DU7AFT HOMEPAGE

Utility Monitoring

The word Utility is used in the communication world as a jargon for any radio
station on the shortwave band that is not for public use as entertainment
( as in broadcast radio stations ) or hobby ( as in amateur radio stations ).
So those portions of the shortwave radio bands that are not for broadcast
or amateur radio are allocated for this, so the name Utility bands.
Utility stations are harder to hear than broadcast, but they are way more fun
and interesting to listen to. You'll find all the world's militaries, aircraft, nautical
and embassies communications in the utility bands anytime of the day to give
a more true to life entertainment.

The picture above, shows my shortwave receiver Icom R-71A and it covers the HF
radio spectrum from 0 to 32 MHz in SSB, AM, FM and CW with other digital modes.
Aside from the voice signals you can hear from this radio receiver, there are a lot
of other signal that are transmitted all over the world in digital data formats.
If ever you've tuned a shortwave radio you've probably heard some weird noise ...
these strange noises are data signals which ranges from a simple morse code to
encrypted military signals. Some such as RTTY, WEFAX and HF radio FAX are easy to
decode and contain news, weather reports and other informations for aero and
nautical services.

How can I decode these signals?

Basically, you will need a shortwave receiver capable of receiving SSB signals
and a simple computer together with an interface to decode the signals. There are
a lot of computer programs now available for this purpose. I'm using Hamcom and
JVFax programs with the same interface to decode RTTY, Pactor and WeFAX without
any trouble. I have also a Kantronics KAM (enhanced) as a back up unit to decode also
same as the above signals. There are days when I would monitor 2 to 3 stations at
the same time using the interface and the KAM.

So, if you think this hobby is exciting !...give a try !. There are plain voice signals
to start with...like for example in my case, I 'm always tuned to 8.942 MHz USB for
the lively communications among Air Traffic Controllers and Airline Pilots for
South East Asia.

Here are some links that I found to be exceptionally helpful when trying to get
into Utility Monitoring:

I hope you'll enjoy the Utility World !

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