开云体育

On Aug 25, 2019, at 3:16 PM, Dave Seiter <d.seiter@...> wrote:

Gaffer tape (or Gaff tape) is used in studios, sets and theaters for EVERYTHING. It's like duct tape, but holds better, tears better, feels better, etc, and tends not to leave a mess behind if you leave on too long. It can also be really pricey.
-Dave


On Sunday, August 25, 2019, 05:45:02 AM PDT, Lawrance A. Schneider <llaassllaaass@...> wrote:

Hi,

I’d never heard of ‘gaffer tape”. Why not just plane plastic electrical tape?


Larry

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@...> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

EJP

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@...> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

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

And 547s and 7934s ...

DaveD


On 8/25/2019 8:12 AM, RustySparks wrote:

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

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

Hello All,

I have a 585A scope that has me stumped.. the LV voltages are out of spec and I cannot find the problem. Here are the voltage readings;

-150 = -182
-100 = -115
225 = 263
350 = 409
500 = 587

The -150v adjustment pot does not change the voltage value at all. All the tubes were pulled and tested for shorts and emission. Not being very good at diagnosis I shotgunned all the electrolytics and filter caps although most of the tested good in circuit I found a couple of bad ones. No improvement. I have the schematic and can upload that if it helps. Can anyone suggest a way I can isolate the circuit causing me grief? The scope is clean and intact otherwise.

Thanks in advance.

And 547s and 7934s ...

DaveD


On 8/25/2019 8:12 AM, RustySparks wrote:

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

On Aug 25, 2019, at 5:37 AM, EJP <esmond.pitt@...> wrote:

When I went to put on a standard soldered BNC plug I found there is no shielding in the cable, only a pretty thick set of strands for the inner conductor, so I was unable to even fix the outer cover on. So I settled for just the pin. I'm not happy with it, as it is uninsulated: gaffer tape awaits, but also a better solution, if there is one.

EJP