Re: [amsat-bb] Helix feed

[Bill Howell <bhowell@xxxxxxxxxxxxxxx>]

n6paa wrote:

>Just so I get this right the first time, I've wound a helix and I'm 
>ready to solder it to a Type N feedthru.  Which end do I solder. 
>This will be for RHCP to receive AO40. From the solder end, should 
>the helix winding be clockwise toward the dish? Thanks, ron n6paa




Quoting from a G3RUH article (ftp.amsat.org/amsat/articles/g3ruh/a116.zip) :

=====================================
Helix
-----
This is 3.3 mm diameter copper wire.  In fact it's the solid inner stripped
out of a length of H100 coax (similar to Belden 9913).  You need about 1/2
metre.  Wind it all, about four turns, around a 40mm diameter former.  I
found a socket in my car tool kit that was perfect.  It will spring out
slightly after winding.  Wind it left handed, that is to say in the
opposite sense to a conventional screw thread.  As you look at it from one
end, it will recede anti-clockwise.
=====================================

It doesn't matter which "end" of the helix you solder, as long as 
it's wound in the direction described above.



-- 

Bill Howell
University of Texas at Austin
College of Fine Arts
Office of Computing Technologies
N5ALO  Amsat 32459  QRP-L 415
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