[amsat-bb] Re: ISS, 9:10 UTC PASS, rubber duck

[Gordon J. C. Pearce MM3YEQ]

On Thu, 2008-10-16 at 03:16 -0700, MM wrote:
> 
> The gain of a stock rubber duck antenna is usually minus 12 to minus 9 dBd gain.  The average car 1/2 wave dipole is Zero dBd gain.
> 
> More gain, better results.

I had a thumping signal yesterday with my homebrew J-pole.  Nothing
more.  I thought I might have used the Yagi, but that would probably
have only been worthwhile for catching the very ends of the pass.  As it
was, with my antenna about 12' off the ground in a suburban back garden
with trees and buildings around, I was getting full quieting at 15
degrees above the horizon!

http://www.gjcp.net/~gordonjcp/dualbandjpole.pdf

Here's a copy of WB6IQN's dual-band design (mirrored because I don't
want to cane the author's bandwidth).  I built the single-band version,
and it tuned up perfectly at 144.9MHz when built as described - I've now
built three, one on a pole in my back garden, one that I gave to a
friend to listen to the local repeater with (along with an old Icom
IC-22A - must ask him if it's got a 145.8 crystal!) and one to stuff
into my laptop bag and take to work.  You'd actually have to try to get
it wrong.

HTH,
  Gordon