Topband: RDF

[Luis Mansutti IV3PRK]

Very interesting question Dave...I was just wondering why I never saw any 
comments on this "new" receiving antenna design.
It has been published by KB7GF on QST Oct.2012 and on QEX Sept/Oct. 2012.

It's quite different from the usual small loop types, flags,pennants, K9AY, 
etc...
But contrary to these resistor loaded loops, which always want to work, this 
Shared Apex Loop looks like critical and not so easy to build!

Anyway before going deeply and trying it, I was waiting for the opinion and 
comments of the most authoritative contributors to this reflector, first of 
all Tom, W8JI, to whom we must be always grateful, but also N4IS, NX4D and 
many ithers.

73
Luis IV3PRK


----- Original Message ----- 
From: "David Cole" <g3rcq at yahoo.co.uk>
To: <topband at contesting.com>
Sent: Friday, January 25, 2013 10:27 PM
Subject: Topband: RDF


> How do I calculate RDF – I am currently modelling the Shared Apex Loop 
> antenna recently described in QEX and QST , Not to be confused with the 
> following months article on phased K9AY’s - I have an 8 direction antenna 
> up and running and now wish to add 8 more elements to the array. I will 
> then have three shared apex loops in anyone of 8 directions. I have using 
> Eznec modelled the array and the optimum spacing is around 50 feet and the 
> phase delays 0 100 200 appear to give good F/B and F to side – this leaves 
> me to the original RDF question – in Eznec the Average Gain is 
> calculated – now is the same average gain that the RDF formula needs? It 
> does appear to coincide with figures quoted in the original article for a 
> single array rising to 12.1 db for the three in line array. However if I 
> use the same method and model my 8 Element full size 80m array then the 
> results are not as expected when I try and calculate RDF.
>
>
> Dave
>
> g3rcq
> _________________
> Topband Reflector