Topband
[Top] [All Lists]

Topband: Flag Transformer Design

To: <topband@contesting.com>
Subject: Topband: Flag Transformer Design
From: W8JI@contesting.com (Tom Rauch)
Date: Sun, 21 Nov 1999 11:22:55 -0500

> When I connected the shield and the pot core to earth ground
> the capacitance between windings measured as 1/10 of 1 pf.
> 
>  Comments???

Yes, you are using a "Faraday shield" the way it should be used 
when you ground it to a separate ground.

It isolates the primary to secondary for parallel current by forming a 
barrier.

If you ground the Faraday Shield to the common of the antenna or 
feedline, as is often seen, you'll find it almost always makes things 
worse..not better!

That's why the shield of a shielded loop should ideally go to it's 
own separate good earth ground right at the antenna.


73, Tom W8JI
w8ji@contesting.com



--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com


<Prev in Thread] Current Thread [Next in Thread>