Added to the growing list of amateur achievements
at VLF
http://abelian.org/vlf/amateur-radio/
It has been a very successful season so far. I hope this
encourages more people to have a go at VLF, we need more
transmitters and receivers.
Perhaps the perception is that it is difficult? Surely not.
Don't believe all those stories you hear about how hard it is
to radiate, or how difficult it is to find a location to
receive from!
Let's see -
- Low cost. You don't need expensive SDRs or test equipment.
Your PC soundcard is signal generator, spectrum analyser,
and SDR, all in one. Transmitter is just an audio amplifier,
even a low quality one. The most expensive thing you'll buy
is a load of wire for a loading coil.
- GPS timing? £18 quid for a NEO-7 module and you know your
frequency to the micro Hertz. Buy two, you'll use them!
- Easy to build. Just audio frequency signals, nothing critical
about layout. VLF is great for the homebrew enthusiast.
- You don't need a huge ERP. 10uW and you're on the air. Your
LF antenna will probably do better than you think at VLF.
- UK Notice of Variation? No problem, a simple application form,
and if enough apply, maybe the regulators will make that easier.
- Where else can you operate at the cutting edge with such
simple equipment?
In case you thing my location here is specially good, it certainly
isn't. The mains here at the top of the Calder Valley is very
rough, terrible sidebands. All the properties around here get
their power by overhead lines at 12kV and one of the two 33kV
lines feeding Todmorden is only a km away. The nearest 12kV
line is just 120m from the E-field antenna. 140mV RMS of 50Hz
on the E-field probe and a lot of harmonics. Reception here is
bad! You can probably do better in the suburbs.
How many times per century does amateur radio find a green field
to explore? Not just a new band but a whole new frequency range.
Don't miss out on this one!
--
Paul Nicholson
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