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
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On Tue, Oct 16, 2018 at 5:08 PM Greg D [email protected] 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: [email protected] [email protected] Gesendet: Montag 15 Oktober 2018 22:49 An: [email protected] 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 EasyLog PDA BetaTester WinBollet BetaTester D.C.I. CheckPoint Regione Campania Skype: ik8ozv8520
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