A few years back, I decided to get back into SWL. I
didn’t have a radio so I started to look around. I decided
to start with a kit. I found a couple in particular that I
liked. One was the Model 1054 from the Tennessee-based
ham equipment manufacturer Ten-Tec ( www.tentec.com).
This is truly a retro kit as it uses one of the oldest circuits
around: the regenerative detector.
A regenerative detector is basically an amplifier that
also oscillates at whatever frequency it is tuned to. The
idea is to tune the amplifier to a signal, then slowly
increase the positive feedback to it. This does two things.
It increases the gain of the amplifier and narrows the
bandwidth. The best setting is just below the point where
the circuit breaks into oscillation (wiping out any
The receiver uses an FET RF amplifier and a couple of
FETs in a regenerative oscillator detector. A bipolar stage
gives some additional amplification and an IC audio
power amplifier drives either a speaker or a headset. The
receiver uses a set of pushbutton switches to select a
frequency band over the 5. 9 to 16. 5 MHz range. Power is
provided by two nine volt batteries. It took me about two
hours to build. Figure 1 is a photo of my receiver.
The antenna was a 20 foot piece of #22 hookup wire.
After I connected the batteries and made the few
adjustments required, I got immediate results. My initial
tests were during the day, so I didn’t find a lot of stations.
That night, however, I was amazed at what I could hear.
You do have to play around with the tuning, regeneration,
and volume controls but it is a process easily learned. For
$39, it’s a great experience.
Another kit supplier is Ramsey Electronics
( www.ramseyelectronics.com). They have a shortwave kit
called the SR2. Other kit choices cover the two-meter ham
band, the FM radio band, or the weather band at 162
MHz. They also have an AM aircraft radio kit. Ramsey kits
are well done and I have built several of them.
If you decide you want to do more listening, I suggest
a compact shortwave radio like the Grundig G4000A in
Figure 2. It is an AM/FM/SW radio with built-in antenna
and LCD screen. The tuning is all digital. It covers all the
shortwave bands from 1.6 to 30 MHz, plus AM (530 to
1710 kHz) and FM (88 to 108 MHz). A built-in BFO (beat
frequency oscillator) lets you listen to single sideband
(SSB) voice and continuous wave (CW or code) signals.
Prices for such a sophisticated radio vary from about $90
to $200. Eton ( www.etoncorp.com) offers this radio and
they have a wide range of receivers.
C. Crane is another good choice for shortwave radios.
They make perhaps the best AM radio for DXing. The
CCRadio- 2 Titanium in Figure 3 is a hot AM radio but it
also covers FM, the 162 MHz weather frequencies, plus
the popular two-meter ham band. C. Crane also makes a
great new SW receiver shown in Figure 4. The shortwave
model is called the CCRadio-SW. It has full AM and FM
coverage, and adds three SW bands from 1.711 MHz to
■ FIGURE 1. The Ten-Tec 1054 regenerative
shortwave receiver kit.
29.99 MHz. Tuning is digital. Check out the details at
Two places to shop for SW radios are your local
RadioShack ( www.radioshack.com) and online at
Universal Radio ( www.universal-radio.com). RadioShack
handles the Eton and Grundig radios plus some others.
Universal Radio has a huge range of choices. The Icom IC-
R75-12 is one of the most popular models they sell. This
triple conversion superheterodyne covers SW and
frequencies up to 60 MHz (so the six-meter ham band is
included). This radio is for the serious SWLer and sells for
Software-Defined Radios (SDR) are just that — radios
that implement radio functions in software that runs on a
computer or embedded digital signal processor (DSP). The
basic idea of an SDR is that the incoming signal is
amplified, then digitized by an analog-to-digital converter
(ADC). The resulting stream of digital data representing
■ FIGURE 2. The Grundig G4000A portable AM/FM/SW radio.
April 2010 59