I was actually reading up on Bob Bruninga's analysis (earlier in this thread) of why a fixed elevation yagi would have more than adequate performance for majority of the LEO passes, when you sent me the info below. Thank you!
Comment: based upon what you sent in a separate message, the picture of a "mean" looking in-service 5-element model, if the antenna is that small of a mass, a second revolute joint for Elevation control with positioner could be practical - if some parts from hobby robotics / class room robotics projects were able to be used. Of course it would increase the cost somewhat and complicate wiring - but would result in true elevation over azimuth control.
73 de N3RDX
On Tue, May 29, 2012 at 4:49 PM, Ted [email protected] wrote:
Hi Samudra, consider a better alternative to the 'egg beater': Moxon turnstile....much better performance. I will e-mail the article from qst. Also, consider an Elk 2m/440 yagi at a fixed elevation and on a Radio Shack rotor.
GL, Ted, K7TRK
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Samudra Haque Sent: Tuesday, May 29, 2012 1:18 PM To: Edward Cole Cc: [email protected] Subject: [amsat-bb] Re: EggBeater
Hello, can I ask a question related to this several-years old thread? At George Washington University, this fall we will be on the air and are buliding up an amateur radio club ground station from scratch. Currently we are collecting equipment, cables, etc., while we wait for the construction to begin on a new door in the interior of a third floor class room space to let us use that area as a "radio room" or something like that. At my home QTH, I'm testing out the radios we can use, and would like to both receive and transmit - with omni antennas (e.g., eggbeaters, QHA ) and later AZ-El yagis.
Assuming an LNA is used at the antenna for the RX path, would it be practical to use that same omni for uplink? What are the recommended power settings for such an uplink for any of the recent amsats?
If there was a constraint (for the summer into fall) of operating in a limited visibility area, and approximately 50 sq. ft of open access (i.e., 21 ft monopole mast with open free area about 4 ft dia.) would that be adequate for any sort of uplink antenna? The good thing is that the ultimate location of the club station antenna farm is huge, but for now this is what we have. I'm open to AZ-El positioners but the mast loading limit is pretty small for now.
Any suggestion welcome.
Regards,
Samudra N3RDX
On Thu, Apr 16, 2009 at 9:50 PM, Edward Cole [email protected] wrote:
Drew,
Thanks for the document on this antenna. I was going to try resizing the 2m Lindenblad design of Tony's but this will be a snap for me. I have 1/8-inch rod elements from an old Cushcraft yagi that disintegrated long ago and have some 1/2-inch sched-40 aluminum pipe (7/8 inch OD) that will work fine for the vertical. I can get the PVC from my local building supply. Only need to order ferrites from Mouser. Since I will place a 432 preamp at the antenna a short run of RG-58 or mini-8 will suffice. I probably will make some variation in the materials used. I did that on the 2m Lindenblad (not assembled, yet).
73, Ed - KL7UW
At 08:02 AM 4/16/2009, Andrew Glasbrenner wrote:
Consider trying AA2TX's excellent parasitic lindenblad design. Unlike
the
overpriced eggbeater, it puts the gain on the horizon where it is
needed,
and is circular across the pattern. The parts mostly are from your local hardware store, and in Tony's typical fashion, it is simple to assemble
and
works well.
73, Drew KO4MA
----- Original Message ----- From: "Bill Dzurilla" [email protected] To: [email protected] Sent: Thursday, April 16, 2009 11:56 AM Subject: [amsat-bb] Re: EggBeater
Steve,
I have both a commercial and a homebrew Eggbeater and am disappointed
with
both, especially in light of its rather high price. Connected to my IC-7000 via an ARR mast-mounted preamp, performance is far less than
with
an HT and an Arrow. Guess an omni can't cut it, at least not from my
QTH.
Maybe if I could get it up higher, clear of all roofs, it would do
better.
I can make contacts at relatively high sat elevations, but can do
just
as
well with a $10 dual band ground plane. My friend has an Eggbeater
and
the same preamp at a clearer QTH, and he hears substantially better,
down
to 10 degrees elevation in some directions.
Good luck and 73, Bill NZ5N
Hi Steve,
It is surprising to read that you are not hearing
anything. I have
repeatedly used a 2m and 70cm Eggbeater for the sats
and have had no
problem hearing things. No pre-amp.
I was using a short cable (e.g. less than 10 meters).
The rigs I
used were a FT-736r (deaf) and a FT-847 (so-so).
73,
Dave
Sent via [email protected]. Opinions expressed are those of the
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Sent via [email protected]. 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 [email protected]. 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 [email protected]. 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