
>
> Dan W. Dooley
>
> email: dan@...
>
> Dooley's Treasure Chest
>
>
>
> From: Tom Jobe [mailto:tomjobe@...]
> Sent: Friday, October 4, 2013 6:04 PM
> To: TekScopes@... <mailto:TekScopes@...>
> Cc: dan@...
> Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
>
>
> Hi Dan,
>
> 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.
>
> tom jobe...
>
> 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 -----
>
> From: wb5tka
>
> To: TekScopes@... <mailto:TekScopes@...>
>
> 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@... <mailto: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,
> > >
> > >
> >
>
>
>
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2242 / Virus Database: 3222/6223 - Release Date: 10/04/13
>




Re: DIY High Voltage Multiplier Thoughts or Suggestions

Tom Jobe <tomjobe@...>
 


I don't know about anyone else, but I'm interested in your ECG multiplier information!
tom jobe...
 
 
 
 

----- Original Message -----
Sent: Saturday, October 05, 2013 1:34 PM
Subject: [TekScopes] RE: Re: DIY High Voltage Multiplier Thoughts or Suggestions

 

I found some data on the ECG high voltage triplers if you are still interested.



---In TekScopes@..., <tekscopes@...> wrote:

Well, well, perhaps I've got it. Not finding any documentation on the ECG520 anywhere on line but knowing that it cross references to the ECG538 (which also seems to be lacking in documentation) and so on, I had to do some trial and error connecting. Connecting the "C" line, which I had assumed meant "common" or ground and that showing no success, I tried the other connections. "Low" and "Focus" and the three in combinations. With C connected by itself or in any other combination, there is no high voltage. With Low and Focus still connected (I had just disconnected the C connection) I got the -2.4 KV on the HV TP but also with a high pitched whine which is probably the HV oscillator running hard. Removing the Focus lead leaving only the connection to Low, the unit works. I measure -2.4 KV with no audible whine. My ears are good but I should not be able to hear 50 kHz :-)

I briefly touched the end of the connector which is the HV out to the CRT with the end of the HV probe and it was obvious there was a very high voltage there with the "buzz" but I did not leave it there long enough to see just what the voltage is. I may have another look but I would presume somewhere between 7 and 8 KV. Does that sound right?

Anyhow, now my next challenge will be to find a way to fit the new multiplier somewhere in the vicinity of the old one. I've got some ideas but will need to think about it a bit more.

Thanks all for the help and suggestions. I'll do some more photo documenting when I get the device mounted.



-- In TekScopes@..., "Niall Sweeny"
>
> They might be a little pricey, but the Emco miniature high voltage components would probably fit.
>
> From: Dan W. Dooley
> Sent: Friday, October 04, 2013 5:00 PM
> To: 'Tom Jobe' ; 'TekScopes'
> Subject: RE: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
>
>
>
> 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.
>
>
>
> Dan W. Dooley
>
> email: dan@...
>
> Dooley's Treasure Chest
>
>
>
> 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
>
>
> Hi Dan,
>
> 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.
>
> tom jobe...
>
>
> ----- Original Message -----
>
> From: Dan W. Dooley
>
> To: 'Tom Jobe' ; TekScopes@...
>
> 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.
>
>
>
> Dan W. Dooley
>
> email: dan@...
>
> Dooley's Treasure Chest
>
>
>
> From: Tom Jobe [mailto:tomjobe@...]
> Sent: Friday, October 4, 2013 6:04 PM
> To: TekScopes@...
> Cc: dan@...
> Subject: Re: [TekScopes] Re: DIY High Voltage Multiplier Thoughts or Suggestions
>
>
> Hi Dan,
>
> 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.
>
> tom jobe...
>
> 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 -----
>
> From: wb5tka
>
> To: TekScopes@...
>
> 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 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,
> > >
> > >
> >
>
>
>
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2242 / Virus Database: 3222/6223 - Release Date: 10/04/13
>

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