[ACARS] The Benefits of a Balanced Antenna

[acars@mailman.qth.net]

Hi all,
a vertical dipole as well as a ground plane antenna (1/4 lambda) are =
good air band antennas mainly for two reasons:
- They are easy to construct
- They are easy to install outdoors

But generally they are the most basic/simple of all practical antenna =
designs, providing only a marginal gain compared to the ideal isotropic =
antenna. In airband monitoring the gain may not be *that* important, =
thanks to the FLs of our "targets"=20
But you can see the difference between, say a 5/8 lambda vertical and a =
1/4 lambda antennas. This difference is an improved ACARS hit rate and =
more A/Cs in your log.
Other good receiving antennas for airband are e.g., a J-Pole and a 1/2 =
wave vertical. This latter one requires a tuning section in the antenna =
(for 50Ohm coax) but it does not require any ground plane but just the =
stick. The J-Pole needs a tuning section as well, but it is very simple =
to make. You can find guidelines e.g., from the web.

As a conclusion, I have been using a tuned 1/4 wave GP with good =
results, and I have used even a 25-1300MHz discone with good enough =
results, but still there are much better antennas available and they are =
neither that expensive nor difficult to make.

With Regards,
Sami
OH6MLW