A shortwave radio

Posted on May 2nd, 2016 in Opinion by Julian Edgar

It seems that about every 10 years or so I get excited about radios. No, not radios that can receive only AM and FM, but radios that can hear broadcast signals from all around the world.

They’re called shortwave radios.

In days gone past, shortwave radio stations were the main ways in which governments attempted to spread their gospel: Voice of America, Radio Australia, and so on. These days, streaming on the Web has replaced the need to listen to these broadcast stations – but there are still literally hundreds of stations on these frequencies.

This time I got excited when I saw how prices have come down for really exceptional radios that can work on these frequencies. Specifically, I bought a Tecsun PL-880, a radio with excellent reviews that can receive all the shortwave bands, in addition to being a very good (ie long distance) AM and FM receiver.

I can remember when a radio of this calibre would have cost around AUD$500: mine cost just over AUD$200, including delivery.

So what can it do? Well, there’re too much to cover here but the radio has 3500 station location memories, signal strength and signal/noise ratio meters, excellent sound quality and very good sensitivity.

It also has a built-in whip aerial, but as has always been the case for shortwave reception, better results are achieved by using an external aerial. Which is where this column comes in – yesterday, I spent most of the day putting up that aerial.

Antenna theory is complex – what with resonant modes for different frequencies and so on – but the simplest approach is to just put up a long wire, positioned as high as possible. I live on a few acres on the edge of a little country town, so there is room to put up a big aerial. Easing the process, there are also two tall gum trees on the block, located about 50 metres apart.

My tree-climbing days are past (especially when one of the trees drops boughs occasionally!), but I figured it would be easy enough to get a rope up into the trees from which the aerial could be strung. I ended up using a bow and arrow, the arrow weighted with sand (and then a bolt). A light line was shot upwards and over a tree branch, then this was used to haul up a heavier nylon rope.

At one tree, the nylon rope connected to an insulator I made from an offcut of high density polyurethane.

At the other tree, I hauled up a pulley through which another rope was passed. The rope holding the pulley was tied off. The rope running through the pulley connected to the insulator (and so aerial) at one end, and to a suspended weight at the other.  This weight keeps the aerial taught, even with the tree boughs moving in the wind.

Said quickly it all sounds easy, but it was actually quite a job to get the ends of the aerial positioned in the trees. (And, even then, they’re nowhere near as high as I’d like.) The end result is an aerial just over 50 metres long that is 6-7 metres in the air.

The aerial connects to a copper feed that in turn connects to a coaxial cable, which in turn plugs into the PL-880’s aerial socket. A ground connection is provided by an earth stake.

And does it work? Yes! Night time is best for receiving shortwave signals, and last night I reckon I could hear at least 100 stations.

But were they interesting? Well, not as much as they once were!

These days, with the rise of China in this part of the world, many stations are transmitting in Chinese. In fact, last night I think perhaps only one-fifth of stations I could hear were in English.

It still gives me a thrill though, listening to other countries on a radio.

(And, incidentally, the PL-880 is so effective that, using only its inbuilt aerial, on the AM domestic broadcast band you can hear at night a station on nearly every frequency – pretty good in Australia.)

No it’s not for everyone, but the idea you can hear the other side of the world using just a long piece of wire and a portable radio remains to me a thrilling idea. Yes, even with the Web.

Comments are closed.