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Re: Iridium



One thing you may be overlooking in comparing the LEO hamsats with the
Iridium system is that the Iridium handsets receive commands from the
satellite
and will not transmit unless the system assigns them a clear channel and
gives
a go ahead to transmit. If all channels are busy then the Iridium user
will have
to wait until the system can provide a clear channel. There is also
active feedback
to control the users transmitter power to use the minimium amount
necessary.
This is quite unlike the system for the hamsats, where anybody and
everybody
can transmit wherever and whenever they want to and handheld HT's
compete
with fixed stations running large antennas and high power. Yes it is
possible to
communicate with a few watts through a LEO satellite with a hand held
radio,
but comparing Iridium or some other commercial system to ham radio is
like
comparing apples and oranges.

Dan Schultz N8FGV


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