Re: [amsat-bb] Arrows and tripods???

["Edward R. Cole" <al7eb@xxxxxxxxxxxxx>]

>From: "Ciemon G0TRT" <g0trtlists@btinternet.com>
>Hi all,
>
>I'm looking to mount my Arrow on a tripod or something similar so that I
>have more hands free, has anyone done any work with this sort of set-up?
>It'll save me re-inventing the wheel!
>
>73.....Ciemon Dunville GØTRT
>ICQ - 6263612
>homepage - www.aprsuk.net

Ciemon,

I just bought an Arrow and am considering the same thing.  Unfortunately,
my 25 year old camera tripod has lost a few parts through the years so it
probably needs replacing.  I did recently mount my 18 inch [46cm] dish on
it [what a disaster].  My tripod uses a 1/4-20 standard thread stud for
mounting a camera.  For the dish, I took a small aluminum plate and tapped
it for the 1/4 inch thread, then used right-angle braces to attach to
vertical piece of plywood that the dish feed arm was bolted to.  The dish
is a bit too large and unwieldy for the tripod.

But if you started with the same flat plate, tapped for the camera mount
stud and used two U-bolts of sufficient size to clamp the Arrow boom, I
think it would do well.  There would be an balance problem with boom being
forward of the attachment and the antenna would be fixed in polarization.

A better approach would be to remove the handle and attach a round tube
over the squarish boom securing it with a bolt.  Then you might slide the
tube inside a short pipe section to make a sleeve or bushing for rotating
the antenna, since polarization changes throught-out a pass.  The sleeve
would be held by two U-bolts to the flat plate.  The tube could be counter
weighted and serve as a handle for pointing.

My solution for the dish, which will see multiple use for AO-40 [2401] and
for microwave rover operation on 10 GHz, is to build a homemade ruggedized
tripod using 2x4 inch lumber for the legs.  I have yet to design the az-el
mount, but am considering adapting a tilting-swiveling vise mount
[Pana-vise].  The counter weight will be the control handle for panning and
tilting the dish.  I have fabricated an aluminum U-shaped open aluminum
chassis for mounting all my electronic components and the dish will attach
to the upright edge.  Thus my FT-817, 10 GHz xvtr-PA-preamp-coax relay, and
later a VHF/UHF PA will all mount below this dish.  I am now thinking on
how to attach the Arrow to provide UHF liaison for microwave shots.

I hope the tripod will be adequate to hold a 4-foot metal Andrews dish.  I
would mount the electronics to the back of this dish. Because of its size
and weight it would need a substantial counterweight.

Hope this gives you some ideas.

Ed
PS: West Coast UO-14 ops:  I am going to tryout the Arrow with the FT-817
tomorrow [orbit #58713; my AOS 1747, LOS 1757 UTC] and maybe the following
pass [1927-1940].  




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