Topband: RDF for Transmit 4 Square vs 8 Circle Array

[donovanf at starpower.net]

Hi Chuck, 


I have both a full size transmitting 4-square and a W8JI BSEF 
8-circle array using 25 foot low impedance passive umbrella 
verticals. There are no active electronics in the W8JI's BSEF 
8-circle array, unlike the Hi-Z array. 


While the transmitting array is an excellent receiving antenna, 
I can verify that the 8-circle is superior in some situations 
apparently because of its much narrower beamwidth. I'm sure 
the Hi-Z array would provide similarly excellent performance. 
I have completed QSOs with very weak DX stations that could 
not have been completed with the 4-square or my Beverages. 


For a contester its very important to have an alternative antenna to 
the 8-circle array. Its 3 dB beamwidth is so narrow (about 45 
degrees) that you won't hear some off-azimuth callers. Normally 
I use the Beverages for receiving and switch to the 8-circle array 
only when needed. 


73 
Frank 
W3LPL 






----- Original Message -----

From: "Chuck Dietz" <w5prchuck at gmail.com> 
To: topband at contesting.com 
Sent: Monday, October 16, 2017 6:26:41 PM 
Subject: Topband: RDF for Transmit 4 Square vs 8 Circle Array 

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 
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