[amsat-bb] Re: Looking for a G3RUH dish

[Bob Bruninga]

> Regarding your Cu wire dish... you might look at 
> the Tek Sharp dishes as an easier alternative to "rolling your own."  

We are after absolute minimum wind drag.  I don't think the Tek dish would
survive accurate tracking while driving along the interstate at 70 PMPH to
catch a balloon.  And we want it to be a good 3' by 4' dish...  Need the
gain for the tiny wifi video link...

Bob
 


I picked one up on ebay about a year ago and put it in my attic... waiting
for amsat-dl :-)

http://www.plumdragon.com/teksharp/hr_AO-40_products.htm

Drew,
I have a spare PF dish about 60 cm, but it is steel, not aluminum like the
G3RUH.  I used it on AO-40 for 24 GHz.  Let me know off-list if you want it.

73,
Jerry, K5OE

---- previous message ----
You probably have one of the K5GNA "BBQ" dishes. The G3RUH is a solid round
spun dish.

73, Drew

-----Original Message-----
>From: Bob Bruninga <bruninga at usna.edu>
>Sent: Jan 3, 2012 2:19 PM
>To: 'Andrew Glasbrenner' <glasbrenner at mindspring.com>, 'amsat-bb'
><amsat-bb at amsat.org>
>Subject: RE: [amsat-bb] Looking for a G3RUH dish
>
>> I'm looking for one of the 60cm G3RUH dishes
>
>Got one, (but not available).
>
>Questions:  I measured reflector grid separation as .88 inches which works
>out to be about 0.18 wavelength.  I always thought the grid had to be
>tighter than 0.1 inches to be an effective "surface".
>
>Maybe the difference with almost double the spacing is not that
significant?
>(especially for a steel one which would be quite heavy.
>
>Reason I am asking is that I also need another S band dish (at 70 MPH on
the
>roof of a tracking van) and we are thinking about building one by using an
>old solid 6' TVRO dish as a form and laying in copper wire and soldering it
>to copper straps.  With all that labor, I'd not want to get the spacing
>wrong.
>
>Bob, Wb4APR
>

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