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Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

A few things I can supply to encourage you to find your
"quiet virtues" as described by Dave, are:

1) use double stick cellophane tape for your inter-winding
insulation. The Scotch archival sort meant for sticking
photographs into an album is ideal. The electrical
insulation needs are minimal, and the tape will hold the
next layer firmly in place, preventing unwinding if you
relax the wire tension.

2) You can easily break up this job into a bunch of 5 minute
segments. Keep a tablet of paper next to your simple winder
to keep track of what turn you are on, and other details.

3) make your taps by dragging a loop of wire off to the
desired side, and twist it into a becoming the termination
lead. I use a pointed hook with a handle to make the
twisting easy.
4) use one of the tnermaleze types of wire. That way all you
need to do to tin the wire is put a blob of solder on your
soldering iron tip, and run it over the twisted up wire.
5) remember that solder dissolves copper and incorporates it
in the alloy. Keep your soldering time on these fine wires
short.

You can make a simple winder by cutting out two pieces of
soft pine, or plywood into rectangles about 1.5x 3 inches in
size.

Drill through both pieces simultaneously near the top with
a 1/8 inch bit, and hot glue the two rectangles spaced about
an inch apart onto another board, with the drill bit in
the holes to maintain alignment.

When the glue is set, remove the drill bit, and replace it
with a bent up piece of wire that has been formed into a small
crank. Coat hanger wire will do nicely.

Insert the wire into the two holes. You might want to put a
couple of nuts, beads, or a standoff between the handle and
the board to keep the wire handle from rubbing...

On the end of the wire that sticks out past the two rectangular
pieces of wood, carefully wind up adhesive tape to make a
mandrel to support your coil former. Use a couple three toothpicks
as wedges to keep the former on the "mandrel", and you are
ready to wind.

-Chuck Harris


On Fri, 16 Feb 2024 16:54:04 -0800 "Conrad Hoffman"
<choffman@...> wrote:
Thanks! I'll see how much history I can find. Not sure about my
patience and other virtues, but I do have an excess of dogged
perseverance once I get started on something. ?
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

On Wed, Feb 14, 2024 at 08:38 AM, Jean L. RUELLE wrote:
pure Bonheur
Pre happiness

larry

I now now more French!
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Thanks! I'll see how much history I can find. Not sure about my patience and other virtues, but I do have an excess of dogged perseverance once I get started on something. ?
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

¿ªÔÆÌåÓý

I used the flyback layer method to rewind my 453 in 2015.? No wax.? Still working.? I documented it in the TekScopes group, see topic and photo album "453 HV Transformer Rewind".? While it requires only a low-tech winder, the quiet virtues are essential: calm, patience, fortitude, and a steady hand.? I would do it again but I also happily paid Chuck for a 547 transformer.

Dave Wise

Bifilar winding gives you the correct grid-cathode?capacitance to match the RC time constants Tek used.

From: [email protected] <[email protected]> on behalf of Chuck Harris <cfharris@...>
Sent: Thursday, February 15, 2024 8:47 PM
To: [email protected] <[email protected]>
Subject: Re: [TekScopes2] New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice
?
When I did the original winding, I told all on this group.? You might
try looking for my original postings.

The transformer is really best wound using a "universal" wind, which
is a self supporting style of winding that keeps the potential between
every wire that comes near to other wires fairly low.? This also keeps
the capacitance coupling between the windings low allowing for a higher
Q.

A factor that confuses many is that all windings are bifilar, tapped
when necessary, except the last several hundred turns.? One of the
bifilar wires is used to feed the cathode circuits, and the other feeds
the grid circuits.? That makes the difference in voltage between the
two wires in the bifilar pair only about 70V.? If you segregate the
various winding sections into layers of their own, you end up with
very high voltages between the sections, and could have a flash over.

However, you can wind bifilar, in layers, using the "flyback" method,
where every layer of wire gets covered with a layer of tape, then
flys back over the wires in the layer to the starting side, and
gets another layer of tape before the next layer begins.? This keeps
the layers isolated so the couple hundred volts they generate, at
1.6V/T won't arc over the winding.

Vacuum potting in beeswax after you are all done is helpful, but not
100% necessary with the "flyback" technique.

-Chuck Harris


On Thu, 15 Feb 2024 13:33:15 -0800 "Conrad Hoffman"
<choffman@...> wrote:
> Sorry about the chat thing. I wanted to send a PM but couldn't figure
> out how to do it; hey, I'm getting old! Anyway, great to read about
> your adventures and I fully understand that we have priorities, not
> to mention the physical abilities to get things done. Now, I have a
> lot of enameled wire, a homebrew winder (just a drill chuck, crank
> and turns counter) and, I think, even the Tek transformer drawing.
> I've wound transformers for switching supplies and other stuff, but
> the physical details of the Tek transformer are a bit beyond me. I'd
> give winding one a try, but I don't want to wind it ten times to get
> it right! Would you be willing to share any helpful hints if I wanted
> to give it a go? I love my 545B (both of them) but in all honesty I'm
> wondering if it's time to dump them and get a cheap Siglent digital
> to pair with my 7000 mainframe. Of course I couldn't bear to scrap
> them, I can no longer lift them and finding anybody local that would
> actually use them, as opposed to just grabbing the tubes, is probably
> a pipe dream.
>
>
>
>
>






Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

When I did the original winding, I told all on this group. You might
try looking for my original postings.

The transformer is really best wound using a "universal" wind, which
is a self supporting style of winding that keeps the potential between
every wire that comes near to other wires fairly low. This also keeps
the capacitance coupling between the windings low allowing for a higher
Q.

A factor that confuses many is that all windings are bifilar, tapped
when necessary, except the last several hundred turns. One of the
bifilar wires is used to feed the cathode circuits, and the other feeds
the grid circuits. That makes the difference in voltage between the
two wires in the bifilar pair only about 70V. If you segregate the
various winding sections into layers of their own, you end up with
very high voltages between the sections, and could have a flash over.

However, you can wind bifilar, in layers, using the "flyback" method,
where every layer of wire gets covered with a layer of tape, then
flys back over the wires in the layer to the starting side, and
gets another layer of tape before the next layer begins. This keeps
the layers isolated so the couple hundred volts they generate, at
1.6V/T won't arc over the winding.

Vacuum potting in beeswax after you are all done is helpful, but not
100% necessary with the "flyback" technique.

-Chuck Harris


On Thu, 15 Feb 2024 13:33:15 -0800 "Conrad Hoffman"
<choffman@...> wrote:
Sorry about the chat thing. I wanted to send a PM but couldn't figure
out how to do it; hey, I'm getting old! Anyway, great to read about
your adventures and I fully understand that we have priorities, not
to mention the physical abilities to get things done. Now, I have a
lot of enameled wire, a homebrew winder (just a drill chuck, crank
and turns counter) and, I think, even the Tek transformer drawing.
I've wound transformers for switching supplies and other stuff, but
the physical details of the Tek transformer are a bit beyond me. I'd
give winding one a try, but I don't want to wind it ten times to get
it right! Would you be willing to share any helpful hints if I wanted
to give it a go? I love my 545B (both of them) but in all honesty I'm
wondering if it's time to dump them and get a cheap Siglent digital
to pair with my 7000 mainframe. Of course I couldn't bear to scrap
them, I can no longer lift them and finding anybody local that would
actually use them, as opposed to just grabbing the tubes, is probably
a pipe dream.
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Sorry about the chat thing. I wanted to send a PM but couldn't figure out how to do it; hey, I'm getting old! Anyway, great to read about your adventures and I fully understand that we have priorities, not to mention the physical abilities to get things done. Now, I have a lot of enameled wire, a homebrew winder (just a drill chuck, crank and turns counter) and, I think, even the Tek transformer drawing. I've wound transformers for switching supplies and other stuff, but the physical details of the Tek transformer are a bit beyond me. I'd give winding one a try, but I don't want to wind it ten times to get it right! Would you be willing to share any helpful hints if I wanted to give it a go? I love my 545B (both of them) but in all honesty I'm wondering if it's time to dump them and get a cheap Siglent digital to pair with my 7000 mainframe. Of course I couldn't bear to scrap them, I can no longer lift them and finding anybody local that would actually use them, as opposed to just grabbing the tubes, is probably a pipe dream.
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Hi Chuck

?

For me it was pure Bonheur ( what is the English name for ?) to read your message.

?

If I go thru my present problem with my 7603, I promised I tell the story

?

Regards everyone

?

Jean? L? C? Ruelle

?

De?: [email protected] [mailto:[email protected]] De la part de hd1200xlh
·¡²Ô±¹´Ç²â¨¦?: mercredi 14 f¨¦vrier 2024 02:20
??: [email protected]
Objet?: Re: [TekScopes2] New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

?

Congratulations to you and your wife as well as your son on achieving his PHD! You have done a stirling job in creating an environment?to nurture his intrinsic motivation.

?

Well done.

?

Oh, BTW - your write up explaining your current situation presents an interesting read.

?

Thank you.

?

Kind regards.

Roy

?

(just another TEK scope owner and successful diy full recap of a 2465). Take care and stay safe.

?

On Wed, Feb 14, 2024 at 3:07?AM Chuck Harris <cfharris@...> wrote:

Hi,

My transformer winding machine lurks quietly to my left as I sit
at my computer workstation composing this post....
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Chuck, if you ever start back up in the rewinding business I¡¯d like to send you the transformer from my 565 that needs some help. Please keep me in mind. I¡¯d pay more than $100 for it as well.?
Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Congratulations to you and your wife as well as your son on achieving his PHD! You have done a stirling job in creating an environment?to nurture his intrinsic motivation.

Well done.

Oh, BTW - your write up explaining your current situation presents an interesting read.

Thank you.

Kind regards.
Roy

(just another TEK scope owner and successful diy full recap of a 2465). Take care and stay safe.

On Wed, Feb 14, 2024 at 3:07?AM Chuck Harris <cfharris@...> wrote:
Hi,

My transformer winding machine lurks quietly to my left as I sit
at my computer workstation composing this post....

I think it is time that I re-explain my transformer project, and
provide a little insite into its status:

Just prior to starting the winding project, I was at a lull in my
career, with plenty of free time and a desire to do something
worthwhile.

A couple of seemingly unrelated happenings occurred:?
One, I needed a couple of carts for my 7000 series scopes, and two,
my son, caught the math and physics bug at school.

The carts happened to come with a couple of very nice looking
scopes, so I was now the owner of a 545B and a 547... each with a
bad case of the previously unknown to me HV transformer disease.

The project started as a way of scratching my own itches, as they
say.?

Wanting to nourish my high school son's new found interest in math
and physics, I decided that it would be a good idea to involve him
in a fun project that would hopefully stoke his interest while subtly
giving some grounding for his future endeavors.

I started working on making a Farnsworth Fusor.

In spite of having a background in laboratory procedures, and
already owning all of the necessary vacuum equipment, vessels, etc ...
I was stuck on the HV power source necessary to propel the deuterium
nuclei into their fusion state.

The usual Spellman HV power supplies were hard to come by, and way
too expensive for frugal old me, so I decided I would have to make
my own.

The diversion into making replacement transformers for Tek scopes was
my way of learning how to make the fusor's transformer, and getting
my scopes fixed...

In the end, time slipped by, and I never made the fusor, but my son
earned his Phd in nuclear physics, and a few hundred transformers got
wound for you folks on tekscopes and tekscopes2.

I wound several hundred transformers, all manually, for the "princely"
sum of $100 each.

The problem is, when I add up all of the "overhead" involved in the
winding, and divide it into the return, I was working at a deep loss.
Not a very hopeful business model...

I was, I think my wife lovingly coined the phrase, "Wasting my time!"

When I look at all of the side effects of the project, there was much
value, beyond the monetary returns.

1) I, and a few of you, got scopes fixed.
2) My son got his first real work experience.
3) He studied at Carnegie-Mellon, and WUSTL, graduating with
? ?honors.
4) He got his Phd in theoretical physics.
5) And I sorta think the work we did on high vacuum, HV transformers,
? ?and winding machines had a little something to do with
? ?his first internship at Los Alamos National Labs, and later
? ?internship at General Dynamics...

So yes, it was definitely worth doing.

But, in the course of making transformers expectations were created,
and promises were made, and the internet is eternal, so even long
after I am gone, folks are going to still hope that I will wind for
them...

So how to move forward?

The engineer in me felt it was important to make the winding
process more reliably, with considerably less tedium than the
current method, so I created an new automated machine, with none
of the twiddly, adjustments of the old.? The computer took the
place of all of the cams, rubber wheels, and gears I previously
used.

The machine was successful in improving winding accuracy, and
removing most of the tedium, but automation created problems of
its own, owing to the use of stepper motors to handle the motion
required in winding coils...

Prior to retirement, I had an urge to get my projects in order,
and to do as many of the hundreds that had piled up as possible.
Because age was sneaking up on me, I gave higher priority to those
that were becoming harder and harder for me to do...

Now that I am fully retired, so is my wife, so my needs are her
needs, and her needs are my needs, and winding is still low priority.

I work on the machine a little from time-to-time, but it is not
going as fast as I hoped.? I am trying out a roller stylus mechanism
that another fellow rediscovered, and I have high hopes for it.

So, that is where things stand.? Hope for a long gloomy winter,
as I get more indoor work done when I am not outside cutting and
splitting firewood.

-Chuck Harris

On Mon, 12 Feb 2024 10:42:33 -0800 "Group Notification"
<[email protected]> wrote:
>
>
> A new chat has been created:
>
> My beloved 545B has had the fading trace problem for years. Keeping
> the humidity low in the lab has worked for a while, but now it's
> driving me nuts. Love to know if I could get it rewound and for how
> much?
>
> *By:* Conrad Hoffman <choffman@...>
>
> View/Join This Chat ( /g/TekScopes2/chat/12174 )
>
> Do not reply to this message to post to the chat. You can participate
> in chats only through the group's website.
>
>
>
>
>
>
>
>
>
>






Re: New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

 

Hi,

My transformer winding machine lurks quietly to my left as I sit
at my computer workstation composing this post....

I think it is time that I re-explain my transformer project, and
provide a little insite into its status:

Just prior to starting the winding project, I was at a lull in my
career, with plenty of free time and a desire to do something
worthwhile.

A couple of seemingly unrelated happenings occurred:
One, I needed a couple of carts for my 7000 series scopes, and two,
my son, caught the math and physics bug at school.

The carts happened to come with a couple of very nice looking
scopes, so I was now the owner of a 545B and a 547... each with a
bad case of the previously unknown to me HV transformer disease.

The project started as a way of scratching my own itches, as they
say.

Wanting to nourish my high school son's new found interest in math
and physics, I decided that it would be a good idea to involve him
in a fun project that would hopefully stoke his interest while subtly
giving some grounding for his future endeavors.

I started working on making a Farnsworth Fusor.

In spite of having a background in laboratory procedures, and
already owning all of the necessary vacuum equipment, vessels, etc ...
I was stuck on the HV power source necessary to propel the deuterium
nuclei into their fusion state.

The usual Spellman HV power supplies were hard to come by, and way
too expensive for frugal old me, so I decided I would have to make
my own.

The diversion into making replacement transformers for Tek scopes was
my way of learning how to make the fusor's transformer, and getting
my scopes fixed...

In the end, time slipped by, and I never made the fusor, but my son
earned his Phd in nuclear physics, and a few hundred transformers got
wound for you folks on tekscopes and tekscopes2.

I wound several hundred transformers, all manually, for the "princely"
sum of $100 each.

The problem is, when I add up all of the "overhead" involved in the
winding, and divide it into the return, I was working at a deep loss.
Not a very hopeful business model...

I was, I think my wife lovingly coined the phrase, "Wasting my time!"

When I look at all of the side effects of the project, there was much
value, beyond the monetary returns.

1) I, and a few of you, got scopes fixed.
2) My son got his first real work experience.
3) He studied at Carnegie-Mellon, and WUSTL, graduating with
honors.
4) He got his Phd in theoretical physics.
5) And I sorta think the work we did on high vacuum, HV transformers,
and winding machines had a little something to do with
his first internship at Los Alamos National Labs, and later
internship at General Dynamics...

So yes, it was definitely worth doing.

But, in the course of making transformers expectations were created,
and promises were made, and the internet is eternal, so even long
after I am gone, folks are going to still hope that I will wind for
them...

So how to move forward?

The engineer in me felt it was important to make the winding
process more reliably, with considerably less tedium than the
current method, so I created an new automated machine, with none
of the twiddly, adjustments of the old. The computer took the
place of all of the cams, rubber wheels, and gears I previously
used.

The machine was successful in improving winding accuracy, and
removing most of the tedium, but automation created problems of
its own, owing to the use of stepper motors to handle the motion
required in winding coils...

Prior to retirement, I had an urge to get my projects in order,
and to do as many of the hundreds that had piled up as possible.
Because age was sneaking up on me, I gave higher priority to those
that were becoming harder and harder for me to do...

Now that I am fully retired, so is my wife, so my needs are her
needs, and her needs are my needs, and winding is still low priority.

I work on the machine a little from time-to-time, but it is not
going as fast as I hoped. I am trying out a roller stylus mechanism
that another fellow rediscovered, and I have high hopes for it.

So, that is where things stand. Hope for a long gloomy winter,
as I get more indoor work done when I am not outside cutting and
splitting firewood.

-Chuck Harris

On Mon, 12 Feb 2024 10:42:33 -0800 "Group Notification"
<[email protected]> wrote:


A new chat has been created:

My beloved 545B has had the fading trace problem for years. Keeping
the humidity low in the lab has worked for a while, but now it's
driving me nuts. Love to know if I could get it rewound and for how
much?

*By:* Conrad Hoffman <choffman@...>

View/Join This Chat ( /g/TekScopes2/chat/12174 )

Do not reply to this message to post to the chat. You can participate
in chats only through the group's website.
just post to list

 

¿ªÔÆÌåÓý

Done

?
Locked Please don't open "chats" just post to the mailing list

 

Subject says all
New Chat: Is Chuck Harris still winding 545B transformers? #chat-notice

Group Notification
 

A new chat has been created:

My beloved 545B has had the fading trace problem for years. Keeping the humidity low in the lab has worked for a while, but now it's driving me nuts. Love to know if I could get it rewound and for how much?

By: Conrad Hoffman <choffman@...>

View/Join This Chat

Do not reply to this message to post to the chat. You can participate in chats only through the group's website.
Re: Important notice

 

Ok...
Re: Important notice

 




On Friday, January 26, 2024 at 11:14:31 AM GMT+1, David C. Partridge <david.partridge@...> wrote:


IMPORTANT NOTICE - PLEASE READ

Groups.io has been working at re-verifying members of its Groups in response to an spam filtering service called?Spamhaus?affecting users.

This process has been ongoing and those members of Groups.io groups whose e-mail domains are problematic will have already been notified.

This is the bulk of the text of the message I received from Groups.io:

On Saturday January 13th, 2024, an anti-spam service called Spamhaus labeled one of our email servers as a spam sender. This caused any email service that uses Spamhaus to stop accepting email from our server. Because of this, we began a reverification process and sent out reverification emails to a subset of our users on Sunday January 14th. Spamhaus lifted their block on Monday, January 15th, 2024, but we need to continue the reverification process.

You can see which, if any, of your users are affected. Go to the Admin section of your group and look at the Members page. Next to each user's email, there may be a badge with the letters RI or RS. RI means the confirmation/reverification is in progress, but has not been completed. RS means the confirmation/reverification has been successfully completed.

Here are the next steps in the reverification process:

1.???? On Sunday, January 28th, group emails to people in the RI state will be disabled. Messages from moderators and login link emails will still work.

2.???? Until February 11th, people will still be able to reverify themselves and the RI and RS badges will still show up in the Members page.

3.???? After that, members still in the RI state will be removed from groups. The activity log entry will be?Membership - Member Removed, with the added reason of?reverification failed.

?

For domains where no reverifications happened, no invites or direct adds will be permitted going forward. If there is a valid person on one of those domains, they should contact?[email protected]?to have the domain ban lifted.

We apologize for the inconvenience this process may cause, but it is necessary to ensure that we are able to continue delivering group email reliably. Thank you for using Groups.io.

So, if you received an e-mail from Groups.io explaining what is going on , and asking you to verify your e-mail address, and you have not yet done it, please do so.

Re: Tek P6022 current probe

 

John Hunt:


See the TekWiki for specs and manuals on all 3 versions.

The BW depends on r probe used and not the variations _/A/B.
The noise is a bit worse on AM503 than A/B. BW about same on all 3 for comparable porbes.

BW limit 20M on A/B and 5 MHz on 503.

(has links for all 3 for user man, CAL, schematics)

When the A/B 1.55 V silver oxide watch battery dies, you loose ,memory of CAL and last setup.

manuals say CAL is needed after exchange of battery.

Found all My 503A/B are intact, needed batteries. (SR389/390 Silver Oxide)

After replacement all came up fine and NO recal needed.

Tested on a 1T loop with 50 Ohm term resistor and 10 V PG, transient and CAL OK.

One of my probes A6302 rings a bit and needs cleaning or adjustment.

Will check the huge P6303 100 A guns next.


Enjoy,

Jon
Re: Tek P6022 current probe

 

Jon,

I'm curious why you have found that the AM503B is much improved compared to the AM503.??
The manuals show noise spec of the AM503B (with the P6302) being slightly better (<250uA RMS)? vs. <0.3mA "Tangentially measured" for the AM503. The bandwidth worse at 20MHz vs. 50MHz for the AM503 with P6302.

I suspect that you found in practical work the AM503B has been better.

Maybe I'm prejudiced because my AM503B with its internal microcontroller and annoying internal battery stopped working (even after battery replacement) while my all-analog AM503 is still cranking along.

John Hunt
Portland, OR
.?



1e.?
Re: Tek P6022 current probe
From:?Froggie the Gremlin
Date: Thu, 08 Feb 2024 18:36:05 PST

Mike exactly, but AM503B is much improved over 503.

We use both P6302 and the giant P6303 gun for high current

Very useful for SMPS, low PRF current pulses.

But P6302 is very easy to break, and unrepairable, beware of used epay.

Jon
Re: Tek P6022 current probe

 

Mike exactly, but AM503B is much improved over 503.

We use both P6302 and the giant P6303 gun for high current

Very useful for SMPS, low PRF current pulses.

But P6302 is very easy to break, and unrepairable, beware of used epay.

Jon
Re: Tek P6022 current probe

 

AM503 and a P6302 probe?

Mike

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Froggie the Gremlin
Sent: Thursday, February 08, 2024 12:17 PM
To: [email protected]
Subject: Re: [TekScopes2] Tek P6022 current probe

we use the DC HALL effect to 50 MHz tek probe and matching amp for LF DC work.

The small clamp on are never accurate at LF even with 134 amp

j
Re: Tek P6022 current probe

 

we use the DC HALL effect to 50 MHz tek probe and matching amp for LF DC work.

The small clamp on are never accurate at LF even with 134 amp

j
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