AF4K Early Radio Experiences

Home Page

* Valves & Electronics *


It all began with Uncle Jack's TAPE RECORDER!

Actually it had started long before that with the family crystal set, the table-top radio with SW bands, reading Practic Wireless and Wireless World magazines etc.

As a small lad in the 1950s, I was surprised and delighted when after eating dinner at Uncle Jack's house, he invited us all to sit down and listen to what we had been saying BEFORE dinner. He had HIDDEN a microphone behind a chair in the living room and taped us all. Me, my brother, may parents and my grandmother! None of us had seen such a machine before, but within a couple of years, my brother and I both got one. His a 4-speed Philips, mine a BSR single speed cheaper one.

We had great fun with those, but I soon went on to make homemade intercoms, amplifiers, switchboxes etc. I even built a LIGHT BULB TESTER when I was about 10 years old and offered to test the neighbours' light bulbs for them - RIGHT! (no takers.)

At one point I bought an 8 watt amplifier by mail order. It was an open chassis affair of the type offered in "Exchange and Mart." It worked OK with this 8 inch speaker I had, but suffered badly from hum so I sent it back. The manufacturer worke don it and sent it back to me. They ahd mounted THE POWER TRANSFORME ON RUBBER GROMMETS! Of course the hum was still there! Nevertheless, I had fun with it, statling people by hiding the speaker in the hedge in front of our house. As pedestrains passed by on the footpath out the front, they were treated to some alarming sounds!

My brother played in jazz, rock and pop bands professionally from a very young age (10) - so I was always around amplifers and other electrical things and I helped set up the equipment for them, as well as helping to build and wire up/test their speaker cabinets etc.

Some lessons learned the hard way...
It wasn't long before I learned about tubes and transistors and what fun things you could do with each of them. I once bought some CAPACITORS from a parts shop because I thought they would AMPLIFY a signal! Nah! They were the old tubular WAX coated paper variety as I remember they smelled funny. About 0.1 uF for the design to feed headphones off a speaker output of a radio I think. You live and learn eh?

Later, I found that a school chum lived a few streets over from a TV repair place and we used to sift through their garbage after school. Often there were complete "TELLYS" laying around by the dustbin, and we would take tools and open them up, extracting ALL of the resistors, tubes, caps, even transformers, and of course the speaker!

High School Mischief!
Later I used some of these parts to make intercoms and radios. What fun, and all FREE! Kids at school used to make things, like.... Well, I remember the electric shock thing. They got an old matchbox (the large wooden kind) and mounted a small transformer in it, nad had an exernal 4.5 volt bicycle lamp battery underneath, and two tinfoil contacts on top.

They persuaded some unsuspecting numbskull kid to put his fingers across the contacts and then they flipped a wire together and apart, on the primary side of the transformer which of course induced a huge transient voltage in the secondary and zapped the mug!

Another gadget someone built, that impressed me, was a 1 kHz multivibrator that produced huge squarewaves using two transistors, and the harmonics from it would jam ANY radio receiver within a few yards. It ws great for annoying your school chums in the playground at lunchtime. These things were all of course, entirely clandestine. If the lads had been caught with such things at school they would have been punished I am sure! This was literally the school that inspired Pink Floyd's epic "The Wall." Yes, most of the members of that band attended our school (Cambridgeshire County High School For Boys.)

Later on, G3WUW used to bring a single transistor phase shift osc. and some headphones to school , and would teach me the morse code on the steps during lunchtime. We later did some tube building together and I did most of the work to make a 6AG7 - 5B254M transmitter. We also fired up a WS19 set with 10 watts of awful sounding AM!!

Here's what a 19 set looks like!


SOME of my valve activities (that's tubes for you colonial types!) from those old days of my teenage years in England... I built a 5 watt oscillator on the 27 MHz RC band. It had a wood cotton reel for the tank coil with about 5 turns. I believe that it was a simple Hartley oscillator design that I had found in an old issue of Practical Wireless. I only knew it worked because it interefered with Television sets!
HERE is a pictre of the unusual tube that was used in that very first transmitter:

Then there were the military 38 sets purchased from Proops in London, that we put on the air on 7 Mhz talking between "James One" and "James Two" - and the paranoia upon seeing a GPO "Radio-detector van" prowling the neighbourhood after school one day (grin!) These radios put out only 200 mW and used miniature tubes with battery power.

Here's what the Wireless Set Number 38 looks like!

Other early electronics memories:
Around 1962 (at the age of about 11 or 12) I was living in the suburbs of Cambridge, and went to a Boy Scouts "jumble sale" - just like a Flea Market in the USA. There I found for sale on one of the tables, a curious pair of valves. They were big, brand new RCA tubes in boxes with the number "805" on them. These things were big "bright emitter" bottles with huge, thick, carbon plate anodes. Now if I had known just what I had I would have guarded them with my life and put them to good use later! I have no idea where those valves wound up in the end. I probably traded them or sold them, but I DID have great fun lighting them up at home! I connected an old car battery to the filament connections and BINGO! Instant lighting for the room! I later found out that these were transmitting triodes good for about 300 watts each! I saw one the other day at a hamfest and ALMOST took it home!

In about 1964 we moved to the small, peaceful village of Cottenham, (population then was 2400!) situated about 8 miles N.E. of Cambridge. I remember going to visit the station of G3RFP, Fred who at that time worked in Technical Publications at Marshalls (where my dad was a draughtsman/design engineer) in Cambridge, England. I spent several Saturday mornings at Fred's house watching him run 10 watts of AM on Top Band with the local roundtable group. His transmitter had a large coupling coil to his end-fed half-wave antenna. It was about four inches in diameter with lots of turns. I became curious about all of the strange ham lingo! "QRM" - "QSB" - "73s" - "5 and 9" etc. Fred's receiver was a Heathkit HR-10. Those old UK AM operators were very polite. They all acted like nobility on the air. It was grand. There were no such thing in those days as 2 meter repeaters, and SSB was just coming into its own on the HF bands. All done with 10 watts of AM on 1.8 MHz.

I got to know the voices and callsigns of a number of local amateurs that way; the hams in Waterbeach, Cambridge, Newmarket and others in the villages around Cambridge. G5BQ, G3UUR, G2PU etc. etc.

My friend Allan (later G3WUW) at school taught me the morse code with his one transistor, phase-shift oscillator on the steps of our school at the "County High School for Boys" as it was then, during lunch breaks etc.! He lived in OVER, and I lived in Cottenham. I made trips to his house in OVER on my bike, and also to Willingham to the SWL shack of my friend David Gyp.

Allan and I also built some equipment for the 6 MHz CCF Net in those days, (Combined Cadet Force) in conjunction with some pals at the Lys School in Cambridge, using things like 6AG7s and 807s. Our callsign was WHISKEY LIMA. Or was that the "CALLUP signal" used like a CQ to contact other stations? I forget!I can remember hearing him BELLOW "WHISKEY LIMA, SIGNALS!!" into a carbon microphone on the old 19 set at the County High School after school one day. With HT+ of about 800 volts on the anode of the poor old ceramic base 807 valve glowing red hot! Oh and the power was from a dynamotor! The homebrew 807 rig came later. I did most of the construction on the darn thing, and the best I remember it DID actually work.

COMBINED CADET FORCE radio activities in England

I went numerous times to the Cambridge and District Amateur Radio Club in those days also, and learned a great deal from the lectures there. That's where I met G5BQ and many other local hams. It was a LOT of fun. Also, the club had a nice Eddystone receiver that was ham bands only.

While living in Cottenham, Cambridgeshire, at the age of about 13 I had a nice cozy SHED in the back garden of our house. It was a 5 ft. by 7 ft. edifice with an inverted "L" aerial made from a pievce of vertical gas pipe and a wire horizontal section.

My first receiver was a surplus model R1155A LANCASTER BOMBER RADIO that was used in world war two. I built the power supply for it on an old, round cake tin and it produced 250V DC and 6.3V AC for the heaters.

I built a power supply for it on a circular cake tin! This supplied 250 V DC and 6.3V AC for the receiver, and 5V AC for it's own HT rectifier, a 5U4.

Later on after getting my ham license, my family moved to Georgia in the USA and for a while I was inactive, but that did not last long!

Before too long I was able to acquire a Hallicrafters SX-99 receiver and a Knight T-60 transmitter:

Additional notes:

MANY British radio amateurs built their own equipment in those days or used military surplus. There was a LOT of that around in the 1960s still! And it was VERY cheap indeed. I am still building things today.
My 2 valve Transmitter is here.

A lot of the chaps used SCR-522 rigs on 2 meter AM, or if they were wealthy, had a PYE business band radio converted to 2m AM. There was no commercial/public service FM on VHF in Britain in the 1960s that I am aware of - it was all AM, a wonderful mode if you like the sound of warm, hi-fi, audio!

Later around 1985 or so I got interested in AM again. Thanks to the inspiration of (now SK) Roger Frith, N4IBF, who showed me his wonderful AM station consisting of a BC-610 / R-390A and 75A-4/ 32V-3 I was bitten by the AM bug! I soon acquired a Ranger, a Valiant and a Globe King 400. I never got the GK400 to settle down and stop self-oscillating in the V-70D triode finals so I never got it on the air! I wish I still had all three of those transmitters though! They sounded great on the air. Another great inspiration in thopse days was meeting Don, K4KYV from Woodlawn, TN.

When we moved from Tennessee to Maryland in 1987 I had to let go of a lot of my ham gear to move into a townhouse as I prepared to go to Bible College and change to a ministry career - something that never finally happened, but as they say: "That's a whole NUTHER story!"

  • Simple Low Power Valve Transmitters - Build One This year!

    73 from Radio AF4K / G3XLQ in Sanford, Florida

    Bry Carling, AF4K

    You are visiting the website at: