Possible transformer rewind?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Rick Williams by way of Terry Fritz <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>

Hi list,
 
Must be my time for transformers. :)
Got two trannys at a yard sale today. Husband died and the wife sold all his
ham radio equipment. Except for these 2 trannys. Got both for 20 bucks!
 
And very sizable ones at that, identical, 38 lbs, dry (not potted) "E" frame
type. Each has 2 primaries, 120vac. Has 3 secondaries, two 120vac out -at- 8 amps
each and one 10vac -at- 6 amps. The current ratings were taken from the wire size
of each secondary. The cross-section of the middle leg of the "E" is 7.36 sq
in. Using the formula VA = ( A / 0.16 ) ^ 2 I get 2116 VA. That's about right
for the currents indicated by the wire size.
 
Cross-section ... Width = 2.3 in. Length = 3.2 in.
(length is determined by the number of laminations)
 
VA = ( A / 0.16 ) ^ 2
VA = ( 7.36 / 0.16 ) ^ 2
VA = 46 ^ 2
VA = 2116
 
These look like some kind of isolation transformer with a secondary for a 12
volt supply or step-up / step-down transformers. 
 
I already have an isolation transformer for my scope and never really had any
use for isolation elsewhere nor do I have need for step-up or step-down. 
 
So I'm "thinking" of rewinding them. I've wound trannys before and know what
I'm in for, somewhat, since I've wound many low voltage high current ones. The
hardest part has always been aquiring the laminations or making them. I can
join all the laminations from both trannys to form one large one. The
cross-section would be 14.72 sq in.
 
VA = ( 14.72 / 0.16 ) ^ 2
VA = 92 ^ 2
VA = 8464
 
Even with losses of a little over 10% I may be able to squeeze out 7500 VA.
Wire isn't a big issue and neither is the time involved since I can now wind a
custom tranny. Primary 240 vac .... Secondary 15kv -at- .5 amps comes to mind. So
far it looks like the coils needed should fit fine with room to spare for the
insulation necessary. (polypropylene sheeting 1/8" to 3/16" thick)
 
But I'm concerned about the shape the cross-section would be at 2.3" x 6.4"
I've generally tried to keep the cross-section as square as possible on
homebrew trannys.
 
 
Rick Williams
Salt Lake City