Topband: The WD8DSB mini-flag antenna

[Jim Brown]

On 2/24/2021 12:33 PM, Don Kirk wrote:
> As I have mentioned in a few other responses I suspect having the short
> 10 foot feedline helps to negate common mode noise 

YES!

and direct signal
> ingress into the feedline that often haunts us.  I do have one
> recommendation about pattern distortion as follows.  Check to make sure the
> peak and the null of the antenna are in agreement on the signal you are
> direction finding.  If you notice a slight skew (where they don't agree
> with each other), then move away from existing objects and this will
> correct that problem.  I sometimes notice a slight skew when in my backyard
> near my house (looks like the null shifts slightly from where it should
> be), and when I get out away from my house (I move to the sidewalk in front
> of my house) the slight pattern skew goes away.

Yes again! Rudy, N6LF, has shown that even relatively short towers that 
are nowhere near resonance can skew the pattern of a nearby vertical. My 
120 ft tower with the small 3-el straight SteppIR and a long-boom 6M 
Yagi acts as a passive reflector to my Tee vertical that's 200 ft from 
it. Before I added chokes top and bottom to the feedlines of my high 
dipoles, they degraded that Tee.

In general, the most sensitive parts of an antenna's pattern are its 
null(s), because they are the result of the cancellation of two nearly 
equal complex numbers that must be equal in both magnitude and phase.

73, Jim K9YC