HearSat Frequently Asked Questions (FAQ)

2. What kind of antenna do I need?

OK, we are going to assume that if you have to ask this question you
are not an expert already. You are probably looking for an antenna that
will improve the reception you are getting with your indoor whip or
"rubber-ducky".

When you are an expert you will have bought a copy of the ARRL Antenna
Handbook and already be designing your own specialized antennas for
satellite work.

The simplest antenna to build which will dramatically improve satellite
reception (especially if you mount it outdoors; e.g. on your roof) is
the quarter wave ground plane. Here is how to build yours:

How To Build an Inexpensive Satellite Antenna
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The following instructions will enable you to build
a quarter-wave ground plane antenna with which you will
be able to receive satellite radio signals better than you
can with the "rubber-ducky' or telescopic whip antennas
usually supplied with scanners and other low cost receivers.
This antenna is tuned for the 2-meter ham band (144-148 MHz)
but will give very good results for other similar frequencies.

You will need:
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5 conductors, each 19 inches long. Stiff copper or steel wire,
or even coat hangers will do the job.

1 SO-239 chassis mount coax connector from Radio Shack or your
neighborhood electronics store (actually a female BNC connector
would be even better).

1 length (no more than 50 feet) of RG-58U coax cable. You
can also use RG-59 TV coax but the impedance will be 75 ohms
instead of 50 ohms. This will result in some loss of signal.

4 nuts, bolts and solder tags.

Construction:
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Step 1:
The SO-239 connector has four mounting holes for bolting it
to a chassis. Using the four nuts and bolts, mount the solder tags
on these holes.

Step 2:
Solder four of the pieces of wire to the four solder tags. The
four wires will spread out perpendicular to each other to form
a horizontal "ground plane". To improve performance, you can bend
these wires down at 45 degrees to the horizontal.

Note - If you are using steel conductors you may have difficulty
soldering directly to the tags. If so, bind the steel conductor to
the solder tag using copper wire and, using a high power soldering
iron, seal the joint with solder.

Step 3:
Solder the fourth wire to the central conductor tag of the SO-239
connector so that it projects vertically with respect to the other
wires.

Step 4:
Connect the RG-58U coax to the SO-239 connector and to your receiver,
and mount the antenna as high as possible - preferably outdoors.

Notes:
------
The ground plane antenna is a good general purpose omni-directional
antenna (i.e. receives equally from all directions), but it has low
gain for signals coming from directly overhead. You will find the
strongest signals will be heard when the satellite is between about
15 and 50 degrees above the horizon.