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Re: [ham-help] Fwd: Satcom Antenna Questions




--------- Begin forwarded message ----------

From: "kuentos" <rcc@kuentos.guam.net>
To: "Hans Brakob" <k0hb@juno.com>
Subject: Re: [ham-help] Fwd: Satcom Antenna Questions
Date: Wed, 17 Jun 1998 14:09:21 +1000
Message-ID: <000201bd99a7$5578a500$b20880ca@catheri2>

Hi from Guam Island -
I'd be happy to respond to some of your questions but don't think I can
be a
lot of help on the others.
73 Dick KH2G
-----Original Message-----
From: Hans Brakob <k0hb@juno.com>
To: Ham-Help@makelist.com <Ham-Help@makelist.com>
Date: Wednesday, June 17, 1998 5:20 AM
Subject: [ham-help] Fwd: Satcom Antenna Questions


>
>
>Forwarded message.
>
>From: Rees Roberts <reesr@wi.net>
>
>I am writing this because I think you can help.
>
>I am trying to understand the proper configuration of antennas to use
>these wonderful satellites that are up there now.  But, I also have
>an interest in long distance tropo on 2 meters and 70cm.
>
>Here are the issues:
>
>1) Is there agreement on which manufacturer makes the best antenna
>with regard to long term durability?  How well it stands up to
>the stresses of being exposed to sun, wind, rain, ice, snow etc?

I doubt there will ever be total agreement on antennas as most are better
for one thing than the other so it becomes somewhat an individual
prfernce.i.e. ease of assembly, cost, support etc
>
>2) Does anyone have experience with the suggestions presented in
>the June issue of CQ VHF with regard to mounting cross polorized
>antennas in a "x" rather than a "+"?  Any comments with regard
>to lightning protection that this affords by using metal vs
>fiberglass masts?
>
>3) Would investing in an AZ/EL system merely give access to AO-10 now?
>Will you need the amount of gain from a typical AZ/EL configuration to
>use the new Phase 3D?  In other words, will spending money now give
>over kill capability in the future.

I personally feel you can never go wrong having an AZ/EL capability
unless
you want to build an eggbeater type ant. just to play.  I also must
confess
to being of the persuasion that you can't overkill on antennas.
>
>4) Is an AZ/EL a high maintenance configuration?  I realize it
>depends on how it was put together in the first place, but would
>putting an AZ/EL system on top of a 50 foot tower be crazy?  The
>purpose of doing so would be to use these antennas for long distance
>tropo as well as satellite use.

You pretty well answered your own question there - for your plans it
sounds
good to me as the height is good per your tropo (If your in the wide open
spaces however, you don't need a bunch of height) and the maint. is not a
problem if done right the first time
>
>5) I have read that using a well installed cross polorized satellite
>antenna can and has been used for EME as well.  This depends on working
>the other ham who uses a very large antenna system on their end.  What
>size of antenna (gain) is needed for this for either/both 2 meters and
>70cm?
Not being facetious but it depends on location, conditions,etc.  It's
always
a numbers game as you have to overcome the path loss but the size of his
ant. helps on his receive side also so if he has say +30Db gain it is
there
both comeing and going.
>
>6) I have heard that certain antenna manufacturers antennas are harder
>to put together than others.  Hard on the hands and fingers etc.
>Any experiences?  Suggestions?
>
>7) Knowing that Phase 3D will eventually fly, would a lower tech
>omni antenna system be a more sane answer to the question of what
>antennas to use for satellite usage?  Do you really need the gain?
>
>8) If gain is required, how much is needed as a minimum to work
>AO-10/Phase 3D when it is at the furthest distance from the earth?
>
>9) Do the antenna manufacturers who supply cross polorized antennas
>for satellite use provide the "switcher box" or just the relay
>configuration on the antenna for switching between left hand and
>right hand polorization?  It is very unclear that one would have
>to build a switcher box to control the relays on the antenna.  It
>would be nice to know who makes them and are they all the same?  Are
>there any software solutions which monitor radio signal polorization
>and provide control options?

Switchers seem to vary with the mfr with the better ones asking you if
you n
eed.  Some people prefer to make 2 runs of coax and then there are
swiching
diodes which could be used. (Technology is wunnerfull stuff.)
>
>----
>
>These questions are the result of a couple of months of "looking into"
>the whole satellite antenna issue.  I guess I am in need of
>experienced input.  I have recently joined AMSAT and have explored
>the AMSAT web site.  I also recently purchased a Yaesu FT-847 and
>want to make an informed decision on the issues of antennas for
>satellite usage.  I want to take advantage of the FT-847's multi
>mode capability on the vhf and uhf bands as well as its satellite
>capability.
>
>I realize these issues may have been dealt with before, but I think
>the actual questions posed here would be of benefit to others as
>new users are always coming on board.  My thoughts are beginning
>(after 39 years in amateur radio) to conclude that satellite
>usage is the future of ham radio.  Or at least a large portion
>of it.
>
>I thank you in advance for taking time to answer these questions.
>Please reply to the bulletin board so others may learn as well.
>
>Sincerely,
>
>Rees Roberts - K9UUT
>Racine, WI

>----
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--------- End forwarded message ----------

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