Oops. Jeff Moore noticed my typo: Tony's call is AA2TX. I left out the T before.
On Mon, Jan 6, 2014 at 9:32 AM, Burns Fisher burns@fisher.cc wrote:
Ben,
Have you looked at the AA2X Lindenblads? Tony has designed both a 70cm Lindenblad (with a single dipole driven element and parasitic elements for the rest) and a 2m Lindenblad (with phasing using lengths of 75ohm (yes, 75!) coax. I'm not terribly skilled at building stuff, but I was able to build the 70cm version, and I am just starting the 2m version. Not terribly hard and using easily-available materials. The only somewhat specialized items are ferrites, cable, and connectors. Most of the rest you can get at your local hardware store.
The Lindenblads have a nice pattern too: highest gain toward the horizon somewhat less overhead (where the bird is closest).
73,
Burns W2BFJ
On Mon, Jan 6, 2014 at 2:21 AM, Ben Gelb ben@gelbnet.com wrote:
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@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...
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...
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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Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb