[amsat-bb] Re: LEO-satellites-antennas... ?
burns at fisher.cc
Mon Jan 6 14:21:12 PST 2014
Oops. Jeff Moore noticed my typo: Tony's call is AA2TX. I left out the T
On Mon, Jan 6, 2014 at 9:32 AM, Burns Fisher <burns at fisher.cc> wrote:
> 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).
> Burns W2BFJ
> On Mon, Jan 6, 2014 at 2:21 AM, Ben Gelb <ben at 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
>> 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
>> 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,
>> 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
>> 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.
>> On Tue, Dec 24, 2013 at 3:45 AM, Jens Spiess <jens.spiess at bluewin.ch>
>> > Hi all ,
>> > I would like to work the LEO-satellites after a stop of my
>> > 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
>> > ..-
>> > 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 ) :
>> > 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
>> > 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 :
>> > 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 at amsat.org. Opinions expressed are those of the
>> > Not an AMSAT-NA member? Join now to support the amateur satellite
>> > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>> Sent via AMSAT-BB at 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
More information about the AMSAT-BB