Once
bitten by the shortwave listening bug, you’ll never be satisfied until
you’ve done everything in your power, physically and financially, to be able
to hear everything there is on shortwave. And that’s saying something,
because there are dozens of monitoring niches for you to explore. Most SWLers
listen to a broad range of signals, but many specialize in certain types of
monitoring such as pirate radio broadcasters, numbers stations, utilities,
amateur radio stations, digital modes, QSL collecting, beacons, and more.
However,
to increase your chances of improved reception you may need to make some
additions to your listening post. Here are some things to consider adding: An
external antenna, a signal filter/processor, and a computer interface.
Antennas for All
Occasions
The
radio art is just one hundred years old and there are probably thousands of
antenna designs which have been used throughout the course of the century.
Over the years, though, a few have stood the tests of time, technology and
solar cycles. While there’s not a single antenna which can be truly called
the perfect antenna, there are a couple which have proven to be good
performers for certain bands. (See the recent series in MT's Antenna Topics
column for more.)
One
that I’ve had much success with as a ham and an SWLer is the Grove Tunerless
All Band antenna (see drawing). Designed by MT’s Bob Grove, this
antenna is an excellent receiving antenna for the entire high frequency (HF)
spectrum (1.8 MHz to 30 MHz). It’s based on numerous other successful HF
antennas and has all the qualities one should look for in a great external
antenna: 1) It can be easily built even by someone with no experience building
antennas. 2) It’s relatively inexpensive. 3) It’s a low noise antenna. 4)
It makes a great transmitting antenna for SWLers who later become amateur
radio operators because it will allow operating without the aid of an external
antenna tuner. Its biggest drawback is its size. At 134 feet overall, it may
not fit on many suburban lots.
Grove Tunerless All
Band antenna provides optimum listening across the HF spectrum (courtesy Grove
Enterprises)
While
this antenna works great for all HF bands, for the lower frequencies (AM band
and below) more directional and even quieter antennas are needed. That’s
where another old standard design comes in. The Beverage antenna was named for
its designer H. H. Beverage. It’s particularly useful for the lowest bands
(150 kHz to 1800 kHz) because it’s extremely low-noise and very directional.
This is important because the AM band tends to be very crowded. Random signals
from all over the country on any given AM frequency make it very hard to
single out just one. It also needn’t be higher than 10 or 12 feet in the
air. However, its biggest drawback is that it requires a vast amount of
property. Beverage antennas usually need to be at least one wavelength long
and at medium wave frequencies that’s huge – on the order of 500 to 1,000
feet long.
A
popular AM antenna which doesn't have the drawback of size is the old-time
“loop” antenna, which is a fairly small loop of wire or many strands of
wire which can be rotated in order to null or tune out signals on the
same frequency coming from different directions. While not as sensitive as the
Beverage, these are very effective AM antennas and take up very little space.
Signal Filters
and Processors
One
of the biggest improvements in shortwave radio reception in the last ten years
has been the introduction of digital signal processing (DSP). Radio
receivers have always had a certain amount of filtering and signal processing
built into the internal circuits, but outboard DSP filters can improve
virtually any radio’s reception. For casual shortwave listening there’s no
need for a DSP filter, but for serious DX listeners trying to dig out weak
signals on crowded bands a DSP is a real help.
There
are a number of filters and processors available on the market. Generally
speaking, the less expensive a signal processor is, the less it will probably
do. I advise you don’t pay more for a DSP than your radio. While a good DSP
will definitely improve your reception it can’t work miracles. Some
processors are simply audio filters which serve to accent certain frequencies
and “roll off” other frequencies in the audio in order to clarify what you
hear. These are marginally helpful in light interference.
If
you are trying to dig out nearly unlistenable signals from a crowded band,
you’ll need a tunable DSP such as the MFJ 784B (see full review in March
‘00 MT). With an incredible array of filter adjustments at your
fingertips, you can quickly tune out interfering signals by simply turning the
front panel knobs to the mode you’re trying to hear. By adjusting for lowest
noise and strongest signal you can tune Morse code (CW), radio teletype (RTTY),
weather facsimile (WEFAX), slow scan TV (SSTV), HF packet and voice at signal
levels you couldn’t otherwise copy. Expect to pay $250 for the MFJ-784B.
MFJ-784B
Tunable DSP Filter helps separate signals on crowded bands (courtesy MFJ
Enterprises)
Radio Computer Interfaces
To receive the digital modes mentioned you'll need another accessory:
the radio/computer modem. It's one of the most exciting things to happen in
short wave listening in a long time. When first introduced these products had
limited capabilities, were extremely expensive and quickly fell out of date
with the continued upgrading of microprocessor technology.
Today such devices as the Tigertronics BP-2M (see full review Dec. '99 MT)
are available and relatively inexpensive ($70). By merely attaching the
interface to your computer's COMM port and plugging the other end into your
radio's speaker jack the interface can decode many popular digital modes.
Software for such a device comes with the product. Additional software and
updates are available on the Web.
Tigertronics Modem Interface adds a
visual dimension to your radio listening (courtesy Tigertronics)
It's possible to "homebrew" your own interface or take
advantage of the capabilities your computer's on-board soundcard may have for
receiving digital modes, but be aware that results might not be as
satisfactory as with commercially produced interfaces. Still, no matter how
modest your computer or short wave radio is you can "see" the action
on the bands with fairly simple equipment. And, if you're looking for even
more esoteric mode reception you can find that too, but, be prepared to pay
$500 to $1,500 for the gear and software.
Finding Your
Niche in SWL
For
most people, starting out in shortwave listening is the same: you want to
listen to distant radio stations from foreign countries, and hear music and
voices from other lands. There’s a thrill in being able to receive a signal
from a radio station halfway around the world. But, like most, you won’t be
satisfied with just hearing the big international broadcasters; you’ll soon
find a passion for other aspects of the hobby. As you will soon discover,
proponents of every facet of medium wave (AM) and shortwave monitoring can be
nearly fanatical about their pursuits. So, here are some really interesting
places to start.
* Low Band DXing.
This is the area below the AM band where the antennas are strange, the band
conditions normally bad, and the listening targets are weak signals of esoteric
origin. You can follow the action in the “Basement Band” in Kevin Carey’s
monthly column Below 500 kHz in MT.
* AM Band DXing. New
FCC rules and a greater number of AM stations have turned this band into
nighttime audio chaos. Advances in receiver technology, signal processing and
antennas make it possible to listen to America any night of the year. Catch Doug
Smith’s American Bandscan in each issue of MT for tips and
latest news.
* Tropical Band DXing.
As you might imagine, atmospheric conditions in the tropics throughout much of
the year are terrible. That makes the AM band nearly useless for domestic local
broadcasting in many countries which lie between the tropical lines on the
globe. These areas use the frequencies between 2300-2400 kHz, 3200-3400 kHz and
4750-5060 kHz. In this hemisphere listen for Spanish language broadcasts. Use
the MT Shortwave Guide in the middle of this magazine for frequencies and
times.
* Pirate Broadcasting.
Eschewing government authorization, these unlicensed broadcasters cluster around
6955 kHz +/- 10 kHz using bogus IDs and playing an assortment of music and
scripted comedy. Catch them if you can. Their transmissions are often short,
funny parodies of the shortwave bands themselves. It’s insider radio humor at
its best. Read more about pirates in George Zeller’s Outer Limits in MT.
* Numbers Stations.
Relics of the height of the Cold War, these stations are said to be sending
coded messages to operatives in the field by way of these “spontaneous”
transmissions. Often a female voice in Spanish enunciating numbers in groups of
5, these messages come and go mysteriously. It’s been spook-filled fun for the
last 40 years.
* Utility or “Ute”
DXing. The world’s governments, official and clandestine, keep the airways
humming in between the traditional shortwave broadcast bands with streams of
military, diplomatic and general government radio traffic. You can also hear
South American drug smugglers en route, Coast Guard vessels trying to find them,
Russian language taxis, North Atlantic fishermen, and even Air Force One. Who
needs TV? Hugh Stegman’s column Utility World has a two page list each
month in MT of recent loggings.
* QSL Collecting. QSL
is ham Morse code short hand for “verification of transmission.” Most
shortwave broadcasters will send you a QSL card verifying reception of their
signal if you send them a detailed report of what you heard and when you heard
it. It’s not as easy as it sounds. Many small countries are strapped for funds
and may not send a QSL card unless you send a self-addressed return envelope
with International Reply Coupons (IRCs) enclosed. It can also take
weeks or months for a reply. Details on the art of QSLing are found in Gayle Van
Horn’s The QSL Report.
But Wait, There’s More!
Once
you get hooked in the shortwave listening hobby, you may never be able to leave.
There’s an entire group of people devoted to reclaiming old broadcast radio
sets. You’ll find famous old names like RCA and Zenith and famous forgotten
names like Stromberg-Carlson and Atwater-Kent. Great old radios play again from
every era of the broadcast industry from crystal sets to the first transistors
thanks to the ingenuity and efforts of the folks in this end of the hobby. (See MT's
Radio Restorations column.)
There
are people who study the atmosphere and the solar cycle to try to forecast DX
conditions in the next couple of days or weeks or at least try to explain why
band conditions are the way they are right now.
You
can hear amateur radio operators conversing, conducting nets, running contests,
or even aiding in public safety or search and rescue operations. (See the On
the Ham Bands column.) You can hear amateur radio satellites as they streak
across the sky 200 miles over your house. (Listen between 29.300 and 29.500 MHz,
but remember they’re only in range for 10 or 15 minutes.)
You
can tune into radio stations all across the HF spectrum and find Time Signal stations.
These are government-run automated transmitters which tell the time 24 hours a
day. It’s a good way to test your receiver and antenna’s capabilities. There
are also low power beacon stations transmitting 24/7 on specific frequencies
which help you know what bands are open to what areas of the world. A list of
time signal propagation beacons can be found at http://www.scn.org/IP/nwqrp/archives/misc/beacon.html.
Here
are three other sources for links to hundreds more AM and SW DX web sites and
dozens of topics on this subject:
http://www.dxing.com
http://www.dxzone.com
http://frn.net
You
may never have imagined the incredible variety of signals which are available to
you when you first bought your shortwave receiver. But, you do now!
