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Old 5th April 2009, 08:57 AM   #11
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cchean,
It seems from the above posts that this will be an expensive project. At least at my funds level 600.00 dollars will buy a lot of other items.
The good thing is you have a transformer to go by. If you can find someone who winds electric motors for a living in Charlotte at a large electric motor repair facility they should be able to replicate the windings. Mcintosh does not spend a great deal of time closely stacking the windings side by side like you might if you did it. They use very fast spinning bobbins -- usually orlder women doing the work -- and just add wire to a specific number of turns then strap the cores around them and pot.
Any decent winder who measures the wire gauge and counts the turns ratio willl be able to do this. Modern insulation is far superior to what was available in the '70's. Have them place the unit in the VPI tank when finished -- vacuum pressure impregnated-- which will yield a superior unit.
This is something you will most likely need the winder to do on his own time as a side job.
I had one of my-- mc2250 -- transformers done this way at Tampa armature works here in Macon. It turned out perfect. It easily withstands a 3500 volt short to turns test.
If you go this route PLEASE post the winding spec's here on the forum for the rest of us. Tad
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Old 5th April 2009, 03:28 PM   #12
llwhtt is offline llwhtt  United States
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I drew a diagram, scanned it, and tried to attach it but it's too big. So I'll explain it again, think of Stonehenge, a core on each side and one across the top. Or the symbol for Pi, one on each side and one across the top. The sides of the bobbin are longer than the cores are wide, the top core fills the gap. Clear as mud now, right?

Craig
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Old 5th April 2009, 03:37 PM   #13
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Quote:
Originally posted by llwhtt
I drew a diagram, scanned it, and tried to attach it but it's too big. So I'll explain it again, think of Stonehenge, a core on each side and one across the top. Or the symbol for Pi, one on each side and one across the top. The sides of the bobbin are longer than the cores are wide, the top core fills the gap. Clear as mud now, right?

Craig
Craig, could you pls email me a copy of your sketch?

jose_korneluk AT bellsouth.net

Thx,
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Old 5th April 2009, 03:39 PM   #14
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Location: Milwaukee, Wisconsin
http://www.manta.com/coms2/dnbcompany_ccqypkg

Dennis Hoyer, transformer rewinder in Milwaukee, WI.
Been around a long time. Seems to know his stuff. Probably expensive but who knows in this economy.
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Old 5th April 2009, 03:44 PM   #15
llwhtt is offline llwhtt  United States
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Jose you have mail!!!!

Craig
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Old 5th April 2009, 04:29 PM   #16
pjanda1 is offline pjanda1  United States
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I have some connections to Milwaukee, so I was curious and googled Dennis Hoyer. Here is an ad where is lists Mac transformers as something he winds:

http://www.roger-russell.com/autran.htm

pj
www.wildburroaudio.com
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Old 5th April 2009, 05:59 PM   #17
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Quote:
Originally posted by llwhtt
I drew a diagram, scanned it, and tried to attach it but it's too big. So I'll explain it again, think of Stonehenge, a core on each side and one across the top. Or the symbol for Pi, one on each side and one across the top. The sides of the bobbin are longer than the cores are wide, the top core fills the gap. Clear as mud now, right?

Craig
Drawing from Craig...
Attached Images
File Type: jpg mi-200_opt_cropped.jpg (26.3 KB, 542 views)
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Old 12th April 2009, 03:13 AM   #18
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Default Re: Mcintosh amps transformer rewinding, help needed please!

Quote:
Originally posted by cchean

My brother in law has a pair of McIntosh MI-75 monoblock amps

Hi cchean ,

Does your brother in law have those monoblocks yet ???
Or he already sold them ??
What solution have you ( he ) adopted ??

Regards,

Carlos
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Old 12th April 2009, 01:10 PM   #19
cchean is offline cchean  United States
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Hi,

No, he has not sold them. He's waiting for a less expensive repair quote or a replacement for this output transformer. You know anyone?
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Old 12th April 2009, 04:17 PM   #20
nhuwar is offline nhuwar  United States
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Just wondering if Jack at Electra- print would be willing to tackle the job?



Just a thought,



Nick
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