TCP-group 1991
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SS and AR -> proxim units
- To: tcp-group@ucsd.edu
- Subject: SS and AR -> proxim units
- From: Kevin J. Rowett <kevinr@suntan.tandem.com>
- Date: Thu, 3 Jan 91 10:35:09 PST
[...]
>been running various tests to see how well they function and the maximum range
>we can get with the 1 watt units. To date we have been able to get a range of
>2.3 mi by using yagi antennas.
>> don't have to be as sensitive as receivers for MANs or even WANS.
>> Those PROXIMs work to about -40dBm.
[...]
> Thanks for pointing this out. You are correct that the Proxim units were
>designed for the LAN environment. The units which I am now playing with work
>at -90 dBm.
> Proxim now realizes that they made a mistake in their product design. It
[...]
Humm.. Someone's calculator is broken.
Over your 2.3 mile test path, PL could be estimated at 104dB.
( 37 + 20 log distance + 20 log frequency ).
I understood the Yagi you used to have 18 dBi on one end
and 12 dBi on the other end. Add to this your stated power
output of 1 watt (30dBm) I get a total of 60 dBm ERP.
This leads to a input power of -44 dBm, which must be the
sensitivity of the units. You've used the free air as
a graduated (very fine ) step attenuator.
N6RCE