[amsat-bb] Antenna for 1200MHZ for satellites and EME Activity?

[Scott]

Helicals are fun to build, both as RHCP directional antennas or LHCP for
use as a dish feed.

Here is the online calculator that I've always used:

http://jcoppens.com/ant/helix/calc.en.php

... and PVC pipe is very handy to build with since it can be cut, joined, &
drilled so easily.

-Scott,  K4KDR


=========================

On Tue, Oct 16, 2018 at 5:08 PM Greg D <ko6th.greg at gmail.com> wrote:

> For satellite use (not as likely for EME), I've had good results with a
> simple helix antenna.  They are easy to build, and pretty tolerant of
> slight inaccuracies in manufacture (much more so than a Yagi).  There
> are a lot of designs and calculators for designs on the Web, but I can't
> seem to find the one I used for mine.  Ed KL7UW, and Clare VE3NPC, were
> great mentors in the process.  If I recall, the key dimensions are
> making one turn of the helix one wavelength long, and the pitch between
> turns spaced to get a 12.5 degree angle.
>
> Of considerable help in construction, anything that's inside the helix
> is pretty much irrelevant to its performance, so long as it doesn't
> touch the helix windings.  I used a metal rod, then some zip ties to
> support the winding every so often, one thick tie around the rod
> extending out, then a small tie to attach the winding to the first tie.
> Some use plastic pegs into a wooden dowel.  Be creative and make
> something up.
>
> The reflector and feed point is a flat sheet of metal with an N
> connector attached.  Angle the first 1/4 turn at a shallow angle for
> impedance matching, and you're done.
>
> Good luck!
>
> Greg  KO6TH
>
>
> Patrick Leicht wrote:
> > Hello Enzo,
> >
> > I'll try this week a homemade 24 element yagi (DL6WU design). I think
> this antenna is only for sats an for EME to small with my 10W from the
> TS-2000X.
> >
> > 73 de Patrick  (DL3MLP)
> >
> > -----Ursprüngliche Nachricht-----
> > Von: vimone at alice.it <vimone at alice.it>
> > Gesendet: Montag 15 Oktober 2018 22:49
> > An: amsat-bb at Amsat.org
> > Betreff: [amsat-bb] Antenna for 1200MHZ for satellites and EME Activity?
> >
> > Hello,
> > please anybody can suggest me an
> > array antenna for 1200MhZ for satellites and EME Activity?
> > Thanks
> >
> > 73 de Enzo IK8OZV
> > EasyLog 5 BetaTester
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