From: James Brown (jim_at_seti.net)
Date: Sat Feb 05 2005 - 07:07:09 PST
Thanks for the information Ed. I am glad your reminded me about the stiffness needed on the arm. I would have been tempted to make a long arm so that I could use less weight but I can see that would be a mistake.
Stay Tuned........ Jim
www.SETI.Net
Jim_at_SETI.Net
Argus station DM12jw
a BRIGHT
----- Original Message -----
From: Edward R. Cole
To: James Brown ; SETI League Argus ; SETI League Public
Sent: Saturday, February 05, 2005 12:17 AM
Subject: Re: Argus: Counterweight Idea Needed
Jim,
Sorry I think I misinterpreted your question.
If you are looking for mechanical designs. I have seen some amateurs use two parallel poles with dumb-bell weights slid so you can sadjust the balance. I another the ham used metal bucket fille diwth concrete.
My 2.5m dish is constructed with a square steel channel back frame so the simple solution was to drill and bolt some angle iron to hold concrete blocks which I secured with rope...crude but functional. The antenna actually has several adjustable counterweights but I unbalanced it when I removed the ku-band transceiver box which weighed about 40-lbs (it was worth $500 on the surplus market).
Whatever you decide on be sure that the counterweight structure is stiff and will not flex, otherwise the dish will bounce all over in a wind..possibly even set up a mechanical oscillation in some conditions.
Hope that is some help.
Ed
At 05:18 PM 2/4/2005 -0800, James Brown wrote:
My SETI antenna cannot lift it's self anymore (old motors, worn bearings etc.) and I need to add a counterweight to it. Does anyone have some experience with a counterweight on a large antenna (12')? How is it attached? How long is the arm? How much weight?
Thanks......... Jim
www.SETI.Net
Jim_at_SETI.Net
Argus station DM12jw
a BRIGHT
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