|
|
A
Potted History
By
Stuart Finnis
I'm interested in many things but for a
mostly Tech based
website I thought it fitting to focus this potted history on my love
of
electronics over the years.
This story is actually quite typical among engineers. I can't remember
exactly when I first became interested in electronics, but I do
remember a
pivotal moment that put me on the path. I must have just been
approaching my teens when I came across a book called 'Build your own
Crystal Set'
in my local Woolworths in Chatham. I hadn't even heard of a Crystal
Set before, let alone
built one. Up until now I'd loved playing around with bulbs, batteries
and
motors, but this was different, and had to be done. My first attempt
was hit and miss because I hadn't a clue what a variable capacitor was,
so goodness knows what I used instead, but when I connected up my bed
springs as an aerial and a central heating pipe as the earth, things
started to happen. I can't explain the excitement I felt when I heard
for the first time, voices coming out of the little earpiece.
From that moment on, I was hooked by the electronics bug that would
stay with me throughout my life
 Probably the most important book in my life and one of the designs it featured After
that first crystal set and it's much improved offspring, came
amplifiers. Now I could listen through a loudspeaker instead of an
earpiece, which I invariably found wrapped around my neck when I woke
up in the morning. The thing is though, I was learning, and the
learning was effortless because it was fun. I remember building
a super regenerative receiver. These were great because you could get lots of
sensitivity and selectivity, and this opened up for me the world of
short wave radio. To hear stations from around the world was brilliant,
but I needed more performance. That's when, still in my teens, I built
my first superhet
receiver. It was a design by R.A.Penfold which was featured in Radio
& Electronics Constructor magazine. I even wrote to the author with
a technical
question about the circuit and was thrilled when I received a
personally signed reply. In parallel to my love of radio was my love of
audio. They kind of go hand in hand. The simple class A amplifiers I'd
built for my early radios and the push pull circuits using OC71
transistors were my 'Audio Education' and the stepping stones towards
the more powerful HiFi amplifiers that were yet to come
On leaving school I started a television engineering apprenticeship with Radio Rentals (sadly no longer around in the UK). They were a part of Thorn EMI and rented, serviced and repaired televisions and video recorders. Televisions were new to me but hey, they were radios and had amplifiers in them so how hard could they be! I studied electronics (City & Guilds 224) for three and a half years at Southgate Technical College in north London and also attended one of Thorn's excellent technical training schools in Plumstead. Living away from home during these periods was good for me. It was new, exiting and scary, but I remember those days fondly. So Radio Rentals took me on permanently and it was at a time when the first VHS recorders were starting to appear. As the new boy I was heavily involved with these because the 'old school' television engineers were terrified of this new fangled technology. VHS is now of course very old technology, but it was good at the time. Working in an electronics environment and having it as a hobby as well was great. I had access to lots of scrap circuit boards that I could strip down for parts for my projects and some TVs still had wooden cabinets that could be sawn up to make enclosures for my stereo amplifiers. I learnt a lot during those years and built tons of stuff  A valve black and white Thorn 1500 TV converted to teletext I
still had an interest in radio and was not satisfied with just
listening. I wanted to get in on the action and transmit as well. So
while I was studying at college, I was also studying for the radio
amateurs exam. I passed this and obtained a class B licence. My
callsign was G8ZTE. This limited my transmissions to VHF and above but
it
was still great fun using my Icom IC2E handheld 2 metre
transceiver. I joined a local radio club called the MARTS
(Medway Amateur
Receiving & Transmitting Society)
and made lots of friends there.
I
went on to learn morse code and took the morse test at North Foreland
lighthouse. Passing this allowed me to obtain a full class A radio
licence and my callsign became G4YJO
 "CQ CQ G4YJO" Having
access to so many radio bands now gave me the urge to build my own
transmitter. My favourite band as a listener was 160 metres AM. Hearing
all the local 'old boys' chatting away on their Sunday morning
'Frankly Speaking Net' was a delight and it wasn't long before I
joined them, though I think they were just tolerating the young
'transistorised' upstart. I was in my early twenties and to me they
seemed about a hundred! Us youngsters (Myself G4YJO, Peter G4UJG
&
Tony G0PZX) started our own Sunday evening net called 'The Doom and
Gloom Net' where discussions included the taboo subjects of (according to
the
licence terms anyway) politics and religion. We chatted away for
hours on end and it was thoroughly enjoyable
 Simple AM Transmitter There
was more to radio than just talking though. Radio hams had adopted a
system called RTTY (Radioteletype) which in the
old days was used to
send telex messages around the world. When I think about it now, it was
an early form of email. The real enthusiasts used
ex commercial mechanical teleprinters but I didn't have room for all of that, so instead I used a well modified Sinclair
ZX81. At the time I
didn't like
computers at all but it was the home made part called
the terminal unit that I was more interested in. This was the bit that
converted the data stream into
sound and vice versa, so that information could be sent as audio over
the air via the microphone socket
 ST5 Terminal Unit It
was very exciting back in the 80's seeing text scrolling up a TV
screen as someone far away was typing, but the ZX81 was notorious
for crashing and would regularly do so whilst in the middle
of a conversation!
 The Radio Shack Radio
and electronics construction slowed down when I bought my first
house. Other things now took priority and I didn't have the luxury of
unlimited time anymore. I kept my interest but couldn't build as often as I wanted to. My work bench was now the
kitchen table on which I remember knocking up various projects including a headphone amplifier and
yet another radio. Things were
happening in my life unrelated to electronics, which was good because I
didn't want to become set in my ways and be found as an 'old boy'
slumped dead over a radio transmitter holding a
microphone!
 Stereo Headphone Amp
AM Superhet Radio
What
happened next as regards hobbies was a surprise to me. My friend Neil gave me
his old computer. Up to that point I'd not had much interest in
computers and thought they were incredibly boring, but now for
some reason I was ready to bite the bullet and have a go. And you know
what? I became hooked! I spent hours and hours and hours playing with
my new toy. I didn't realise just how much I was teaching myself
because it was so much fun. I kept seeing new possibilities, and
wanting to achieve those possibilities became the driving force that
made learning so effortless. And soon I was up to speed.
It wasn't long though before I wanted
to build my own PC. To my mind they don't really count as an
electronics
construction project as all the parts are ready made, so it's more
assembling than actually constructing. If I had soldered all
the components onto the motherboard then yes, I could say I built it,
but that's not really feasible for the home constructor. Assembling a
PC can still be very enjoyable though. I think what got me with computers was that I could see they were not
just one thing, they were whatever I wanted them to be, and one of the
things I wanted mine to be was a radio. I had grown up with a great
love of talk radio, I guess from listening to short wave broadcasts on
my home made receivers. I also enjoyed the late night phone ins on LBC
and the American religious broadcasts from Radio
Caroline, a pirate
radio ship moored out in the North Sea. But now I could hear American talk
radio over the internet. At last there was something new to listen to!
 A boys day out on the 'Ross Revenge' (Colin G3VTT, Tony G0PZX, Peter G4UJG and myself G4YJO) Talk
radio in the UK has always been restricted in what it can do or say,
but over in the States it's refreshingly open and free. Over there
they don't presume everyone's
stupid and pitch the conversation for the dumbest. They tell it like it
is and if you don't like it or understand it then
you can simply tune into another one of the hundreds of available stations. It's
free
speech and it's good, but we'd better make the most of it because it's
a blessing that won't be around forever
If the digital revolution has made worldwide communication so easy for everyone, is there really a need for conventional radio any more? Will anyone ever discover the thrill of hearing a voice from a distant country crackling over a loudspeaker when they have in their pocket a tiny communication device that can instantly connect them to anywhere on Earth with crystal clear clarity? I think not, and I understand why not. I find myself listening less and less to terrestrial broadcasting and more and more to online content for the same reasons. The old way has been superseded by something better, not in everyone's opinion granted, but the digitizing, storing and moving of data from place to place has way surpassed anything that could be achieved by analogue means, and the sheer convenience of it all will, if it hasn't already, send traditional methods of communication into the realms of nostalgia To be able to listen to what we want when we want is a joy. No longer being tethered to a radio schedule, the choice of time and content is ours, and with the broadcast gradually being replaced by the podcast, this ideal is encompassed perfectly. So it's with great affection that I remember my first homebrew radios, but at the same time, I'm thankful that I live in the digital age. The contrast is staggering but wonderful, and I'm looking forward to the technology of tomorrow. My only hope is that it will be for us and not against us |