John at Spectrum International used to sell a strong 3 foot mesh dish for HRPT (WX).
Jeff K2SDR
-----Original Message----- From: Bob Bruninga Sent: Wednesday, January 04, 2012 5:54 PM To: 'K5OE' ; amsat-bb@amsat.org Subject: [amsat-bb] Re: Looking for a G3RUH dish
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@usna.edu Sent: Jan 3, 2012 2:19 PM To: 'Andrew Glasbrenner' glasbrenner@mindspring.com, 'amsat-bb' amsat-bb@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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_______________________________________________ Sent via AMSAT-BB@amsat.org. 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