52 January 2018
AREDN — The Amateur Radio Emergency Data
Network is built from re-programmed Wi-Fi routers and
souped-up antennas (hams can use a lot more power than
unlicensed Wi-Fi gear) to build ad hoc mesh networks over
fairly wide regions. The system acts just like the Internet
except for not being connected directly to the Internet.
Any data you can ship over a network, you can send via an
AREDN system. (It’s ham radio, so no commercial content
Along with these two examples, there are literally
dozens of digital modes and protocols. The D-STAR system
also has a worldwide network of linked repeater systems
and an Ethernet bridge mode to link point-to-point systems
at ISDN bit rates. “Hot spots” and systems based on the
Raspberry Pi are beginning to make inroads, as well. Jump
in! The wireless water’s fine!
In the January and September 2016 issues, the Ham’s
Wireless Workbench columns touched on several common
types of antennas and the feed lines you use to connect
them to radios. An antenna system is the combination of
an antenna, feed line, and associated installation hardware.
Working with antenna systems involves several basic steps:
Design — Assess what kind of communication is
required, the distances involved, and the resources you
have available to build the system.
Select — Determine the right type of antenna and feed
line for the bands to be used; the type of communication
link required; and the available mounting hardware and
means of feed line access.
Install — Mount, aim, and tune the antenna; run the
feed line; install the connectors; connect the antenna to
the radio; and confirm the system is working as intended.
You can see how working with an antenna system
exercises a very wide variety of technical skills and
equipment. Installing an antenna will use everything in your
tool kit from wrenches to crimping tools to sophisticated
antenna analyzers. Hams are encouraged to build their
own antennas, and are one of the only FCC licensed
services to have that flexibility. If you can machine,
mold, or 3D print, you can “roll your own” with excellent
I used to tell my electrical engineering lab students
trying to troubleshoot a circuit that, “If the power supply
ain’t happy, ain’t nobody happy!” This is especially true
for radio communications. Regardless of whether you are
talking about portable low power radios, mobile rigs in
vehicles, repeaters on a mountain top, or a home base
station, the power source must be reliable and robust.
Let’s start with the battery packs for a set of handheld
transceivers. In a typical disaster response situation, you’d
need to maintain the chargers and battery packs; keep
It’s a technical hobby, so acronyms,
abbreviations, and jargon abound:
AREDN — Amateur Radio Emergency Data
Network. An ad hoc mesh networking system using re-programmed Wi-Fi equipment on channels shared with
amateur radio in the 2. 4 and 5. 6 GHz bands.
D-STAR — A digital voice and data system for
amateur radio. D-STAR transceivers are manufactured
by Icom and Kenwood. A number of third-party
accessories and apps are available.
Hot-spot — A device providing a bridge between
a digital voice transceiver and a digital voice system
server on the Internet.
ISDN — Integrated Services Digital Network. A
digital telephone networking service for commercial
Packet radio — A digital communications mode
using the amateur adaption of the X. 25 computer
networking protocol based on data packets. Packet
radio is primarily used on the VHF bands.
PACTOR — A portmanteau (combination) of
“packet radio” and AMTOR, which is “amateur
teleprinting over radio.” There are four different levels
of the PACTOR digital communications mode used by
RMS — Radio Mail Server. A station that acts as a
gateway between amateur radio and the Internet in the
Winlink — A system for distributing email via
amateur radio that uses gateway stations and Internet-linked servers.
WINMOR — A combination of “Winlink” and
“messaging over radio.” The WINMOR digital
communications mode was developed for use with the
Winlink email system.
Frequency Band Abbreviations
HF — High Frequency ( 3–30 MHz)
VHF — Very High Frequency (30–300 MHz)
UHF — Ultra High Frequency (300 MHz– 3 GHz)
Microwave — 1 GHz and higher