another minor rural range test

[James Cameron]

G'day,

Having been enthused by linux.conf.au, my wife and I set up some more
rural range tests of the B-Test-1 units.

- 2007-01-22 A, test from a high point on terrain, failed probably due
  to terrain obstruction or very high temperature,

- 2007-01-22 B, repeat test using 1.3km known-good path, to exclude
  specific units from failure of 2007-01-22 A, worked fine, extended to
  1.4km,

- 2007-01-23 A, repeat test using 1.3km known-good path, during midday
  sun, to exclude solar coverage from failure of 2007-01-22 A,

- 2007-01-23 B, test unit in full sun for an hour, monitoring signal and
  noise level, to exclude battery charge level and temperature from
  failure of 2007-01-22 A, logged ticket 800.

We've restored use of a fantastic diagnostic tool ... an ordinary AM
broadcast radio tuned to one of the emission frequency harmonics of the
laptop.  With experience, one can learn what the laptop is doing as a
result of coverage changes.  It can also be placed near the antennae to
hear the transmission pulses.  Sort of like an electronic stethoscope.

Detailed test reports:

http://quozl.linux.org.au/olpc/2007-01-22-A-radio-range-test.txt
http://quozl.linux.org.au/olpc/2007-01-22-B-radio-range-test.txt
http://quozl.linux.org.au/olpc/2007-01-23-radio-range-test.txt

Photographs:

http://quozl.linux.org.au/olpc/2007-01-24/images.html

Graph of signal and noise over temperature:

http://dev.laptop.org/ticket/800
http://dev.laptop.org/attachment/ticket/800/quozl-2-in-the-sun.png

-- 
James Cameron    mailto:quozl at us.netrek.org     http://quozl.netrek.org/