[aprssig] News from DCC (3) 10 mile 100 KBPS packet links for $10?
Tom Hayward
esarfl at gmail.com
Mon Sep 24 12:34:12 EDT 2012
On Mon, Sep 24, 2012 at 10:09 AM, Bill Vodall <wa7nwp at gmail.com> wrote:
>
> The wifi 'Ubiquity Bullets' or 'Mikrotik Chocolate Bars' are in the
> same price range - just apply power, antenna and ethernet. How to do
> "ham radio" with them is a bit more of a challenge..
>
> http://www.flyteccomputers.com/details.cfm?wid=248&wb=Bullet2HP
>
> http://www.wifi-stock.com/details/metal_5shpn.html
The Bullet is ok if you plan to connect an omni/vertical antenna, but
this is difficult to make work on 2.4 GHz due to noise. I've found
long range 2.4 GHz to be very dependent on noise immunity. The
NanoBridge and the AirGrid are self-contained with good noise
immunity.
http://www.ubnt.com/airmax#nanobridgem
I haven't tried to do it with AirOS 5, but the older Ubiquiti
equipment was very easy to tune down into the ham band and out of the
ISM band. I had a NanoStation centered on 2395 MHz with a 10 MHz
bandwidth (default 802.11g is 20 MHz). The way you do it is by
changing the country code to "Compliance Testing" in the firmware and
then setting the to channel -1. It's then necessary to follow ham
regulations by disabling encryption and identifying in some way. AirOS
5 handles country codes differently, so I suspect this is not possible
with their current line.
Versions of this hardware are available on 900 MHz, 2.4 GHz, 3 GHz, and 5 GHz.
W7YH has been working on a ham wifi network. I believe this article is
a bit out of date (I think the plan to use batman-adv was scraped due
to some shortcomings), but there's still a lot of interesting link
plots:
http://hamradio.wsu.edu/projects/wan
The big difference between W7YH's network and the HSMM-MESH project is
that W7YH is working on a Layer 2 mesh system so that DHCP can be used
to automatically assign IP addresses.
Tom KD7LXL
More information about the aprssig
mailing list