Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old April 26th 07, 11:55 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Apr 2007
Posts: 12
Default Transformer rewinding

Power, plate, audio, chokes. Email me direct for a quote.

--
Gary...WZ1M



  #2   Report Post  
Old May 8th 07, 04:38 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Jan 2007
Posts: 18
Default Transformer rewinding

On Apr 26, 5:55 am, "Gary" wrote:
Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.

  #3   Report Post  
Old May 8th 07, 06:46 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 117
Default Transformer rewinding

On Mon, 07 May 2007 20:38:40 -0700, RapidRonnie wrote:

On Apr 26, 5:55 am, "Gary" wrote:
Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.


Hi,

Because some of us, like in Canada, will end up paying $500 for
shipping/duty/brokerage for $100 worth of lams ;-)

Cheers,

Gregg

  #4   Report Post  
Old May 8th 07, 07:27 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Apr 2007
Posts: 15
Default Transformer rewinding

WHAT'S a lam , short fer lamination? eh?
"Gary" wrote in message
...
Power, plate, audio, chokes. Email me direct for a quote.

--
Gary...WZ1M




  #5   Report Post  
Old May 8th 07, 04:25 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 27
Default Transformer rewinding

RapidRonnie wrote:
On Apr 26, 5:55 am, "Gary" wrote:

Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.


Where can I buy EI laminations for a 100 Watt transformer. I need to
re-wind a couple
of secondary windings on an existing transformer. I don't think I can
remove the existing
laminations without destroying them :-(

Bill K7NOM


  #6   Report Post  
Old May 8th 07, 04:36 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 270
Default Transformer rewinding

Bill Janssen wrote:
RapidRonnie wrote:
On Apr 26, 5:55 am, "Gary" wrote:

Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.


Where can I buy EI laminations for a 100 Watt transformer. I need to
re-wind a couple
of secondary windings on an existing transformer. I don't think I can
remove the existing
laminations without destroying them :-(

Bill K7NOM


De laminating a power transformer is usually pretty easy... That is,
as long as they haven't run a weld bead along the side to prevent
buzzing.

What you do if first knock out the wooden wedge that holds the
lamination stack firmly in the center of the cardboard bobbin.
Then you take a thick(not flexible), sharp, putty knife, and force
it under the tongue of the first lamination that was under the
wedge. The varnish will snap easily. Next, force it under the
top, or bottom leg of the same lamination "E", and move the putty
knife around the full circumference of the "E".

Keep the knife blade flat against the lamination to minimize any
bending. They all should peel off pretty easily.

-Chuck
  #7   Report Post  
Old May 8th 07, 04:46 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 759
Default Transformer rewinding

Bill Janssen wrote:


Where can I buy EI laminations for a 100 Watt transformer. I need to
re-wind a couple
of secondary windings on an existing transformer. I don't think I can
remove the existing
laminations without destroying them :-(


Peter Dahl Co may actually be willing to sell you something... they have
helped me out with parts like that in the past when I have needed them,
and I cannot thank them enough.

But I bet you can get the existing laminations apart with a little hammering
and a little hot water. Once you get one out, they all come apart nicely.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #8   Report Post  
Old May 9th 07, 12:36 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 27
Default Transformer rewinding

Chuck Harris wrote:
Bill Janssen wrote:
RapidRonnie wrote:
On Apr 26, 5:55 am, "Gary" wrote:

Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.


Where can I buy EI laminations for a 100 Watt transformer. I need to
re-wind a couple
of secondary windings on an existing transformer. I don't think I can
remove the existing
laminations without destroying them :-(

Bill K7NOM


De laminating a power transformer is usually pretty easy... That is,
as long as they haven't run a weld bead along the side to prevent
buzzing.

What you do if first knock out the wooden wedge that holds the
lamination stack firmly in the center of the cardboard bobbin.
Then you take a thick(not flexible), sharp, putty knife, and force
it under the tongue of the first lamination that was under the
wedge. The varnish will snap easily. Next, force it under the
top, or bottom leg of the same lamination "E", and move the putty
knife around the full circumference of the "E".

Keep the knife blade flat against the lamination to minimize any
bending. They all should peel off pretty easily.

-Chuck

Well my transformer doesn't have a wooden wedge. It has a plastic bobbin
and the
laminations are tight in the bobbin. Also the laminations were
apparently dipped in
varnish as they were assembled. I finally managed to free two of the I
laminations
using the knife trick, but there is no room for the knife between the E
laminations.

I have another transformer that is the same size, so maybe I can make
one out of two.
I would rather start with a new core though. I want to salvage as much
of the winding
as possible but the core would have to be destroyed. Oh yes the
transformer has to fit
in the original space and the original mounting holes.
Bill K7NOM
  #9   Report Post  
Old May 9th 07, 01:06 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Apr 2007
Posts: 12
Default Transformer rewinding

Never had any "NASTY" laminations. Why add to the price of a rewind with new
laminations? I rewind transformers everyday that people send me. No need to
make any, no time to do it.

--
Gary...WZ1M
"RapidRonnie" wrote in message
ups.com...
On Apr 26, 5:55 am, "Gary" wrote:
Power, plate, audio, chokes. Email me direct for a quote.

--


Why reuse nasty old lams when new are so cheap? You'd be better to
wind something some one wants on a production basis.



  #10   Report Post  
Old May 9th 07, 01:39 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 270
Default Transformer rewinding

Bill Janssen wrote:
Chuck Harris wrote:


Well my transformer doesn't have a wooden wedge. It has a plastic bobbin
and the
laminations are tight in the bobbin. Also the laminations were
apparently dipped in
varnish as they were assembled. I finally managed to free two of the I
laminations
using the knife trick, but there is no room for the knife between the E
laminations.


I cannot imagine anyone working with slimy varnished laminations. The usual
trick is to vacuum impregnate the whole tranny with varnish. They put the
tranny in a pot of varnish, and draw a vacuum. The vacuum draws out any air
between the laminations, and windings. When they release the vacuum, the
varnish is sucked in to fill the vacuous areas.

You should be able to force a sharp blade under the top most "E" lamination
on the free corner. It doesn't hurt the lamination to warp it a bit. The
varnish will be very brittle, and has little tensile strength.

-Chuck


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mod Transformer Jack Schmidling Boatanchors 7 January 6th 07 12:39 AM
Rewinding a rheostat to make it a variable iunductor [email protected] Homebrew 3 September 19th 06 09:03 PM
Xfrmr Rewinding GBrown Boatanchors 0 December 9th 05 07:28 AM
Building a Matching Transformer for Shortwave Listener's Antenna using a Binocular Ferrite Core from a TV type Matching Transformer RHF Shortwave 13 November 3rd 04 08:34 PM
Chicago Transformer Mod Transformer CMS-1 Specs wanted Yardleyite Boatanchors 3 April 7th 04 02:03 AM


All times are GMT +1. The time now is 04:20 AM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017