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7834 HT transformer rewind?

 

I may have located a company in UK that can handle the rewinding of these
transformers.

It won't be dagger cheap - they gave me a ball-park figure of about GBP100
plus tax and delivery, but that was without seeing the winding
specification which I have just emailed to them. I'll let you know when
they say once they've had a chance to look at the document.

David

Brian
 

That is good news to hear , some years ago I went to a company that said they could wind a 549 transformer , in todays money it cost about the same -- but it didnt work when I got it ?? . I was never able to discover why
Brian

On Saturday, 19 October 2019, 13:14:02 BST, David C. Partridge <@perdrix> wrote:

I may have located a company in UK that can handle the rewinding of these
transformers.

It won't be dagger cheap - they gave me a ball-park figure of about GBP100
plus tax and delivery,  but that was without seeing the winding
specification which I have just emailed to them.  I'll let you know when
they say once they've had a chance to look at the document.

David








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Mlynch001
 

David,

I would be interested in a quote for the HV transformer of the Type 576 as well. The winding specs are readily available, unfortunately, the ferrite cores are not. There are very likely some buyers for a "factory built" replacement HV transformer for the 576 as well. Just throwing that out there, as this subject has already been thoroughly discussed in another thread.

--
Michael Lynch
Dardanelle, AR

Chuck Harris
 

The 7834 transformer is an all-in-one transformer, and as
such it has all of the power supply windings, and the EHT
on a single core.

It is a cornucopia of wire sizes, taps, tapes, and wedges.

The winding machine would have to be started and stopped
two dozen times before the entire winding would be finished.

There are many in the 7000 series that are similarly done,
among them the 7904, 7934... The "A" scopes went back to
the separate Power and EHT style of design.

-Chuck Harris

Mlynch001 wrote:

David,

I would be interested in a quote for the HV transformer of the Type 576 as well. The winding specs are readily available, unfortunately, the ferrite cores are not. There are very likely some buyers for a "factory built" replacement HV transformer for the 576 as well. Just throwing that out there, as this subject has already been thoroughly discussed in another thread.

greenboxmaven
 

Has anyone investigated the compatability of transformers or cores from Tektronix televison studio equipment? I really don't care for the idea of trashing that gear, but I can't imagine any of the 480I archival and transfer studios wanting the vacuum tube versions of them. In addition to the transformers, the CRTs (IF they are not run to death) might be adaptable to replace smashed, missing, or dead ones, and the knobs are compatable with many older scopes. Maybe some conversations with broadcast engineers could locate a few to find out. Also, I heard years ago Conrac was the television division of Tektronix. Was this true? I do know there were gazillions of Tektronix wavefrom monitor/ 8 inch Conrac picture monitor combos in factory built rack trays used in TV studios.

Bruce Gentry, KA2IVY

On 10/19/19 11:18 AM, Mlynch001 wrote:
David,

I would be interested in a quote for the HV transformer of the Type 576 as well. The winding specs are readily available, unfortunately, the ferrite cores are not. There are very likely some buyers for a "factory built" replacement HV transformer for the 576 as well. Just throwing that out there, as this subject has already been thoroughly discussed in another thread.

Mlynch001
 

Chuck,

You are a cornucopia of knowledge!

Thanks!

--
Michael Lynch
Dardanelle, AR

Vintage Test
 

Hi Dave,

I have a pair of 7834’s with duff HV transformers - always the EHT winding - and remember someone on the old Yahoo group had successfully rewound one of these. However, I have called and emailed several manufacturers of ‘custom’ transformers, only to be knocked back when they saw the complexity of the winding details. I toyed with the idea of removing the EHT winding and driving a mosFET and one of those cheap Chinese HV transformers from the inverter drive - seem to think it’s about 26KHz - but never got around to it🙁

Cheers,
Mel

--
you can never have enough oscilloscopes, DMMs, valve testers or soldering irons . . .

Craig Sawyers <c.sawyers@...>
 

Hi Dave,

I have a pair of 7834?s with duff HV transformers - always the EHT winding - and remember someone
on the old Yahoo group had successfully rewound one of these.
I remember that. Whoever it was posted some pictures of the process.

Aha - found my copy of it. A 3-page pdf dated March 2015.

Must have got it from the pictures files on Tekscopes.

Craig

Craig Sawyers <c.sawyers@...>
 

OK - it was Karin in 2015. The whole thread is here
https://groups.io/g/TekScopes/topic/7655243#114241

So somewhere lurking in the picture archive is the rewind photos he took.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig Sawyers
Sent: 20 October 2019 10:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

Hi Dave,

I have a pair of 7834?s with duff HV transformers - always the EHT
winding - and remember someone on the old Yahoo group had successfully rewound one of these.
I remember that. Whoever it was posted some pictures of the process.

Aha - found my copy of it. A 3-page pdf dated March 2015.

Must have got it from the pictures files on Tekscopes.

Craig



Craig Sawyers <c.sawyers@...>
 

I've added the photos that Karin took of his 7934 (which IIRC is the same as the 7834) rewind. They
do not seem to have survived the migration to io.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig Sawyers
Sent: 20 October 2019 10:51
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

OK - it was Karin in 2015. The whole thread is here
https://groups.io/g/TekScopes/topic/7655243#114241

So somewhere lurking in the picture archive is the rewind photos he took.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Craig Sawyers
Sent: 20 October 2019 10:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

Hi Dave,

I have a pair of 7834?s with duff HV transformers - always the EHT
winding - and remember someone on the old Yahoo group had successfully rewound one of
these.

I remember that. Whoever it was posted some pictures of the process.

Aha - found my copy of it. A 3-page pdf dated March 2015.

Must have got it from the pictures files on Tekscopes.

Craig





Dave Seiter
 

I thought the io transfer grabbed everything; is there a known subset it ignored for some reason?
-Dave

On Sunday, October 20, 2019, 03:42:08 AM PDT, Craig Sawyers <c.sawyers@...> wrote:

I've added the photos that Karin took of his 7934 (which IIRC is the same as the 7834) rewind. They
do not seem to have survived the migration to io.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig Sawyers
Sent: 20 October 2019 10:51
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

OK - it was Karin in 2015. The whole thread is here
https://groups.io/g/TekScopes/topic/7655243#114241

So somewhere lurking in the picture archive is the rewind photos he took.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Craig Sawyers
Sent: 20 October 2019 10:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

Hi Dave,

I have a pair of 7834?s with duff HV transformers - always the EHT
winding - and remember someone on the old Yahoo group had successfully rewound one of
these.

I remember that. Whoever it was posted some pictures of the process.

Aha - found my copy of it. A 3-page pdf dated March 2015.

Must have got it from the pictures files on Tekscopes.

Craig





Craig Sawyers <c.sawyers@...>
 

Things certainly disappeared from Yahoo pre grab. I had a photo album with the internal photos of my
7912HB and some performance images, that went the way of dust years before the grab.

Maybe Karin's rewind photos went the same way.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave Seiter
Sent: 21 October 2019 07:15
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

I thought the io transfer grabbed everything; is there a known subset it ignored for some reason?
-Dave
On Sunday, October 20, 2019, 03:42:08 AM PDT, Craig Sawyers <c.sawyers@...>
wrote:

I've added the photos that Karin took of his 7934 (which IIRC is the same as the 7834) rewind. They
do
not seem to have survived the migration to io.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Craig Sawyers
Sent: 20 October 2019 10:51
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

OK - it was Karin in 2015. The whole thread is here
https://groups.io/g/TekScopes/topic/7655243#114241

So somewhere lurking in the picture archive is the rewind photos he took.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Craig Sawyers
Sent: 20 October 2019 10:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 HT transformer rewind?

Hi Dave,

I have a pair of 7834?s with duff HV transformers - always the EHT
winding - and remember someone on the old Yahoo group had
successfully rewound one of
these.

I remember that. Whoever it was posted some pictures of the process.

Aha - found my copy of it. A 3-page pdf dated March 2015.

Must have got it from the pictures files on Tekscopes.

Craig