|
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,
|
Checking the schematic shows that the high voltage multiplier is accepting a 4900 volt peak-to-peak input to generate between 14 and 16
kilovolts so it should be a x3 multiplier.
The 465 parts list I checked shows Tektronix part number 152-0552-00 on the left side and 152-0442-00 on the right side for U1432. The part
number on the right side is for a schottky diode so that is a misprint. The Book says 152-0552-00 is a x3 high voltage multiplier with an
input voltage of 5 kilovolts and an output voltage of 15 kilovolts which is consistent with my analysis above.
Here is a schematic of what you will find inside:
I think several people who participate in the list have successfully built replacement high voltage multipliers.
Most of the diodes and capacitors will need to withstand at least twice the peak-to-peak input voltage so I would consider 15 kilovolts the
minimum voltage rating. The diodes need to be fast recovery types because the input frequency is high. Soldered connections need to be
smooth to prevent dielectric breakdown.
At these high voltages, the circuit will need to be enclosed with a conformal coating or potted to prevent corona discharge. Multiple
coatings of Q-Dope which is polystyrene dissolved in solvents should work for this. Ideally a vacuum chamber is used to remove all air and
air bubbles.
Going by the specifications of U1432, I believe it also includes a high voltage 510 kOhm series resistor built into the output.
Someone else on the list may have a suggestion for a viable replacement. x3 high voltage multipliers were used for many different CRTs.
toggle quoted message
Show quoted text
On Tue, 24 Sep 2013 22:06:52 -0000, you 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,
|
Search the archives. Someone recently found a nice cheap source for these.
?
Also, in the photos area, there was an x-ray of a multiplier.
?
You can also use wax to pot it.
?
Tom
?
?
?
toggle quoted message
Show quoted text
----- Original Message -----
Sent: Tuesday, September 24, 2013 7:10
PM
Subject: Re: [TekScopes] DIY High Voltage
Multiplier Thoughts or Suggestions
?
Checking the schematic shows that the high voltage multiplier is accepting
a 4900 volt peak-to-peak input to generate between 14 and 16
kilovolts so
it should be a x3 multiplier.
The 465 parts list I checked shows
Tektronix part number 152-0552-00 on the left side and 152-0442-00 on the
right side for U1432. The part
number on the right side is for a schottky
diode so that is a misprint. The Book says 152-0552-00 is a x3 high voltage
multiplier with an
input voltage of 5 kilovolts and an output voltage of 15
kilovolts which is consistent with my analysis above.
Here is a
schematic of what you will find
inside:
http://www.electronics-tutorials.ws/articles/volt2.gif
I
think several people who participate in the list have successfully built
replacement high voltage multipliers.
Most of the diodes and capacitors
will need to withstand at least twice the peak-to-peak input voltage so I
would consider 15 kilovolts the
minimum voltage rating. The diodes need to
be fast recovery types because the input frequency is high. Soldered
connections need to be
smooth to prevent dielectric breakdown.
At
these high voltages, the circuit will need to be enclosed with a conformal
coating or potted to prevent corona discharge. Multiple
coatings of Q-Dope
which is polystyrene dissolved in solvents should work for this. Ideally a
vacuum chamber is used to remove all air and
air bubbles.
Going by
the specifications of U1432, I believe it also includes a high voltage 510
kOhm series resistor built into the output.
Someone else on the list
may have a suggestion for a viable replacement. x3 high voltage multipliers
were used for many different CRTs.
On Tue, 24 Sep 2013 22:06:52 -0000,
you 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,
|
If anyone has experience de-potting a HV Multiplier I would like to hear how
to do it. I would be willing to try de-potting a dead one I have as an
experiment to see how hard it is and if the resulting circuit can be
repaired.
I understand that the vendor that made the 7000 multipliers for by Tek may
have used different potting materials over the years and that some materials
are easier to de-pot than others. So advice on how to determine which
materials were used would be appreciated as well.
Dennis
toggle quoted message
Show quoted text
-----Original Message-----
From: wb5tka, Sent: Tuesday, September 24, 2013 3:07 PM
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,
|
As I remember, there is a nice store bought NTE multiplier
that?can be adapted to?the 4xx scopes such as the 465.
The Tekscopes message archive has the information, if it is
all still available.
Having the HV multiplier die in a 4xx scope is a common
problem in my experience.
tom jobe...
?
?
?
toggle quoted message
Show quoted text
----- Original Message -----
Sent: Tuesday, September 24, 2013 3:06
PM
Subject: [TekScopes] DIY High Voltage
Multiplier Thoughts or Suggestions
?
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,
|
This may take you to some good info. Though it's hard to tell now days with
yahooo
?
?
?
?
toggle quoted message
Show quoted text
----- Original Message -----
Sent: Tuesday, September 24, 2013 8:24
PM
Subject: RE: [TekScopes] DIY High Voltage
Multiplier Thoughts or Suggestions
?
If anyone has experience de-potting a HV Multiplier I would like to hear
how
to do it. I would be willing to try de-potting a dead one I have as
an
experiment to see how hard it is and if the resulting circuit can
be
repaired.
I understand that the vendor that made the 7000
multipliers for by Tek may
have used different potting materials over the
years and that some materials
are easier to de-pot than others. So advice
on how to determine which
materials were used would be appreciated as
well.
Dennis
-----Original Message-----
From: wb5tka, Sent:
Tuesday, September 24, 2013 3:07 PM
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,
|
Depotting is a hard and hazardeos process. I talked with
manufacturer of a depotting machine and watched demonstration. Hot
(80 degree C) nitric and sulfuric acids are used. The machine is a
microprocessor controlled contraption? which contains a detachable
cassette with vessels for fresh and used chemicals, so it can be
detached and exchanged for new one. Disposing of used chemicals is a
problem since they are quite aggressive, so cassette is a workable
solution. I doubt that you can do that as a home brew, unless you
have access to a well equiped chemical lab. I was told that a sniff
of vapor of those heated acids? is deadly. Machine that I have seen
was intented for IC failure analasys labs, so it's working chamber
was relatively small, but it could possible accept voltage
multiplier.
Many years ago, something like 30 years, I tried mechanical
depotting of a solid state relay. I used Dremel with abrasive disk.
That was hard work and an abysmal failure. I would recommend
contracting out that job to a competent and appropriately equipped
lab.
Best of luck,
Miroslav Pokorni
On 9/24/2013 5:38 PM, Tom Miller wrote:
toggle quoted message
Show quoted text
?
This may take you to some good info. Though it's hard
to tell now days with yahooo
?
?
?
?
----- Original Message
-----
Sent: Tuesday,
September 24, 2013 8:24 PM
Subject: RE:
[TekScopes] DIY High Voltage Multiplier Thoughts or
Suggestions
?
If anyone has experience de-potting a HV Multiplier I
would like to hear how
to do it. I would be willing to try de-potting a dead
one I have as an
experiment to see how hard it is and if the resulting
circuit can be
repaired.
I understand that the vendor that made the 7000
multipliers for by Tek may
have used different potting materials over the years
and that some materials
are easier to de-pot than others. So advice on how to
determine which
materials were used would be appreciated as well.
Dennis
-----Original Message-----
From: wb5tka, Sent: Tuesday, September 24, 2013 3:07
PM
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,
|
I once depotted the HV multiplier assembly on a night vision tube. The intent was to make a diagram and understand its operation and not to repair (the tube itself was defective). I was lucky in that hot acetone swelled and softened the potting compound. Thus, I would let the assembly sit in the sealed hot liquid container then every day remove it and VERY gently pick off the loose bits of potting. This took two weeks but I was able to remove virtually all the potting compound. Quite a little multiplier assembly! However, even with the utmost care under a stereo microscope, I caused damage to the ultra fine transformer windings. I would say that repair of such a unit would be, at best, a long shot. I did get the diagram though.
Where I work we have ICs depotted for analysis. We have an outside lab do it because there is more to just removing some epoxy, it has to be done such that the connecting bond wires remain intact and the IC remain functional (at least as much as it was...). This takes a lot of skill.
Peter
toggle quoted message
Show quoted text
On 9/24/2013 10:02 PM, Miroslav Pokorni wrote:
Depotting is a hard and hazardeos process. I talked with manufacturer of a depotting machine and watched demonstration. Hot (80 degree C) nitric and sulfuric acids are used. The machine is a microprocessor controlled contraption which contains a detachable cassette with vessels for fresh and used chemicals, so it can be detached and exchanged for new one. Disposing of used chemicals is a problem since they are quite aggressive, so cassette is a workable solution. I doubt that you can do that as a home brew, unless you have access to a well equiped chemical lab. I was told that a sniff of vapor of those heated acids is deadly. Machine that I have seen was intented for IC failure analasys labs, so it's working chamber was relatively small, but it could possible accept voltage multiplier.
Many years ago, something like 30 years, I tried mechanical depotting of a solid state relay. I used Dremel with abrasive disk. That was hard work and an abysmal failure. I would recommend contracting out that job to a competent and appropriately equipped lab.
Best of luck,
Miroslav Pokorni
On 9/24/2013 5:38 PM, Tom Miller wrote:
This may take you to some good info. Though it's hard to tell now days with yahooo
----- Original Message -----
*From:* Dennis Tillman <mailto:dennis@...>
*To:* TekScopes@... <mailto:TekScopes@...>
*Sent:* Tuesday, September 24, 2013 8:24 PM
*Subject:* RE: [TekScopes] DIY High Voltage Multiplier Thoughts or
Suggestions
If anyone has experience de-potting a HV Multiplier I would like to hear how
to do it. I would be willing to try de-potting a dead one I have as an
experiment to see how hard it is and if the resulting circuit can be
repaired.
I understand that the vendor that made the 7000 multipliers for by Tek may
have used different potting materials over the years and that some materials
are easier to de-pot than others. So advice on how to determine which
materials were used would be appreciated as well.
Dennis
-----Original Message-----
From: wb5tka, Sent: Tuesday, September 24, 2013 3:07 PM
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,
|
I am seeing some references to the NTE multiplier within the thread but the scope referred to is the 475. The implication is that the 475 and 465 use the same multiplier. Or perhaps I misunderstood. The NTE replacement for the 152-0552-00 (which mine in my 465 is labeled as) is different from the NTE replacement suggested. That is the NTE538. That device has different connections. The 152-0552-00 has an input lead, ground lead and output. The suggested NTE has input, D, Lo, Focus and output. For use in the 4xx scopes, are the D and Lo leads simply connected together and grounded and the Focus ignored?
Dan,
toggle quoted message
Show quoted text
--- In TekScopes@..., "Tom Jobe" <tomjobe@...> wrote:
As I remember, there is a nice store bought NTE multiplier that can be adapted to the 4xx scopes such as the 465.
The Tekscopes message archive has the information, if it is all still available.
Having the HV multiplier die in a 4xx scope is a common problem in my experience.
tom jobe...
----- Original Message -----
From: wb5tka
To: TekScopes@...
Sent: Tuesday, September 24, 2013 3:06 PM
Subject: [TekScopes] DIY High Voltage Multiplier Thoughts or Suggestions
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,
|
The 475 parts list shows that it uses Tektronix part number 152-0552-00 which is the same voltage multiplier.
I think the focus lead is just a tap on the multiplier chain and/or resistor divider so it should be left insulated and unconnected.
I did not make any NTE multiplier recommendations because I could not find anybody that had them in stock or any data sheets. If I were
hunting for a voltage multiplier, I would either find an inexpensive parts donor or build one from discrete parts.
I have not seen a cross reference to which oscilloscopes use which voltage multipliers.
toggle quoted message
Show quoted text
On Wed, 25 Sep 2013 02:45:18 -0000, you wrote: I am seeing some references to the NTE multiplier within the thread but the scope referred to is the 475. The implication is that the 475 and 465 use the same multiplier. Or perhaps I misunderstood. The NTE replacement for the 152-0552-00 (which mine in my 465 is labeled as) is different from the NTE replacement suggested. That is the NTE538. That device has different connections. The 152-0552-00 has an input lead, ground lead and output. The suggested NTE has input, D, Lo, Focus and output. For use in the 4xx scopes, are the D and Lo leads simply connected together and grounded and the Focus ignored?
Dan,
|
This is really about de-potting not multipliers.
In another life, my professional one, I had quit a bit to do with de-potting
both outsourced and DIY. We made a lot of potted modules back in the 70s.
The outsource guys were amazing, the stuff came back like it was never
potted but it was pricey.
For DIY we used various products made by Dynaloy in 46226. Unfortunately my
favorite product Uresolve F is no longer available so you are on your own
for a recommendation. The stuff is very volatile so put it in a tight jar
and shake it a bit now and then to speed things up. Picking at it to expose
unattacked epoxy is very helpful.
A couple of other notes: 300 C turns most epoxies to dust in short order so
if you just want to trace out the circuitry and not save stuff it is a short
trip to the toaster oven. Most RTV does not like exposure to hydrocarbons.
They break the bond to embedded components and the RTV swells and gets quite
soft. When it starts to swell start picking at it to remove big hunks. This
is also helpful to prevent the swelling RTV from damaging the circuitry. If
it is in a plastic potting shell the swelling can break the shell if you
don't remove some of the swollen RTV. Gasoline works good as does Stoddard
solvent (old fashioned paint thinner)if you are cautious or an apartment
dweller.
Eric
toggle quoted message
Show quoted text
-----Original Message----- From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Peter Gottlieb Sent: Tuesday, September 24, 2013 7:23 PM To: TekScopes@... Subject: Re: [TekScopes] DIY High Voltage Multiplier Thoughts or Suggestions I once depotted the HV multiplier assembly on a night vision tube. The intent was to make a diagram and understand its operation and not to repair (the tube itself was defective). I was lucky in that hot acetone swelled and softened the potting compound. Thus, I would let the assembly sit in the sealed hot liquid container then every day remove it and VERY gently pick off the loose bits of potting. This took two weeks but I was able to remove virtually all the potting compound. Quite a little multiplier assembly! However, even with the utmost care under a stereo microscope, I caused damage to the ultra fine transformer windings. I would say that repair of such a unit would be, at best, a long shot. I did get the diagram though. Where I work we have ICs depotted for analysis. We have an outside lab do it because there is more to just removing some epoxy, it has to be done such that the connecting bond wires remain intact and the IC remain functional (at least as much as it was...). This takes a lot of skill. Peter On 9/24/2013 10:02 PM, Miroslav Pokorni wrote:
Depotting is a hard and hazardeos process. I talked with manufacturer of a
depotting machine and watched demonstration. Hot (80 degree C) nitric and
sulfuric acids are used. The machine is a microprocessor controlled
contraption which contains a detachable cassette with vessels for fresh and used chemicals, so it can be detached and exchanged for new one. Disposing of used chemicals is a problem since they are quite aggressive, so cassette is a workable solution. I doubt that you can do that as a home brew, unless you have access to a well equiped chemical lab. I was told that a sniff of vapor of those heated acids is deadly. Machine that I have seen was intented for IC failure analasys labs, so it's working chamber was relatively small, but it could possible accept voltage multiplier.
Many years ago, something like 30 years, I tried mechanical depotting of a solid state relay. I used Dremel with abrasive disk. That was hard work and an abysmal failure. I would recommend contracting out that job to a competent and appropriately equipped lab.
Best of luck,
Miroslav Pokorni
On 9/24/2013 5:38 PM, Tom Miller wrote:
This may take you to some good info. Though it's hard to tell now days
with yahooo
----- Original Message -----
*From:* Dennis Tillman <mailto:dennis@...>
*To:* TekScopes@... <mailto:TekScopes@...>
*Sent:* Tuesday, September 24, 2013 8:24 PM
*Subject:* RE: [TekScopes] DIY High Voltage Multiplier Thoughts or
Suggestions
If anyone has experience de-potting a HV Multiplier I would like to
hear how to do it. I would be willing to try de-potting a dead one I have as
an experiment to see how hard it is and if the resulting circuit can be
repaired.
I understand that the vendor that made the 7000 multipliers for by
Tek may have used different potting materials over the years and that some
materials are easier to de-pot than others. So advice on how to determine which
materials were used would be appreciated as well.
Dennis
-----Original Message-----
From: wb5tka, Sent: Tuesday, September 24, 2013 3:07 PM
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,
------------------------------------ Yahoo! Groups Links
|
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:
toggle quoted message
Show quoted text
?
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,
|
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.
Make sure any HV solder joints are smooth, and rounded, not just watch for wire whiskers. Otherwise, you will hve some corona.discharge, even if you don't see it. This was a common problem in the HV in CRT based monitors & TV sets. It caused the insulation to break down, and become a gooey mess.
|
When I disconnected the plug which connects the output of the HV multiplier to the CRT the problem is the same. No high voltage. About -500 volts on the HV TP. Same as the original problem I posted about. With the ground lead jumper which is on top of the board is lifted which isolates the multiplier, the HV oscillator seems to work. The voltage on the HV TP is now -2.4 KV. That would tend to point to the multiplier module as being the defective item within the circuit.
There is also a somewhat high pitched whine sound coming from somewhere in that area of the scope. I cannot isolate exactly where it comes from but it may be the HV transformer. The sound resembles the buzz of a mosquito. Louder of course. I never heard that sound when the scope was in operation prior to this failure.
There have also been some comments on this thread related to the CRT heater which leads to another question. As far as I can tell, the CRT heater is ok. At least from the standpoint of the heater not being open. I can measure continuity between pins 1 and 14. Approximately 15 to 20 ohms. This is with the socket to the CRT unplugged. I can also read continuity across that winding of the transformer. What I am now concerned about is that during the period of time when I had the oscillator running (the multiplier disconnected) and I am measuring high voltage I cannot see any glow from inside the rear neck of the CRT. Yes, I have the covers off of that area. Can it be that it is still not producing proper heater voltage as a result of the multiplier not being in circuit (that doesn't seem reasonable) or is it just not possible to actually see the heater glow from the rear of the CRT neck?
Dan,
toggle quoted message
Show quoted text
--- In TekScopes@..., "wb5tka" <dan@...> 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,
|
If the CRT has air in it it will get unusually hot unusually fast..but
will Not glow, as the air is conducting the heat away and will not allow
it to get to incandescent temperature..as in a cracked CRT ..:(
And ..HV applied to a cracked tube usually results in an arc .. which
often makes a whizzing/hissing noise,kinda hollow sounding..
but I hope this isn't your problem..!!? .. ?? Dana? d:)>
|
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
toggle quoted message
Show quoted text
--- 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,
|
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.
?
?
toggle quoted message
Show quoted text
----- 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
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,
>
>
> >
>
|
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. ? ?
toggle quoted message
Show quoted text
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? 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,
> >
> >
>
|
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...
?
toggle quoted message
Show quoted text
----- 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.
?
?
Dan
W. Dooley
? email: dan@...
?
?
?
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
?
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,
> >
> >
>
|
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. ? ?
toggle quoted message
Show quoted text
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,
> >
> >
>
|
David Hess
Eric Schumacher
Michael A. Terrell