The Stereogram
It’s a wintery Sunday evening in 1975. I’m nine years old, visiting my grandparents with my mum and dad as we do most Sundays.
Gran and Granddad lived in a small isolated “two up two down” cottage in the Peak District of the UK. There wasn’t much for me to do on a winter’s night as the grownups busied themselves talking about grownup things, but in the “best room” was an old 1960s style “stereogram”. This was essentially a piece of furniture that had two loudspeakers hidden in it, a record player for playing vinyl records at one side, and a box for storing the records at the other. Between the two ends, under the lid, was a radio. Unlike any of the radios we had at home, this one covered the shortwave bands.
A quick word about frequency bands: Nowadays, most radios have pretty advanced technology that enables them to deliver crystal clear sound without the listener having to know much about how they work. But back in the 1960s and 70s, you could tell (if you knew how) from the sound of a radio which of several different technologies it was using. One of the most important factors in this was the frequency band being used to carry the radio signal. Frequency here means the number of times per second that the radio waves wiggle up and down. For domestic radios, that number ranges from about two hundred thousand to a hundred million. That number doesn’t change the principles of how radios work, but does affect how radio waves travel from the transmitter to receiver. At the low end (200,000 times per second) the waves are large (like a kilometre long or more) and they hug the surface of the earth as they travel a few hundred miles before fading into nothing. At the high end (100,000,000) they are much shorter (a couple of metres long) and travel in straight lines and travel say 50 miles. But on the shortwave bands – where the wiggling happens between about 3,000,000 and 30,000,000 times a second and the waves are shorter than the kilometre long ones (hence “short wave”), they travel in straight lines but also bounce off a layer of atmosphere called the ionosphere. This means that the waves can fly up towards space, but then reflect back down and land hundreds or thousands of miles away. Where this gets quite magical though, is that the ionosphere also wiggles, which makes things a bit hit and miss!
Gran and granddad’s “best room” was almost never used. The only heating was a log fire, and that was only put on when the room was going to be used for a special occasion. It was cold, and the air had a slightly damp feel. But I sat there anyway, listening to the radio. The radio worked by using old style “valves” rather than transistors, which meant that it took a minute or two to “warm up” when you first switched it on before it started working. The valves literally had to warm up, as they produce heat when they work, and this meant that the radio smelled of warm wood and hardboard when it was working. That smell combined with the slightly damp & cold room air and the excitement of what I might hear that night.
I had read about the ionosphere in a book that mum had got from the library for me, and as I listened to radio announcers saying “This is Radio Canada International” or “This is Radio Sweden, Stockholm” I knew that the radio waves were bouncing off of the ionosphere to get from the huge radio antennas in another country to find me in my gran’s best room listening to their programmes. Unlike today’s radios, the signal would fade in and out. Sometimes it was strong and clear, and sometimes it would disappear into background noise. As it did, I imagined the ionosphere heaving like a sea in the sky and reflecting radio waves sometimes better and sometimes worse. It made me feel connected to physical nature, and it was also a bit spooky because the ionosphere was almost like a living and breathing thing out there in the dark.
Because of the way that the ionosphere changes with the time of day and the seasons of the year (it has a lot to do with where the sun is relative to the transmitter and receiver and how many sunspots are on the sun at the time), shortwave broadcast stations had to adapt their programme schedules carefully to ensure that they could reach their intended audiences. So they would publish schedules telling you when to listen and what frequency to tune in to. And the programmes would last only an hour or 30 minutes, and if you tuned in before or after that all you would hear was background noise or an entirely different radio station in an entirely different language, and you would never know what you had missed.
It was way before the internet, and the only way to get a programme schedule was to ask the station themselves for a copy (which required knowing their address, to write to them!) or look for highlights in specialist Shortwave Listening magazines (which were themselves pretty hard to come across in your local newsagent!). So there was an awful lot of detective work and random chance and making notes of what I had heard.
So I looked forward to sitting alone in the dark, in that cold best room, listening to programmes about coal production or whatever it was, coming from a far flung place. Occasionally I would hear a programme about shortwave listening and I would frantically scribble down frequencies and times like I was a code breaker gathering keys!
Electronics and Radio
When I was nine, I built myself my own radio receiver. The instructions for how to do it were in a Ladybird Book called “making a Transistor Radio”.
As I grew older, I learned more and more about how radios worked and eventually started designing my own circuits. I ended up going to university to study Electronic Engineering.
But always the feeling of sitting in gran’s best room would be the thing that had me hooked on straining my ears to hear weak signals scratching just above the background noise.
One way to become able to hear even weaker signals, or signals from further away, is to use better antennas. Making your own antennas is pretty cheap and easy if you know how, so as a teenager I was able to do loads of experimenting. I had spent hours as a young child reading and re-reading a book that dad had got for me, called “Out of Thin Air, a Guide to Aerial Theory, Design and Propagation”, so I was well prepared.
Most shortwave antennas are made from wire strung up in various shapes and lengths and connected together in certain ways. Wire was cheap (or free if I found an old electrical transformer or motor and took the wire out!). So I could experiment a lot.
When I did my degree, I really enjoyed the classes on electromagnetic theory because these explained how the antennas, that I had loved since I was young, worked. I ended up doing a PhD that was centred around how well antennas work when there are bits of metal and plastic close by (in the form of “radomes” that keep the weather off of radar antennas). All driven by my love of antennas, electromagnetics, and computer programming.
Ham Radio
Ham Radio, or amateur radio, allows people to transmit radio as well as receive it. It has a long history of experimentation and the value of the hobby is recognised by international treaties protecting special segments of radio frequencies called ham radio bands. These bands are dotted around the whole spectrum of radio frequencies. The most commonly used ones are on the shortwave part of the spectrum but there are bands where the waves wiggle at only a few thousand times a second and at the other extreme many thousands of millions.
All of the ham radio bands have their own “character” which influences the way that the radio waves travel, how much or how little this depends on sunspots, time of day, season and even plain old meteorological weather, and how big or small the antenna needs to be to be able to use them.
Generally speaking, if you want to transmit radio waves, you need an antenna that is a reasonable fraction of a wavelength long. Remember that some radio waves are kilometres or more long and you’ll see that this can pose a bit of a challenge! But antennas have many types of design and some antennas that are very small can do better than you might think. I find a lot of fun playing with these small antennas – not least because it means that I’ve been able to have a lot of fun with antennas that I’ve been able to construct entirely inside my house – where they are easy to get at and adjust whatever the weather is doing outside!
The shiny bit of metal bent into a loop in the picture below is a small antenna that I’ve just built. The black box contains an electrical circuit that allows it to be connected to my ham radio transmitter. The glowing screwdriver on top of it is entirely unnecessary; I put it there for fun because when I transmit through this antenna the radio waves, where the screwdriver is, are string enough to make it light up without it touching anything metal. And I find that spookily joyful (or joyfully spooky), just like when magnets move each other without touching.
And, I’ve used this antenna tonight to transmit radio waves that have been picked up – by someone who answered – in the USA. The radio waves in this case are 20 metres long, and this loop of metal is not even a metre across and is just resting on a set of drawers in my room!
“What do you talk about?”
One question I usually get asked when I mention ham radio is “What do you talk about?”. Sometimes this comes with a bit of puzzlement too if the person knows I’m autistic – because they assume that autistic people don’t like talking a lot & especially not to strangers! Or perhaps they know that autistic people hate talking on telephones (have a look at Autism and Phone Calls!) and wonder how ham radio is any different.
Well, there are a couple of ways why the way that we communicate on ham radio is absolutely fine for this autistic person.
- Firstly, it’s important to note that not all communication on ham radio is by voice. In fact, ham radio started out using only Morse Code, and it was quite an innovation to be able to hear the voice of the person at the other end. Morse Code is still used by radio hams, essentially for the fun of it. But there are also more modern ways of communicating that don’t require talking, and these use a computer to turn messages into sound that is then broadcast, received as sound at the other end, and then back into messages by another computer.
- Secondly, when voice is used, at least if you’re part of a crowd chasing weak signals from distant places, the exchange follows a formula. It’s basically “Hi, this is my station identifier, what’s yours?” “I’m hearing your signals strongly/OK/weakly – how are you hearing mine?” “Thanks & best wishes!”. It can get more involved than that but if radio conditions are unpredictable and signals are weak, that might be all that can be done.
So what do you do with the hobby now?
There are so many different aspects to the hobby that it’s hard to list them all. Some people are interested in talking, some are interested in technology. Some see it as a kind of sport, competing to see who can talk to the most people or most different countries in the shortest time. I like to design and test antennas, and then test them against the prevailing radio conditions to see how the perform.
It’s a hobby that’s been with me on and off since 1975 and doesn’t show any signs of going away …
Logbooks!
One of the things I love about the hobby is the way that we all collect information and keep logs of it. This was originally a condition of the transmitting radio license, but nowadays most radio hams do it voluntarily because it forms a pleasurable and valuable discipline. And as an autistic person who loves collecting and analysing data of all kinds – what’s not to love?
Now that we have the internet, we all put our logs online so that we can check contact details with each other. The latest entries in my online log are under the tab titled “Logbook” here: https://www.qrz.com/db/G1OJS and if you click on the tab labelled “biography” (or simply stay on that tab, because that’s where the link lands) you can see more details of what I get up to with the hobby and see a few more pictures, including one of what’s inside the black box above!
Alan By The Sea 
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