[TenTec] Re: EMI (was Argonaut 505 - The Answer)

[Bill Fuqua]

I tried to sent the following with attachment to clear up the confusion 
between the end bells or clam shells ( ferrous metal magnetic shields and 
shorted turns. But due to size it bounced. I had pictures of a transformer 
with shorted turns.  If you want to see the pictures email me and I'll send 
you the attachments.

Mu metal is expensive and unnecessary. It is great for a light weight
shield but soft steel (hot roll sheet) an 1/8 inch thick will do very well.
What you need is to use the steel.  Clam shell shields are not
shorted turns but iron (soft steel)  shields, shorted turns are thick pieces of
copper strap that are wrapped around the core and windings and soldered
together. These are the same width as the windings of the transformer
and must be formed to be tight against the core and windings. A gap
usually allows leakage.
	Attached are photos of shorted turn. Low resistance is absolutely 
necessary. The copper strap is overlapped and then soldered to get lowest 
resistance in the connection as possible


73
Bill wa4lav