archive: SETI Re: Argus: Helix antenna

SETI Re: Argus: Helix antenna

MarcusJohn@aol.com
Tue, 1 Jun 1999 09:48:33 EDT

In a message dated 5/31/99 10:20:46 PM Eastern Daylight Time,
rjfear@adaptv.com writes:

> Adrian,
>
> I have some information from building two of them. Most of it came from
> ARRL manuals and bending lots of copper tubing. Would you prefer I email
> attach them or set them up for you to FTP?
>

I have also been thinking about the helix antenna. As far as I know, nobody
has tried to optimize arrays of helices for anything but gain.

What I have been thinking about doing is to simulate an array of helices in
NEC, and then run a bunch of simulations with different helical spacings to
see if we can optimize gain and minimize half power beam width. I suspect
that wider spacing with proper phasing will minimize the beamwidth, somewhat
like a phased array radar.

I have been able to simulate a helix, and it is easy to generate an array of
helices in NEC2, but I have not done the work yet to phase these arrays into
one antenna. This will involve writing a few lines of code into NEC2. And to
tell you the truth, I don't understand how to read the NEC2 output properly.
Does anyone want to help, or someone who has a better NEC to work with? NEC2
is limited to 1300 segments or something like that. For a proper simulation
we will probably need more segments.

John.