[MLB-WIRELESS] New world record for wifi link (125 Miles).
dwsmith at bigpond.net.au
Wed Aug 3 16:47:06 EST 2005
Horizontal polarisation has been shown to be better over long distances.
All the amateur weak-signal microwave ops use H-pol.
In discussions with Tony this morning, I did some calcs of what would be
required for a legal linkup over the path from Mt Buffalo to Camels
Hump. Assuming that a preamp (e.g. Longreach 2.5dB NF) is in line, the
Rx noise floor is about -98dBm in a 20MHz bandwidth. Using a 22dBi dish
and allowing for 2dB of feedline loss, there's a link there using legal
power (+36dBm) - although the 5dB margin is not a lot.
It could almost be done with the large Hills gridpacks, although you'd
be betting on the advertised gain matching actual - has anyone measured
them? Perhaps 1.5m solid dishes might be better. Or a 1.8m mesh
satellite dish which could possibly be assembled in-situ.
I've never been to either, but I'm not sure that either Camels Hump or
the peak of Buffalo (The Hump?) are accessible directly by car. If not,
it means that all of this would need to be lugged up to the sites.
I have a 2.4GHz portable SSB setup that might be handy for setting up
the link. Mike Borthwick also has one (G'day Mike ;-))
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