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On Aug 24, 2019, at 9:38 PM, John Griessen <john@...> wrote:

On 8/24/19 8:23 PM, Greg Muir via Groups.Io wrote:

From a little more digging it appears that the measurement Tek uses applies to the diameter of the metal part of the probe tip body itself; sort of a mystery since Tek does not indicate what they are referring to in any of their literature.

It's a planned obsolescence thing. Mentioning that the tip male prong and barrel on the body of the probe are well known standards might reduce sales. Most companies in test equipment know that they make plenty from
selling accessories.

5mm barrel and 2.5mm barrel on probe tips are a pseudo standard with Tek and it allows any low frequency parts
to swap out or substitute willy nilly.

I like some thin small probes by HP such as 10017A probes. Their probe tip barrel diameter is 2.33mm, not standard with Tek at all, and not even a perfect input capacitance match, but I use them up to 20 MHz with no big troubles.

For higher frequencies, the probe for the scope will be better.

An example of how 5mm probe tip barrel diameters allow swapping things is those funny elephant trunk-looking
tips for the P6046 diff probes, and also the nifty shorting tips that come with those probes for performance checks and cal.

I wonder if the same company could make a batch of HV transformers for the 453 scope? I think several users of this group, including myself, have 453 scopes with bad HV transformers.
Thanks,
Harry

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of drawding@...
Sent: Sunday, August 25, 2019 1:25 AM
To: [email protected]
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

"Where do they get the cores to make a compatible transformer that works in the 576 circuit. This is not a 115v 60 Hz transformer."

I believe that they make them in house. I sent them the original Tek transformer specification. I got the specification drawing from Bob Koller (now posted online as per this thread).

Thanks,
Dave

The plug has finally broken off the captive lead on my 7CT1N, the one that goes out to a vertical amp or time-base depending on which side you have it installed. I'm sure I'm not the first victim of this. I can obviously replace it with an ordinary BNC plug, and am doing so temporarily (I hope), but it rattles around etc., and it also has a redundant earth connection. I'm wondering if there is something more suitable, short of the unobtainium (I presume) entire 195-0095-00 assembly, that is maybe made of plastic and/or only has the inner connecting ring.

Thanks in advance

EJP

The plug has finally broken off the captive lead on my 7CT1N, the one that
goes out to a vertical amp or time-base depending on which side you have it
installed. I'm sure I'm not the first victim of this. I can obviously
replace it with an ordinary BNC plug, and am doing so temporarily (I hope),
but it rattles around etc., and it also has a redundant earth connection.
I'm wondering if there is something more suitable, short of the unobtainium
(I presume) entire 195-0095-00 assembly, that is maybe made of plastic
and/or only has the inner connecting ring.

Thanks in advance

EJP

I have two 576, if you told me which test you need to compare, I will do
it with mine. Do you know ferrite core specs? Could be changed some
transformer HV turns for a voltage multiplier?



FERRITE CORE E 20 N27
Core Type : E
Core Size : E20/10/6
Core Material Grade : N27
For Use With : -
Effective Magnetic Path Length : 46.3mm
Ae Effective Cross Section Area : 32.1mm?
Inductance Factor Al : 1.3?H
Product Range : B66311 Series
SVHC : No SVHC (15-Jun-2015)
Accessory Type : Ferrite Core
Material Grade : N27
-----Mensaje original-----
De: [email protected] [mailto:[email protected]] En nombre de peter
bunge
Enviado el: sábado, 24 de agosto de 2019 16:08
Para: [email protected]
Asunto: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Thanks David for your generous offer;
Where do they get the cores to make a compatible transformer that works in
the 576 circuit. This is not a 115v 60 Hz transformer.
A friend suggested a plate transformer and doublers or triplers. 225v is
also needed.
I have been looking at using a 4 kV and 225 V switching power supplies
from China and I have used some for other projects. They tend to be noisy
but can be cleaned up.
Since my 576 is still working there is no great urgency.
I also want to look at my friend's 577 and compare it to my 576. His is
smaller and lighter but may not do as much.
My 576 does weird things at lower currents (all loops) and PNP do not seem
to work the same as NPN (lack of steps) so the transformer is not the only
issue. I spent a couple of days working on it a few years ago but could not
improve it.
I need to find someone with a 576 and compare traces to see if mine is
"normal".
I need the 1500v capability which rules out some of the newer ones which
are also more expensive.
I will think about your offer.
Peter

On Fri, Aug 23, 2019 at 4:28 PM drawding@... <drawding@...

wrote:

Yes. David Rawding is still here.

: )

I bought five professionally made transformers. One was donated to
Bob for his kind help. Two were used by me. Two were sold. I am all

out.

Another run is ~ $1k for 5 more. Five is the minimum order. A bit
pricey, I know. However, they are made by a professional transformer
company. Fully enclosed and potted in silicone. If you consider what
technical wages are today and overhead and materials, I would say it
is fair pricing. However, at the hobby level, it is pricey.

If we can find five buyers (though this seems unlikely), I will
handle the details, and will sell at my cost + shipping.

Also, as you can see from this thread several people have been
successful winding their own.

One gentleman came here a year or so ago, asked a bunch of questions,
got great support from the group, ended up successfully winding his
own, and left. He was asked to put some details together (pictures,
documentation, video, etc), but apparently could not be bothered.

I hope you find a solution.

Thanks,
Dave