LONG WAVE LISTENING

Since I mentioned it in 
2023-06-03BBC_Long_Wave_Hasnt_Got_Much_longer.txt, I've been quite 
curious about whether or not it's possible to receive Long Wave 
radio transmissions from the UK or Europe here in Australia. The 
Wikipedia page links to a database of long-distance reception logs 
that confirms the distance isn't out of the question, but I can't 
find any mention online of someone in Australia actually picking up 
Long Wave transmissions from Europe (which, since the Russians 
ceased transmitting on Long Wave, seems to be the only place from 
which voice trasmissions are still done).

Then while reading through a very early Australian radio magazine 
from 1924 called The Radio Experimenter, I came across an excellent 
article on overseas transmitting stations, complete with some 
wonderful photos of massive antiquated transmitters. But more 
interestingly still, this was introduced by referencing how some 
readers would have already been listening to these stations using 
the long wave receiver design detailed in an earlier issue of the 
magazine!

It's copied for you over in the History Snippets section:
gopher://aussies.space/1/~freet/historysnip

So I've been doubting whether it's possible today, while it turns 
out people were tuning into Long Wave transmissions from the UK and 
USA back then, and back when the transmitters were less powerful 
than some current ones too. Of course there were far fewer sources 
of electrical noise back then, but out here in isolated countryside 
there aren't any of those nearby either.

Compared to receiving Short Wave transmissions, popular enough to 
have an abbreviation as SWL (Short Wave Listening) ham radio people 
don't seem interested in Long Wave Listening at all. There has been 
some interest in hams getting permission to transmit on bands feed 
up due to the discontinuation of LW services like aircraft 
navigational beacons, but nobody seems to care about long distance 
reception alone. Short Wave likely does provide much of the same 
content without so much interferrence, long wave being more 
suceptible over long distance to noise from lightning and other 
background sources, so maybe that's reasonable. Still, in a way I'm 
just curious because I've never seen a radio with a LW tuning range.

Eventually via an archived (as usual) website of one of the 
Australian Long Wave Tx hams, I did find this reference to picking 
up some European Long Wave transmissions in Australia, including 
the 198KHz BBC4 Long Wave service:
http://web.archive.org/web/20020725000744/http://www.zeta.org.au/~ollaneg/lf/otherlf.htm

One thing that he, and the 1920s 'experimenters' (who, before 
scheduled radio broadcasts began in Australia, didn't have many 
other radio signals to choose from), had in common was long 
aerials. In theory an ideal Long Wave aerial would be about 700m 
(or over 2,000ft) long, which is why the transmitting sites have 
incredibly high vertical masts (which still might not reach the 
ideal). Transmitter aerials also need to be vertical to avoid 
reflections off the earth, but at least this isn't a problem for 
receiving. Still it's clear that some serious compromise is 
required.

I'm thinking of taking advantage of an unused farm fence that runs 
near my house and has an (un)electrified wire suspended beside it. 
Books recommend a receiving aerial to be about 30ft in the air, vs 
about 3ft for the fence's electric wire, and they recommend using 
copper wire instead of galvanised steel, but it's long (albeit well 
short of an ideal length) and conductive, so it seems worth a try.

For the receiver I'm thinking of trying both low and high tech 
routes. For years I've been meaning to build a frequency 
up-converter for RTL-SDR TV tuner dongles so that I can pick up 
sub-VHF frequencies with them by effectively adding (mixing) the 
received frequency to the frequency of a crystal oscillator. Now I 
think I might finally get around to it.

Also, because Long Wave only requires nice and simple electronics, 
I found some pretty easy designs for transistorised Long Wave / 
Medium Wave (AM) receivers. Definitely a 'junk box' class project 
for someone like me, which is appropriate for something I'm 
building to pick up signals that will only be around for less than 
a year. Also without the tighter contruction requirements of HF 
circuits (including that up-converter). Funily enough I've never 
built a radio receiver before. I built a transmitter once from a 
kit, but receivers are so abundant for Medium Wave and I'm not so 
excited by building electronics that do exactly the same thing as 
something that I already have.

 - The Free Thinker.