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 <b...@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.spi...@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 > > > > _______________________________________________ > > 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 > > > _______________________________________________ > 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 > _______________________________________________ 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
