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CX2SA > SATDIG 04.06.09 23:00l 215 Lines 6157 Bytes #999 (0) @ WW
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To : SATDIG@WW
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Today's Topics:
1. Re: Elk Antenna ? (Bruce Robertson)
2. Re: Elk Antenna ? (Clint Bradford)
3. Re: Card checkers in Florida (Bill Dzurilla)
4. Chniese Hamsat (jcowens1@xxxxxxx.xxxx
5. Re: Elk Antenna ? (Mark Lunday)
----------------------------------------------------------------------
Message: 1
Date: Thu, 4 Jun 2009 10:35:29 -0300
From: Bruce Robertson <ve9qrp@xxxxx.xxx>
Subject: [amsat-bb] Re: Elk Antenna ?
To: bruninga@xxxx.xxx
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<49657a760906040635t42ff2450oea6652e9a0f2e59@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
On Thu, Jun 4, 2009 at 9:58 AM, Robert Bruninga <bruninga@xxxx.xxx> wrote:
>> I want... a dual band 144/440 antenna on my 85' tower.
>> Can I get away with a fixed elevation of about 30
>> degrees and horizontal polarization?
>
> Three facts say that 30 degrees is the wrong angle.
>
> 1. The amount of time that LEO satellites are above 30 degrees
> is less than 20% of all view times.
>
> 2. You don?t need gain when satellites are above 30 degrees
> because they are much closer and 6 to 10 dB STRONGER.
>
> 3) You DO need gain at the horizon where they are 6 to 10 dB
> WEAKER.
>
> So putting the beam at 30 degrees is counterproductive to LEO
> satellite reception, you will be giving up 3 dB where you need
> it most!.
>
> The answer is to elevate it to 15 degrees.
Once again, Bob's advice is very good. I followed it when I began
satellite operations, and it was quite helpful. Some further notes:
1. This pertains to shorter, and therefore wider beamwidth, antennas
only.Fortunately, these are quite acceptable to communicate with LEO
satellites.
2. You needn't be too fussy about the exact angle. 30% is too high,
but you'll probably not notice the difference between 12 and 17, for
example.
3. With a tower that high, you must include low noise preamps at the
top of the tower. The ones from Advanced Receiver Research and SSB USA
are highly regarded on this list.With that much cable between you and
the antenna, you will be better off with a simple 1/4wave vertical and
a preamp than you would with these antennas and no preamp.
------------------------------
Message: 2
Date: Thu, 4 Jun 2009 06:37:26 -0700 (GMT-07:00)
From: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Elk Antenna ?
To: amsat-bb@xxxxx.xxxx amsat-bb@xxxxx.xxx
Message-ID:
<22093263.1244122646754.JavaMail.root@xxxxxxxxxxxxx.xxx.xx.xxxxxxxxx.xxx
>
Content-Type: text/plain; charset=UTF-8
>I want to mount the Elk dual band 144/440 antenna up on my 85' tower.
Consider Loc-Tite(tm) for all of the elements ... I'd rather see you mount a
more durable, meant-to-be-mast-mounted dual-bander - like a Cushcraft unit.
Clint Bradford
909-241-7666
----------------------------------
Clint Bradford, K6LCS
http://www.clintbradford.com
------------------------------
Message: 3
Date: Thu, 4 Jun 2009 07:11:39 -0700 (PDT)
From: Bill Dzurilla <billdz.geo@xxxxx.xxx>
Subject: [amsat-bb] Re: Card checkers in Florida
To: amsat-bb@xxxxx.xxx
Cc: w4as@xxxxxxxx.xxx
Message-ID: <734200.29172.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Sebastian,
Don, W3AZD, lives less than a mile from me, just off the Nob Hill Rd. exit
(Exit 3) on I-595 in Broward. He is an ARRL checker and would be happy to
check your cards. Tell him I sent you.
73, Bill NZ5N (now in Europe as OM9ACA)
------------------------------
Message: 4
Date: Thu, 4 Jun 2009 15:38:37 +0000 (UTC)
From: jcowens1@xxxxxxx.xxx
Subject: [amsat-bb] Chniese Hamsat
To: amsat-bb@xxxxx.xxx
Message-ID:
<605662262.2073831244129917473.JavaMail.root@xxxxxxx.xxxxxxxxxx.xx.xxxx.
xxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8
I haven't been following the satellite news lately and wonder what the status
is of the impending launch of a Chinese Hamsat that I read about a while ago.
John Owens - N7TK
------------------------------
Message: 5
Date: Thu, 4 Jun 2009 11:52:32 -0400
From: "Mark Lunday" <mlunday@xx.xx.xxx>
Subject: [amsat-bb] Re: Elk Antenna ?
To: <harry@xxxxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Message-ID: <001101c9e52c$79146030$6b3d2090$@xx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
Regarding the 30 degree fixed elevation...I can tell you this will work just
fine from my experience. The beanwidth is not like a 10 element yagi with
sharp drop offs that require precise aiming. You should be good to go.
Mark Lunday
WD4ELG
wd4elg@xxxx.xxx
http://wd4elg.net
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of harry@xxxxxxx.xxx
Sent: Wednesday, June 03, 2009 6:54 PM
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Elk Antenna ?
Guys,
?
I want to mount the Elk dual band 144/440 antenna up on my 85' tower.
?
Can I get away with a fixed elevation of about 30 degrees and horizontal
polarization?
?
I recognize that this is a compromise, but I'd like to avoid the?additional
complexity of dealing with an azimuth rotor.
?
Any thoughts appreciated.
?
73 de harry, W6DXO
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End of AMSAT-BB Digest, Vol 4, Issue 259
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