[amsat-bb] Re: Antenna build photos

Tony VK5ZAI hutch at electric-web.org
Fri Dec 28 21:08:19 PST 2007

G'day Andrew,
Photos look great but I would suggest to get the most from your helix 
you should use a larger reflector, it's generally 1 wavelength diam. is  
OK. This does create a much greater wind loading, especially on the 
lower Frq's ,  probably one reason why they haven't gained more 
popularity. If matched properly you should be able to get a 1:1 SWR
I have just upgraded my 2m helix (no photos available yet) The 10 turn 
helix was previously made of 3 mm hard drawn copper wire. I have just 
replaced the helix with  15 x 2 mm aluminum strap. This has improved the 
gain considerably, I won't quote figures because I don't believe i have 
test gear to accurately measure antenna gain.

See :- http://www.electric-web.org/tracking_antenna.htm
Also :- http://www.electric-web.org/2m_helix_antenna.htm

Regards Tony.  VK5ZAI

P.O.Box 470 Kingston SE 
South Australia  5275

National ARISS Co-ordinator
and Satellite ground Station.

Web Site :- 

Andrew Rich wrote:
> http://www.tech-software.net/antennae/index.html
> Updated photo gallery
> ----------------------------------------------------------------------------
> Andrew Rich VK4TEC
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