Topband: RDF for Transmit 4 Square vs 8 Circle Array

[Gary Smith]

Chuck,

I don't have the experience with both that 
Dennis has but I have had the same 
beneficial results with the HI-Z 4-8Pro Rx 
antenna which I'm using 8 active short 
antennas. Sometimes I can null another 
station almost totally out of the picture. 
There's not that much gain compared to the 
sloper but the S/N is far better on the 
HI-Z. I consider it essential. 

I understand you're talking about Tx as 
well but I wanted to share my similar Rx 
results as Dennis has had.

73,

Gary
KA1J

> Chuck
> 
> Having used both at a number of stations, I can speak with some 
> experience here.
> 
> The biggest virtue I have found of an 8 Circle array is the ability to
> put a bothersome station or noise in a null.  Most of the time, you
> can hear a station in the 4-square beamed direction as well on the
> 4-square as on the 8 Circle.  You might even be able to put a
> bothersome station or noise in a null with the 4-square, but now he
> doesn't hear you either. The 8 Circle allows you to steer the null and
> maybe find a spot where the SNR is better, and I've found both as
> valuable as the direction of maximum gain.
> 
> So, yes, you can hear things on an 8 Circle that you might not hear on
> a 4-square, but to me its more a question of nulls (of both other
> signals and noise) rather than a stronger signal.
> 
> Dennis W1UE
> 
> On 10/16/2017 2:26 PM, Chuck Dietz wrote:
> > I was always told that, if one had a 4 square, there would be no
> > need for a receive array. I am finding this to be untrue when
> > looking at the list of RDFs. (Receive Directivity Factor) I have
> > snooped through the archives reading about RDF. Can anyone verify
> > this from actual experience?  Can you actually hear stuff on an 8
> > Circle that can't be heard on the transmit 4 square? I would think
> > the difference might be more than marginal with the difference in
> > RDFs of 2.48 db.  I'm not sure of the difference in takeoff angles.
> > That could be important too. As a practical matter, the 8 Circle  is
> > huge and expensive for a single band antenna...
> >
> > Chuck W5PR