If you use a SWR (standing wave rate) meter, as used by radio amateurs,
you can show that a properly functioning, and tuned,
Duckie is just marginally worse than a normal antenna,
but it is very much dependent on the surroundings (you, the air and
the ground) electrical propeties, and if you hold the transmitter,
or not. The conventional antennas seems to be less sensitive to their
surroundings.
The easy way to check a Duckie is of course to use an rx with
a drastically shortened antenna! First, test where the rx loses the signal
when using a normal tx antenna - then substitute for the duckie. If the
range changes a lot, you know what to expect :-)!
I have never noticed any major difference - but if the duckie isn't
electrically sound the difference will be very big, as with any faulty
connection to the antenna (that is what I've seen happening - the connection
between the antenna base and the transmitting circuits failing!)!
With my R/C controlled winch (with no turnback), where I have a used tx
antenna as reciever antenna, I have found that the range, with the rx
antenna collapsed is about 300 ft with either duckie or standard antenna,
while with it extended it is further than my line is (about 600 ft). Both
are greatly affected when someone walks between the transmitter's and the
rx's antenna, especially if they are close to the tx, a situation which easily
could happen when the aircraft you are flying is low and you are holding
the antenna sideways to improve the signal to the model. You still have
line of sight contact with the model, but the antenna's "line of sight"
might be hanpered by fellow RC pilots, callers, judges, whatever.
This is less of a problem with a Duckie as then the antenna is always in front
of you - if you have line of sight the duckie will, too!
Tord,
Sweden
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Tord S. Eriksson, Ovralidsg.25:5, S-422 47 Hisings Backa, Sweden
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