Topband: Re: Topband: Shielded, Balanced Flag

[i4jmy@iol.it]

The balance in a shielded loop is real because the turn inside the loop 
couples to the inside of the shield only.  
On the other hand, the shielded loop suffers by distributed capacitance 
and extra losses whose effects aren't both desired (I'd say not 
tolerable) with antennas that are already inefficient.
Incidentally, the shielded loop works when the signal to be notched is 
E-field dominant but its practical advantage is probably limited to 
this event.

73,
Mauri I4JMY

>  A Flag antenna could be constructed from coax, the
> shields of which would be open at the term. resistor, and grounded at 
the
> feedpoint.  With some retuning, the Flag should work just as it does n
ow,
> but not be partially unbalanced by its surroundings.