Hi James,

Yes, there are shunts, which need to be removed. There is/was an article
about how to rewind microwave oven transformers. It was in an ARRL QEX or
similar magazine.

You can find a copy of that article in the Files Section of the yahoo
rfamplifiers group.

http://groups.yahoo.com/group/rfamplifiers/

Pretty much shows you what needs to be done.

Hope that helps...
cheers,
skipp

: James Thompson wrote:
: Has anyone re-wound a power transformer with good results?
: I have salvaged some big transformers from microwave ovens, and cut the
: secondary winding out of it. Then re-wound it with 14 guage till getting
: enough turns to produce about 20 volts. Problem is the thing gets hot even
: without a load on it.
: Is there something I am overlooking? Thanks.