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cost comparisons



Al Lawler wrote:

If I had to summarize AO-40  cost distribution, I'd say that the
cost has moved from the desktop to the antenna mast, but it certainly
hasn't increased...  (And the antenna sizes for a GOOD receiving
setup are approaching what can be successfully loaded on a pair
of TV rotators...) 

Wayne replies:

I suspect that the combination of an 18-element 70cm CP yagi, 1 meter
crossboom, and a 54-element 13cm loop yagi is a SMALLER LOAD than the
average TV antenna.  It is entirely practical to use with cheap TV rotors.

A 13cm receiving setup consisting of a 3-foot dish (or loop yagi), preamp,
and surplus downconverter will COST LESS than the big yagi and preamp that
most people used to receive the 2m downlink from AO10 and AO13.  And that's
not counting the fact that you can get away with much cheaper rotors.

There seems to be nearly universal agreement that 2m is NOT a good band for
high-orbit satellites or earth stations.  Antennas are too big, spectrum is
limited, noise is high, and there is too much legal and illegal interference
beyond our control.

70cm seems to be the BEST uplink band for the foreseeable future since
transmitters are widely available, antenna size is reasonable, and cable
loss is tolerable.

I'm still not sure if 13 cm is the best downlink band.  Antennas are cheap,
small, and easy to steer with TV rotors.  Surplus downconverters are cheap.
Good preamps aren't really very expensive.  But the signal is absorbed by
trees, which is a problem for a lot of people.  Also, interference from
unlicensed wireless devices will be a growing problem over the next few
years.

Too band 23cm isn't a permissible downlink band.  It probably would have
been the great downlink band from the perspective of antenna size and tree
absorption.  Is 10 GHz less affected by trees than 2.4 GHz?

Wayne Estes W9AE
Mundelein, IL, USA

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