Page 31 - EngineerIT April 2022

AMATEUR RADIO

The changing face of Amateur Radio

home construction

By Hans van de Groenendaal ZS6AKV

here was a time when radio amateurs had to design and
construct their own equipment, which resulted in interesting
Tdevelopments and some very original designs. The pages of
early radio magazines were full of circuits of receivers, transmitters and
construction ideas. Those were the days of large transformers, and the
magic of glowing radio valves were often more efficient as heaters than
amplifiers. The components that were not readily available were self-
made. The early pioneers were not called radio amateurs. It was only
after the commercial world realised the benefits of radio that, when
it came to spectrum, they referred to “the amateurs” and claimed
the long- and medium wave bands, moving the amateurs to higher
frequencies. Being pioneers, the amateurs soon showed the world that
on higher frequencies, one could communicate over long distances and QCX+: A feature-packed, high performance, single-band 5W CW transceiver
kit, with WSPR beacon and built-in alignment/test equipment. Available
connect continents. for 160, 80, 60, 40, 30, 20 or 17m bands. It has rotary encoder synthesised
I remember in my early teens building a foxhole radio, made tuning, VFO A/B/Split, Iambic keyer, CW decoder, and more...
famous by soldiers in Europe listening to news from the BBC’s medium
and long wave transmitters. It was a toilet paper core with 300 turns literally hundreds of projects for which software is available free of
of any scrap-enamelled copper wire wound on it, with taps every few charge. Check out https://www.dxzone.com/. A raspberry Pi and a
turns for tuning, a razor blade and a safety pin as a detector connected single dongle can be turned into a powerful radio receiver or a low
to earphones. Those were the days! power transmitter. There are various amplifier modules on the market
Innovation and the ever-increasing speed of new developments that can be added to increase the transmitter power.
did not pass amateur radio equipment by. Today, sophisticated state- Even with all the technology disrupters, amateur radio still
of-the-art designs of receivers, transmitters, amplifiers and peripheral remains a vibrant techno-pastime to carry out what the ITU in its
equipment are commercially produced and come at a heavy price. amateur service regulations calls self-training and experimentation.
The rapid development of smaller and smaller surface mount devices Amateur radio has truly embraced the digital world. It may take
and components, and the rapid demise of leaded components, have some time for older radio amateurs to embrace this, but the bonus is
made home construction for most people near impossible. There are that digitally inspired amateur radio is embracing the iGeneration and
still kits on the market supplied with pre-assembled surface mount this is great for the future of an engaging techno-past time. n
devices. A popular source of kits is QRP Labs (www.qrp-labs.com), the
brain child of Hans Summer G0UPL. The complexity of the QRP-Lab kits
ranges from kits for beginners to equipment for the very serious and
experienced constructor.
Many radio amateurs and indeed electronic hobbyists have packed
away their soldering irons and have moved to systems design, building
equipment by connecting and interfacing various pre-build modules
and software to create a receiver, transmitter or a transceiver. The
pioneering spirit is still there, it has just taken on a different format,
but as complex as the most sophisticated commercially available
equipment. A great example of this is a ground station to communicate
with amateur radio’s first geo-stationary satellite Qatar OSCAR 100
(OSCAR - Orbiting Satellite Carrying Amateur |Radio). The satellite
was built by members of AMSAT DL in Germany and is hosted by the
Qatar Amateur Radio Society on a commercial geo-stationary satellite.
A typical ground station is built up from various modules that are
interconnected and software controlled.
Many other home construction projects are based on various
versions of the Raspberry Pi and other small computers. There are

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