THE LATEST IN NETWORKING AND WIRELESS TECHNOLOGIES
■ BY LOUIS E. FRENZEL W5LEF
What it is, how to do it, and what to buy.
Listening to the radio has got to be one of the oldest electronic past times
there is. Not long after the first radios were put into operation in the early
1900s, there were enthusiasts who put together their own radios from junk
parts just to hear what was on and to experience the thrill of tuning in a
station from far away ... without wires. Once the vacuum tube came along,
radio really took off and stations sprung up around the world. Even with a
simple radio, you could hear local and far away stations. Today, there are still
many of us who like to do this. The activity is shortwave listening (SWL) and
it is both fun and a challenge.
58 April 2010
WHAT IS IT?
I was introduced to SWL in my early teens when my
father brought home an old Hallicrafters S38B radio he
used on board the oil tanker where he was the captain. I
strung out some old telephone cable for an antenna and
was amazed at what I heard. Foreign broadcasts, amateur
radio stations, and all sorts of other strange things. It was
fun and an eye opener. It got me interested in ham radio
and I managed to get my license in my mid teens. I never
tired of listening to whatever was on.
Another early project was my first crystal radio. I had
one of the early galena cat’s whisker detectors and wound
my coil on a cylindrical oatmeal box. I finally got it to
work with a long enough antenna, but could only hear
local AM stations. It was satisfying, though, to know one
could make a radio like this. Later, I built some single tube
radios that worked better than I could have imagined.
Even today with all the smart phones, digital TVs, and
sophisticated ham radio gear, I still find time to scan the
radio bands for interesting stations.
SWL is the process of listening to the shortwave
bands, generally in the range from 3 MHz to 30 MHz.
That includes in all the international broadcast
frequencies and the low end ham bands so there is lots
of stuff to listen to. While international broadcast stations
are the most popular targets, there are other sources like
marine, aircraft, military, CB radio, and the occasional