On 22 Feb 2005 18:10:53 -0800, "Dave" wrote:
Thanks for the advise. However, I thought 1/4 wave antennas were more
isotropic than 'most' other antennas... (see link below)

http://www.astrosurf.com/lombry/Radio/dipole-height.gif

What am I missing?

Hi Dave,

Umm, those are lobes for a HORIZONTAL dipole --- wrong polarization,
wrong size. Cross polarized signals come with beaucoup loss.

Basically, all I'm trying to do is increase the sensitivity of my
handheld scanner for the 2m range.

If the balloon is overhead (or off of overhead by ±15°) you are 10dB
down at best, or sitting in a deep null (deaf city). To compare that
30° cone of silence: Hold your hand directly overhead, spread out
your fingers and thumb, the distance between little finger and thumb
tips spans 13 to 15 degrees (half that cone).

Is your balloon in that cone? Worst possible place for a short
vertical antenna to hear; and for a balloon with a short vertical, you
are in the worst place for it to shout down to you. This is a deadly
combination that puts your normal signal at -20dB (or worse).

A KW linear may overcome this sensitivity problem however.

73's
Richard Clark, KB7QHC