[amsat-bb] Outernet WiFI and Omni Mobile antenna?

[Robert Bruninga]

> I apologize for using the AMSAT-BB for an OUTERNET...
> When using Outernet's Wi-Fi ability, I am wondering
> what the effective range of that Wi-Fi may be?

I Quintupled the range of my Outernet Raspberry Pi from about 200' outside
to about 1000' outside by soldering on a 1.2" piece of wire as a 1/4 wave
vertical compared to the on-board-ceramic antenna...  This hotspot would
be able to cover the entire fleamarket at Dayton for example.

see:  http://aprs.org/outnet-hotspot.html

And then today, I played around with EZNEC to see if I could come up with
an Omni Vertical to be able to have an Outernet Receiver in my car able to
receive the Outernet signal no matter what direction the car was pointed.
I came up with this:

http://aprs.org/OUTNET/antennas/Colinear-100ohmsX.png

I haven't built it since it requires a hole in the middle of the roof, but
its an idea...  This omni is 17" tall and has a conical max gain of over 9
dBi at an elevation angle of 40 degrees that matches the elevation angle
of Inmarsat over the central latitude swath of the USA.  It was hard to
get the 40 degrees, but was easier at 45 degrees and higher just with
simple long monopoles, suitable for Southerners or Mexicans.  Just cutting
wire whip to the right length without even a phasing stub works at these
higher elevation angles (and lower latitudes).

Of course a helix woiuld be an easy to build antenna, but it needs to be
pointed at the Inmarsat satellite which is geostationary south of Texas.

For the overall ham radio ideas for this Global Outernet system, see:

http://aprs.org/outnet.html

Bob, WB4APR