[amsat-bb] Re: Dish surface 'flatness'
domenico.i8cvs at tin.it
Sun Jul 27 12:25:39 PDT 2008
----- Original Message -----
From: "Peter Ellis" <vk1kep at gmail.com>
To: <amsat-bb at amsat.org>
Sent: Saturday, July 26, 2008 12:00 AM
Subject: [amsat-bb] Dish surface 'flatness'
> I am now the proud owner of a very 'second-hand' 3m mesh-covered
> skeleton dish.
> The mesh covering is metaphorical, rather than actual. I watched the
> dish on its back while as a group of small children rolled the dish back
> and forth and trampled holes in the mesh. That's the reason I was able
> to ask for it. "Please take it away," was the manager's reply to my query.
> Now, I need to re-mesh the dish, but I need to decide what 'flatness'
> ('true-ness') the surface should be. There has to be a formula, that
> encompasses things like: frequency of operation, curvature or focus
> distance, etc.
> I've done some looking online, but can't find it readily.
> Suggestions, and discussion, please?
> Please note: If you're going to also make product, brand name, or
> supplier suggestions, then be generic as suppliers and products in VK
> (Australia) will differ from where most list members will be sited.
> With thanks,
Hi Peter, VK1KEP
To answere your question I have sent to you in two separate email the
TECHNICAL REPORT # 5 of the Crawford Hill VHF Club - W2NFA
with the following subject:
"A PARABOLOIDAL REFLECTOR ANTENNA FOR 1296 MHz"
This paper covers the following matter :
Basic Designe Considerations
The Parabolic Reflector - Error Tolerances
The above article is currently used by all EME'rs and was written with
the contribution of many authors of the Crawford Hill VHF Club - W2NFA
The article is 10 pages long and it was necessary to divide it into two
zipped files each about 2 MB long
If some other people is interested on it pleas let me know
Best 73" de
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