Omnis **may** work in specific situations. KB1HY uses eggbeaters quite well. He is on a 1,000ft hill so has good horizons and presumably RF quiet location. Omnis can also work for very strong downlinks, e.g. ISS (particularly their SSTV transmissions). There's at least one rover using a pair of passive Lidenblads (AMSAT published designs), yes he worked RS44; also he prefers CW and was operating from very remote and RF quiet locations. I've successfully monitored brief portions of Fox-1 series passes from my car (1/4 or 5/8 whip omni) but it was marginal at best. My SATNOGs station uses vertically polarized omnis and performance is mediocre. (Speaking of satnogs, perusing those stations that identify antenna types and looking at their captures, or scheduling a few observations of CAS4A/B, the XW birds, JO97,... may be useful to see how well it works or doesn't in the real world. YMMV.) Omnis in my QTH are a waste of time and effort other than "is the bird on?" (maybe).

Since I don't know the OP's situation, I'd experiment. 1/4 wave verticals are cheap and easy to make and mount temporarily on a mast or pole, or at ground level (WB4APR has written about this for capturing ISS packets). Try it and see how good or bad are the results, particularly receiving the downlinks. If PO-101, AO-91, and CAS4A/B are copied well, it may be worth pursuing further. If not, I'd look at driveway/backyard portable with an Arrow or Elk, or fixed elevation with an azimuth rotator; antennas can be tape measure yagis or WA5VJB Cheap Yagi designs. Upgrade to Az/El and CP antennas if the bug bites.

73 Steve KS1G

On Sun, Oct 17, 2021 at 8:46 PM Jim Walls <jim@k6ccc.org> wrote:

On 10/17/2021 15:32, Richard AG5M via AMSAT-BB wrote:

Specially I asked about the M2 Egg Beater antenna system. No bad words about it, and I now know the M2 Leo Pack is "the" de-facto satellite antenna system.

I'll give you bad words. ANY omni antenna for satellite will be very marginal at best. I built a Egg Beater clone years for use as a packet downlink gateway station for one of the early packet satellites. In several years, if I got ONE packet to decode per day, it was doing well.

A Ham mentioned an antenna I never thought about, the Diamond D130J Discone. It would seem it too, especially given its low cost, is a viable choice for someone just getting their feet wet without spending a lot up front to get started. I have everything I need, other than the antenna.

Same general answer, I would think a discone would not work very well.
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73
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Jim Walls - K6CCC
jim@k6ccc.org
Ofc:  818-548-4804
http://members.dslextreme.com/users/k6ccc/
AMSAT Member 32537 - WSWSS Member 395
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