Magnetic deflection yoke winding

[Toby Thain]

Hi list,

Has anyone created new magnetic deflection yokes for crts that are
obtained without them? Seems like an ideal application for 3d printing
but yet a daunting project.

Are there any books, recommended project examples, or other resources
that might help in yoke design?

I own a handful of small (3" rectangular) and large (12" circular) tubes
that really deserve to be operated. Obviously internal electrostatic
platers are a lot easier to deal with. I'm an analog electronics learner
about six years in.

Thanks
--Toby

[Adrian Pardini]

Hi there,

I don't know where you live exactly but at least here you can roam
around old electronic shops and repair sites and pick them up very
cheap or free.

Regards

> --
> You received this message because you are subscribed to the Google Groups "neonixie-l" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+...@googlegroups.com.
> To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/141ed8d7-0859-0011-4a3f-23f794e361e8%40telegraphics.com.au.



--
Adrián Pardini

[Toby Thain]

On 2021-02-04 4:10 p.m., Adrian Pardini wrote:
> Hi there,
>
> I don't know where you live exactly but at least here you can roam
> around old electronic shops and repair sites and pick them up very
> cheap or free.
>

Random yokes almost certainly won't fit the tubes I have.

--Toby

[gregebert]

I've dissected quite a few TV's in past years, and the deflection yoke has a rather complex winding pattern, where the windings are closer together at the neck, and spread outward around the funnel-area of the tube. If I recall, there are 4 coils at 90-degree intervals, and the top/bottom coils are series-connected for vertical deflection, whereas the side coils are series-connected for horizontal deflection. Lots of pictures online; notice how many styles there are.

-----------------------------------------

When I was a technician, I swapped the leads on a co-workers computer monitor as a joke and the screen was backwards.

[John Rehwinkel]

Has anyone created new magnetic deflection yokes for crts that are
obtained without them? Seems like an ideal application for 3d printing
but yet a daunting project.

Are there any books, recommended project examples, or other resources
that might help in yoke design?

The tubetime.us website had a nice writeup on making and driving yokes (there was a nice pic of one made out of a toilet paper tube with slots cut in it).

It referenced the book Cathode Ray Tube Displays (1966) which has an entire chapter on the theory, design and building of deflection yokes.  It's a great resource,

and might be what you're looking for.

- John

[Toby Thain]

On 2021-02-04 4:49 p.m., gregebert wrote:
> I've dissected quite a few TV's in past years, and the deflection yoke
> has a rather complex winding pattern, where the windings are closer
> together at the neck, and spread outward around the funnel-area of the
> tube. If I recall, there are 4 coils at 90-degree intervals, and the
> top/bottom coils are series-connected for vertical deflection, whereas
> the side coils are series-connected for horizontal deflection. Lots of
> pictures online; notice how many styles there are.
>

Yes, I don't expect it will be easy.

In my case, at least, I want to use the crt as XY and so I will have
symmetrical coils more or less (unlike tv with its differing horizontal
and vertical frequencies).

--Toby

[martin martin]

this site might offer info

https://oscilloclock.com/

~

mcve...@gmail.com

To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/3010b86f-aded-9d56-ebf7-f392267f801f%40telegraphics.com.au.

[John Rehwinkel]

>>> Has anyone created new magnetic deflection yokes for crts that are
>>> obtained without them? Seems like an ideal application for 3d printing
>>> but yet a daunting project.
>>>
>>> Are there any books, recommended project examples, or other resources
>>> that might help in yoke design?
>>

>> The tubetime.us <http://tubetime.us> website had a nice writeup on

>> making and driving yokes (there was a nice pic of one made out of a
>> toilet paper tube with slots cut in it).
>

> Ah yes, I know TubeTimeUS, I will check it out.

It looks like the site has just been overhauled and I can't find that article any more, but hopefully it's retrievable.

>> It referenced the book Cathode Ray Tube Displays (1966) which has an
>> entire chapter on the theory, design and building of deflection yokes.
>> It's a great resource,
>> and might be what you're looking for.
>

> Thanks John. I have the MIT RadLab publication of that title (more like
> 1948!) but perhaps you mean a different one? If so who is the author?

Here are the details:

Edited by Theodore Soller, Merle A. Starr, and George E. Valley, Jr.

Office of Scientific Research and Development
National Defense Research Committee

Published in the US by Dover Publications, in Canada by General Publishing Company, Ltd., and in the United Kingdom by Constable and Company, Ltd.

Ah, here we are:

"This Dover edition, first published in 1966, is an unabridged and unaltered republication of the work first published by McGraw-Hill Book Company, Inc. in 1948.
It is made available through the kind cooperation of McGraw-Hill Book Company, Inc.
This book was originally published in volume 22 in the Massachusetts Institute of Technology Radiation Laboratory Series."

So it is apparently the same book you already have.

- John

[Toby Thain]

On 2021-02-04 10:40 p.m., 'John Rehwinkel' via neonixie-l wrote:
>>>> Has anyone created new magnetic deflection yokes for crts that are
>>>> obtained without them? Seems like an ideal application for 3d printing
>>>> but yet a daunting project.
>>>>
>>>> Are there any books, recommended project examples, or other resources
>>>> that might help in yoke design?
>>>
>>> The tubetime.us <http://tubetime.us> website had a nice writeup on
>>> making and driving yokes (there was a nice pic of one made out of a
>>> toilet paper tube with slots cut in it).
>>
>> Ah yes, I know TubeTimeUS, I will check it out.
>
> It looks like the site has just been overhauled and I can't find that article any more, but hopefully it's retrievable.
>

TubeTimeUS is on twitter so I can ask directly when I get around to
looking at this.

>>> It referenced the book Cathode Ray Tube Displays (1966) which has an
>>> entire chapter on the theory, design and building of deflection yokes.
>>> It's a great resource,
>>> and might be what you're looking for.
>>
>> Thanks John. I have the MIT RadLab publication of that title (more like
>> 1948!) but perhaps you mean a different one? If so who is the author?

> ...

> So it is apparently the same book you already have.

Thanks for confirming!

--Toby


>
> - John
>

[Instrument Resources of America]

FYI ALL 28 volumes of the M.I.T. Rad Lab series are available as PDF
files somewhere on the net for those who would like to have them.  I
managed to download the complete set. Lots and lots of good information.
If you can't find the volume that you want I 'may' be able to send it to
you.        Ira.

[Mark]

gregebert <greg...@hotmail.com>: Feb 04 01:49PM -0800

> When I was a technician, I swapped the leads on a co-workers computer
> monitor as a joke and the screen was backwards.

I did something similar in college, but easier. The RA (resident advisor)
had just gotten a new color television, of which he was quite proud. I
climbed in his window when he was away, took the back off the set, and
merely rotated the deflection coil assembly 180 degrees. Surprisingly (to
me, anyway), this didn't screw up the convergence much, so the picture
looked fine, just upside down.
~~
Mark Moulding