[amsat-bb] Re: LEO-satellites-antennas... ?

[Ben Gelb]

Hi Jens -

I bought 3 of the antennas.us QFH antennas a few years ago.

- 1 70cm QFH (passive)
- 1 70cm QFH w/ preamp
- 1 2m QFH (passive)

I live in an apartment and have limited space for big antennas, so I
thought these would be a good fit. They're very compact, and easy to set up
on my flat roof.

Over the couple of years I used them, I made some QSOs on FO-29 and others
(I don't have 70cm TX, so primarily used 70cm for receive only). Worked OK,
but found that I needed pretty high elevation passes to have success.

I think the QFH throws most of the energy straight up (broad pattern, but
not a lot at the low elevation angles).

Then, the 2m antenna turned into an open... turned out to be a broken
solder joint inside of the antenna (not easy to get at it to fix, either...
needed a hacksaw, as the antenna is sealed in a plastic tube).
Then, the preamp in the 70cm ant stopped working. Haven't bothered trying
to fix.

Lately, I switched to a small 6-el "cheap yagi" (WA5VJB design) for 70cm
receive, mounted on a motorized pan/tilt for security cameras... SO MUCH
better (and not a "long" yagi by any means either). So there is definitely
a compromise going to the omni-type ants.

If i'd continued down the fixed/omni path, I think I would have liked to
try a simple 1/4 vertical as a baseline - my hunch is it may have performed
at least as well as the QFH, since there would be better coverage of the
lower elevations (where the sat is farther away). The "Lindenblad" looked
interesting too, but complicated to make yourself.

73,
Ben



On Tue, Dec 24, 2013 at 3:45 AM, Jens Spiess <jens.spiess at bluewin.ch> wrote:

> Hi all ,
>
> I would like to work the LEO-satellites after a stop of my amsat-activities
> since 12 years now again .
> But I have changed my QTH in the Swiss-Alps and the weather is at a lot
> of times of the year very roughly . (A lot of snow, ice and storms ...)
>
> So , I want NOT use long YAGI-Antennas with rotators again – ... or so on
> ..-
> because all was always and always – also the rotator – demaged .
> So I am interested to use – maybe – only fixed antennas for 2m/70cm like
> the
> edgbeater from M2 or the other like this (I found it in the internet ) :
>
>
> http://www.antennas.us/store/p/229-UC-4364-328-UHF-Amateur-Satellite-Antenna.html
>
> BUY BOTH as KIT :
> =================
> UC-AMSAT-KITP, 2 m / 70 cm Passive Amateur Satellite Antenna Kit
> Item #: UC-AMSAT-KITP-VHFL-UHFR-N-VHF-10ft-UHF-10ft
> Availability: approx. 2 weeks
> Usually ships In approx. 2 weeks
> Price: $250.00
>
> But they will always use with low-noise 20 dB-gain-Preamplifieres installed
> on the top of my house directly after the antennas .
>
> Can anybody tell me , which antenna-types will get the best results as
> fixed-mounted ones or have anybody experiences or maked a compare
> between these antennas ...?
>
> Like this :
>
> http://www.antennas.us/store/p/229-UC-4364-328-UHF-Amateur-Satellite-Antenna.html ???
> or these :
> http://www.m2inc.com/pdf_manuals/EB-144%20_%20RK2M.pdf  ???
>
> Which of them will be better work for LEO-communication ...??
>
> 73 de Jens / HB9JOI
>
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