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BELOW 500 kHz
DXING THE BASEMENT BAND
Kevin Carey, WB2QMY
kevincarey@monitoringtimes.com
Allure of Longwave
Welcome to another edition of Below
500 kHz. I’m often asked why I focus
my work on the longwave band, and
if I ever get tired of sifting through beacons. I
know that I’m not alone in my pursuit, and this
seems to be a good time to explore why we do
what we do!
First off, I’d like to say that longwave is not
all I do, and that chasing beacons is not all I do
when I am on longwave. I can be found exploring
just about any band or mode below 148 MHz, and
I even have a special affinity for a VHF band: 6
meters. However, longwave does hold an intrigue
that is hard to find elsewhere in the radio spectrum,
and I do spend much of my time there.
This month, we’ll review what draws many
of us to longwave – in part to share the mystique
to newcomers, but also to “jumpstart” veteran
listeners on this amazing part of the spectrum.
Here are the best reasons I can think of to include
longwave in your listening menu…
❖ New Ham Band Coming
Sometime in 2013, we expect formal approval
of a U.S. ham band from 472-479 kHz, resulting
from recent WRC-12 proceedings. This band was
a long time in coming, and now is an excellent
time to learn more about longwave propagation
and behavior. When approval is granted, you’ll be
in a better position to take advantage of the new
signals on the band, whether you are a ham or a
DX-chasing listener.
❖ Variety of Signals
I’ve said it before and I’ll say it again: Where
else in the radio spectrum can you hear so many
different types of signals in the space of just
500 kHz? On longwave, you can expect to hear
Natural Radio, Military signals, Time Stations,
Broadcasters, Beacons, and Experimenters – all
in this relatively narrow slice of spectrum. You
simply cannot become bored!
❖ Beacons: The Ideal DX
Target
If you were to design the perfect DX station
to listen for, what features would it have? How
about these for starters: 24-hour year-round operation,
near omni-directional transmission pattern,
constant and repetitive IDs (in CW mode, to help
cut through noise), and published location/operator
data. Guess what? Longwave beacons have
all of these traits, making them a perfect DXing
target.
❖ Propagation Stability
Take a listen sometime below 100 kHz,
and what do you hear? For the most part, this
is the land of military RTTY, time stations, and
other utilities that use longwave for its reliability
around the clock. How else would I hear Jim
Creek, WA (NLK/24.8 kHz) in broad daylight
near Rochester, NY, and hear the same station
at night with virtually the same signal strength?
When the signal positively must get through,
day or night, longwave rules. Even higher up
the band, stable propagation is a hallmark of
longwave operation, although skip does begin
to play a significant role above 100 kHz.
❖ Not Everyone Can
Tune It
Getting on longwave used to be quite a
challenge, because not many receivers available
to U.S. listeners covered the band. Until
the mid-1980s, you generally had two choices:
Buy surplus military gear, or build up an outboard
receive converter that would “move” the
longwave band to a range your receiver could
tune. Today, things are easier with the advent
of wide-range receivers covering down to at
least 100 kHz. Still, longwave capability is by
no means universal, and a suitable antenna is
required if you expect to hear much.
❖ Historical Significance
Some of the earliest work in radio communications
took place on longwave. In fact,
at one time it was believed that the longer the
wavelength the longer the communication range.
The shortwaves soon took over for most long
haul work, but the unique behavior of longwave
still makes it ideal for radio navigation, military
and other specialized users. In fact, it is being
“rediscovered” today as a fertile ground for low
power experimentation and homebrew construction.
❖ Underdog Status
To borrow a theme from a well-known
country song, some of us were “longwave” before
longwave was cool. As one example, I recall
former MT columnist Uncle Skip telling me of a
chance encounter he had with an old timer who
was chasing beacons on LF long before it was
a popular pursuit.
As I recall the story, Skip had stopped to
check out some discarded electronic “junque”
at the curb in front of this fellow’s house. As
he sifted through the goodies, he could hear the
repetitive sounds of Morse Code coming from
inside the home. He introduced himself to the
occupant and was invited inside to see the shack.
There, he noticed lists and lists of beacons this
fellow had heard. Apparently, he pursued the
activity with little or no knowledge that others
chased beacons on a regular basis. He was just
doing it to satisfy his own curiosity about these
stations.
That’s the kind of spirit I see even today
in longwave, regardless of the particular area
of interest. The “basement band” may not be for
everyone, but it has a fiercely loyal following
among those looking to explore the unusual and
the intriguing!
❖ Forgiving Circuitry
It is well known that things get trickier,
from a design standpoint, the higher you go in
frequency. In microwave, for example, even the
length of a trace on a circuit board can drastically
affect the operation of a circuit. No such
formalities exist in longwave radio. Component
leads can be feet long and still work just fine.
Audio transistors are sometimes used for RF
applications, and breadboard or perfboard construction
is perfectly acceptable. Does surface
mount construction have you down? Plug in your
soldering iron and try longwave!
❖ Mailbag & Loggings
I was pleased to hear recently from Larry
Shaunce, WDØAKX (MN), who writes: “Saw
your mention of the Sony 2010 as being a trusty
radio and I have to agree with you – it is one great
radio. Very reliable and the performance is just
hard to beat. I must admit, I have not tried any
of the more modern portable radios, but I use
my 2010 on a daily basis and it has passed the
test of time and still works like new. If anyone
is looking for a used radio and can find one of
these at a reasonable cost, don’t pass it up!
“I use it when I am out of the shack in other
rooms or outside under the shade tree on a sunny
Sunday afternoon. It also sits by the bed at night
for some late night tuning before I get to sleep,
and the timer on it works great for this use, as I
can fall asleep listening to something and it will
shut down automatically after 1 hour, usually
about right for it to soothe me to sleep.”
Hello Larry, and thanks for writing to Below
500 kHz. About the only trouble I’ve ever had
with my Sony 2010 was with the battery contacts
coming loose and giving me an error code on
60 MONITORING TIMES August 2012