[amsat-bb] Re: Egg Beater

Bruce Robertson ve9qrp at gmail.com
Sat Apr 11 11:54:28 PDT 2009


Steve (and the list):

I can add another data-point for you, as I'm playing with minimal
antennas while rebuilding my station. My latest toy is a simple
three-wire groundplane for 70cm made of #10 electrical wire soldered
directly to a male N-connector. This connector is plugged into one
side of an all-weather switching low-noise preamp, and both are in the
hay-loft of a barn, up about 12' from ground, but with wood, roofing
and hay all around. The preamp is connected to the radio by 100' of
LMR-400 coax.

This has been in place for only 24h or so, but I've listened to a 33
deg. pass of FO-29 and some cubesats with quite decent success. The
telemetry of FO-29 (100mw) was audible always; after about 15 deg. I
could comfortably hear a SSB conversation on that bird. SO-50 was not
quite as successful, but I have a TS-2000 so it's sometimes hard to
get a bead on that bird.

Of course, without the preamp, nada, nothing.

Sometimes I worry that we purchase complex and expensive antennas with
preamps and never fully explore the potential of preamps with very
simple, and inexpensive, antennas. This isn't to say that I'm leaving
this g/p as my only antenna, but it provides a simple, cheap and
effective first step and helpful baseline from which to compare
improvements.

I also think it might be a good way to get people into this branch of
the ham hobby. And in  that spirit, about a year ago, I posted a video
of a FT-817 receiving a cubesat beacon with a directly-attached 1/4w
groundplane:

http://video.google.com/videoplay?docid=1251407580465862002

73, Bruce
VE9QRP

On Sat, Apr 11, 2009 at 1:30 PM, Alan P. Biddle <APBIDDLE at united.net> wrote:
> Steve,
>
>>>Once i know i can hear, i will build the uplink
>
> Would that everybody else followed your wise approach!  ;)
>
> Alan
> WA4SCA
>



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