I return with more memories detailing moments and events that were prominent in my evolving journey into the world of radio and electronics.
In part two of my "trip down memory lane" and during 1979 I detailed my discovery of Citizen Band Radio, this introduced me to the world of two way radio communications and brought about a deep fascination in transmitting with a craving to build a transmitter myself.
In part two of my "trip down memory lane" and during 1979 I detailed my discovery of Citizen Band Radio, this introduced me to the world of two way radio communications and brought about a deep fascination in transmitting with a craving to build a transmitter myself.
Throughout the 70's and 80's the name Exchange and Mart was a household name in the United Kingdom. It was a weekly publication of classified advertisements reminiscent of a newspaper. This weekly publication was the go-to place to buy and sell anything from a pair of scissors to a house, it was the bygone alternative to Ebay!
I remember being very excited when the FM-100 kit arrived and I duly built the kit over a couple of days. In the schematic above, you can see where I drew some extra components in the output section. These components served as a dummy load, RF sniffer and a means of tuning the transmitter.
The finished transmitter produced around 100 MW of RF power from the output stage and was tunable from 70 to 150MHz. The wide tuning range was made possible by shorting the inner most turn of coil L1, which was printed on the PCB. For exacting applications the transmitter could be converted for narrow band frequency modulation (NBFM). This had be done with the addition of a quartz crystal but as this was not included in the kit, I never got to try this option out.
My completed kit worked the first time and I soon had it tuned up and transmitting to the domestic FM broadcast band for all and sundry to hear!
The first transmissions from my home built transmitter created a sense of Eureka and great satisfaction. I felt that I had made an achievement akin to that of Marconi, albeit without the notion of a Nobel peace prize, Marconi got there before me in 1909 :)
We were not unique in our approach to do portable two-way radio communications with separate TX & RX units. The police did this in the1960s when a UK company called PYE Telecom produced the ground- breaking PYE PF1 Pocketfone, Pye sold tens of thousands of the PF1's to the British Police.
When I first made contact with Ken on CB radio in 1980, it transpired that he lived locally to me and just a few minutes walk away. We enjoyed regular chats on the air discussing the finer points of radio and in due course Ken invited me to his house for a meet-up aka eyeball. I arranged to go and see Ken and from there on it became a regular social get together on a Sunday evening.
Ken was an ex-royal signals wireless operator so the emergence of CB radio in the UK rekindled his interest in communications. In 1980 CB radio was illegal in the UK and the majority of transceivers in use were either AM or multimode models covering AM, FM, and SSB. The multimode radios were difficult to acquire and alot more expensive and you were certainly the top dog if you owned one. SSB was predominantly used for long distance contacts and Ken wanted in on this and decided to buy himself a Yaesu FT-902DM which was actually a state-of-the-art ham radio transceiver built with transistors and valves. I remember going with Ken to purchase the FT-902DM, we had to wait sometime in the shop for the radio to be modified so it covered the 27MHz CB band.
Ken built himself a cubicle quad antenna for 27MHz and worked stations all over the world. Sunday evenings became the highlight of my week, as I got the chance to operate a big boys radio. The sunspot cycle #21 in 1980 was at a peak so radio propagation was fantastic and I feel privileged to have witnessed it and enjoyed radio communication at its very best!
I occasionally purchased a copy of the Exchange and Mart paper, as it often had interesting radio and electronics items listed. On one occasion I came across an advertisement to purchase a transmitter kit from a company called Welltex Manufacturing Co, I purchased the kit and it became my first ever home built transmitter.
I still have the original documentation that came with the kit, though the actual transmitter is long gone.
The FM-100 VHF/FM Transmitter
The FM-100 VHF/FM Transmitter Schematic
The finished transmitter produced around 100 MW of RF power from the output stage and was tunable from 70 to 150MHz. The wide tuning range was made possible by shorting the inner most turn of coil L1, which was printed on the PCB. For exacting applications the transmitter could be converted for narrow band frequency modulation (NBFM). This had be done with the addition of a quartz crystal but as this was not included in the kit, I never got to try this option out.
My completed kit worked the first time and I soon had it tuned up and transmitting to the domestic FM broadcast band for all and sundry to hear!
The first transmissions from my home built transmitter created a sense of Eureka and great satisfaction. I felt that I had made an achievement akin to that of Marconi, albeit without the notion of a Nobel peace prize, Marconi got there before me in 1909 :)
Any sense of achievement I had made was soon cut short by an unexpected interlude in my transmissions. My father entered the room and bellowed at me in an angry voice, "you're causing interference to the bloody television, the pictures breaking up and you're coming through the dam loud speaker," needless to say, I ceased transmitting with immediate effect. My broadcasting may have been cut short but I was in awe at what I had achieved & done, not only could I be heard on domestic radio but on television as well!
 |
The Radio Ga Ga Effect! |
Avid readers of the blog and those in the know will have deduced from the schematic diagram that the transmitter lacks any filtering on the output stage. Without filtering I was orchestrating a symphony of harmonics and reaching out to a wider audience through neighbouring television sets.
The television interference was not welcomed by my father nor my neighbours and it soon became evident that I could not transmit during peak TV viewing times.
Both my brother and I had a lot of fun with the FM-100 transmitter. I remember connecting a tape recorder to the transmitter and playing music over the airwaves while we went off on our push bikes to see how far away we could receive our transmission. I recall that we could receive the signal from our transmitter from a good mile away so we were now "pirates of the airwaves".
It was not long after I built the FM-100 transmitter kit that I became conversant in making my own printed circuit boards. Back then I produced my PCB's using rub down transfers and an etch resistant ink pen. The artwork was created directly on to the copper-clad board and then etched in a ferric chloride acid solution. The process was slow and not always successful so I often had to repeat the task in order to get a satisfactory end product.
Despite my hit and miss attempts at creating PCB's I set about reproducing the FM-100 circuit board so that I could build a second transmitter. My endeavours soon came to fruition; I successfully made a duplicate PCB, sourced the components and built transmitter number 2.
Having built a pair of the FM-100 transmitters, the prospect of two-way radio communication was a very exciting prospect requiring the addition of a couple of radio receivers. Soon both my brother and I were on the air making two-way radio communications chatting away on the domestic FM broadcast band oblivious to the fact we were now radio pirates and operating contrary to forbidden law.
Initially, our transmitters were built into independent abs project boxes. For receiving we used separate commercial portable pocket FM radio receivers. This meant that we had to carry two pieces of equipment around and our hands were full. This was not ideal for our push bike mobile activity!
We were not unique in our approach to do portable two-way radio communications with separate TX & RX units. The police did this in the1960s when a UK company called PYE Telecom produced the ground- breaking PYE PF1 Pocketfone, Pye sold tens of thousands of the PF1's to the British Police.
 |
We soon got fed up with lugging two boxes around and came up with the idea of stripping the commercial pocket radios down and re housing them into suitable project boxes along with the FM100 transmitters. We ended up with a pair of "walkie-talkies" about the size of a house brick but back in the late 70's this was considered miniaturized!
In operation our walkie-talkies had a tendency to drift in frequency so occaisionally we had to re-tune the receiver frequency to maintain contact. This was no big deal, as we had full manual tuning of the entire domestic FM broadcast band. We had a lot of fun using the walkie-talkies and I have particular fond memories of taking them on family holidays and operating them on the beach along the North Wales coastline.
It is not a good idea to operate a transmitter illegally and I ask that in my case you make allowances for the fact I was young, care free and to some degree stupid "but hey" it was a whole load of fun :)
In part 2 of my trip down memory lane, I mentioned a chap called Ken Lane, who I became acquainted through Citizen Band radio, Ken became a great friend and my mentor into the world of amateur radio.
Ken was an ex-royal signals wireless operator so the emergence of CB radio in the UK rekindled his interest in communications. In 1980 CB radio was illegal in the UK and the majority of transceivers in use were either AM or multimode models covering AM, FM, and SSB. The multimode radios were difficult to acquire and alot more expensive and you were certainly the top dog if you owned one. SSB was predominantly used for long distance contacts and Ken wanted in on this and decided to buy himself a Yaesu FT-902DM which was actually a state-of-the-art ham radio transceiver built with transistors and valves. I remember going with Ken to purchase the FT-902DM, we had to wait sometime in the shop for the radio to be modified so it covered the 27MHz CB band.
 |
| YAESU FT-902DM |
Ken built himself a cubicle quad antenna for 27MHz and worked stations all over the world. Sunday evenings became the highlight of my week, as I got the chance to operate a big boys radio. The sunspot cycle #21 in 1980 was at a peak so radio propagation was fantastic and I feel privileged to have witnessed it and enjoyed radio communication at its very best!
A look back at life in the UK during 1981 revealed some interesting facts:
- The first London marathon is held.
- Rupert Murdoch buys The Times And The Sunday Times Newspapers.
- Bucks Fizz win the Eurovision song contest with Making Your Mind Up.
- Riots spread across towns and cities throughout England.
- Arthur Scargill ellected as leader of the National Union of Mineworkers.
- The pioneering ZX81 home computer is launched by Sinclair Research.
- Enoch Powell warns of "racial civil war" in Britain.
- Unemployment passes the 2,500,000 mark for the first time in nearly 50 years.
1981 was an important year for myself, as it was the year I would set about my journey to become a licenced Radio Amatuer. My mentor Ken Lane had unknowingly to myself enrolled for us both to sit for the City and Guilds “Radio Amateur Examination” (RAE) at Openshaw technical college located in Manchester.
The plan was to self teach ourselves and prepare for sitting the exam, which we went on to do later during the year. Ken bought a couple of books from the Radio Society of Great Britain that were considered a useful reference and an aid to help pass the RAE. Over a period of months, we worked our way through the radio publications and prepared for our exam day.
At the time the City & Guilds RAE was a two part two paper examination; Part 1 dealt with licencing conditions, interference, and EMC, Part 2 was more technically orientated dealing with procedures and theory. Nowadays the examination process is handled by the Radio Society of Great Britain and it is much easier to obtain a licence. There are now three different tiers of the licence, foundation, intermediate and full, with the latter being the replacement for the City & Guilds.
We took both parts of the exam in a single sitting, a fail in either or both papers required that the paper or papers failed would have to be re-sat at a future date. The approved City & Guilds exam centres held exam sittings twice a year so the prospect of a failure would mean a wait of many months before the paper(s) could be sat again and the end results received. At the end of our exam, I felt confident that I had done okay, my existing interest in electronics certainly helped with the technical side of things.
I recall that we waited about five weeks for our exam results to come through and when they finally dropped through the letterbox, there was a sense of trepidation to open the envelope and reveal my ham radio destiny!
I opened the envelope and on reading the contents I endured and overwhelming sinking sensation with flashbacks of the TV sitcom Dad's Army and Private James Frazer uttering those immortal words,
"We're doomed!"
Now at this point you may be thinking I failed the exam but this was not the case, I had written confirmation that I had passed part one; however, there was bad news regarding part 2; an accompanying letter with my pass paper brought bad news, my part two exam papers had been lost in transit during a train journey to London along with several other candidate papers, I felt doomed, frustrated and annoyed.
The only consolation in light of my disapointment was the offer of an opportunity to sit the exam again free of charge at the next available sitting. As the exam sittings were carried out twice a year, I knew I would have to wait some five months to do the exam paper again. My friend Ken was fortunate, his exam papers were not in the batch that went a stray and he passed his exams and was allocated the callsign G4OLD Well done Ken!
The five month wait to take my RAE exam felt like an eternity but finally the day arrived and Ken kindly took me back to Openshaw Tech and I sat the exam again. A few weeks later I received the news that I had passed my exam and I was able to apply to Ofcom for my licence and callsign. At the age of 16, in 1982, I was allocated the ham radio callsign G6LBQ. As I wrote this memoir on January 17th 2020 I have been a licenced Radio Amateur for some 38 years.
During my time as a radio ham, I have witnessed many changes within the hobby and, in particular with the technology that continues to evolve year after year. In 1982, when I became licenced, most communications were done via radio. The Internet was an emerging technology used only by the military and academia. Nowadays the predominant means of communication is the internet with global networks that link us all together. These same global networks have brought about massive changes to the world of amateur radio with infrastructure that connects countries, cities and states together and throughout the world. Back in 1982 no one could envisage that in current times a radio ham could work the world from a mere handheld transceiver and do this any time of the day and on any day of the week 365 days a year!
Whist all modern digital technology and the internet has done wonders for connecting us all together, it has come at a price that affects the radio ham or listening enthusiast with serious consequences!
At the time the City & Guilds RAE was a two part two paper examination; Part 1 dealt with licencing conditions, interference, and EMC, Part 2 was more technically orientated dealing with procedures and theory. Nowadays the examination process is handled by the Radio Society of Great Britain and it is much easier to obtain a licence. There are now three different tiers of the licence, foundation, intermediate and full, with the latter being the replacement for the City & Guilds.
We took both parts of the exam in a single sitting, a fail in either or both papers required that the paper or papers failed would have to be re-sat at a future date. The approved City & Guilds exam centres held exam sittings twice a year so the prospect of a failure would mean a wait of many months before the paper(s) could be sat again and the end results received. At the end of our exam, I felt confident that I had done okay, my existing interest in electronics certainly helped with the technical side of things.
I recall that we waited about five weeks for our exam results to come through and when they finally dropped through the letterbox, there was a sense of trepidation to open the envelope and reveal my ham radio destiny!
I opened the envelope and on reading the contents I endured and overwhelming sinking sensation with flashbacks of the TV sitcom Dad's Army and Private James Frazer uttering those immortal words,
"We're doomed!"
Now at this point you may be thinking I failed the exam but this was not the case, I had written confirmation that I had passed part one; however, there was bad news regarding part 2; an accompanying letter with my pass paper brought bad news, my part two exam papers had been lost in transit during a train journey to London along with several other candidate papers, I felt doomed, frustrated and annoyed.
The only consolation in light of my disapointment was the offer of an opportunity to sit the exam again free of charge at the next available sitting. As the exam sittings were carried out twice a year, I knew I would have to wait some five months to do the exam paper again. My friend Ken was fortunate, his exam papers were not in the batch that went a stray and he passed his exams and was allocated the callsign G4OLD Well done Ken!
The five month wait to take my RAE exam felt like an eternity but finally the day arrived and Ken kindly took me back to Openshaw Tech and I sat the exam again. A few weeks later I received the news that I had passed my exam and I was able to apply to Ofcom for my licence and callsign. At the age of 16, in 1982, I was allocated the ham radio callsign G6LBQ. As I wrote this memoir on January 17th 2020 I have been a licenced Radio Amateur for some 38 years.
During my time as a radio ham, I have witnessed many changes within the hobby and, in particular with the technology that continues to evolve year after year. In 1982, when I became licenced, most communications were done via radio. The Internet was an emerging technology used only by the military and academia. Nowadays the predominant means of communication is the internet with global networks that link us all together. These same global networks have brought about massive changes to the world of amateur radio with infrastructure that connects countries, cities and states together and throughout the world. Back in 1982 no one could envisage that in current times a radio ham could work the world from a mere handheld transceiver and do this any time of the day and on any day of the week 365 days a year!
Whist all modern digital technology and the internet has done wonders for connecting us all together, it has come at a price that affects the radio ham or listening enthusiast with serious consequences!
WARNING CHRONIC RADIO INTERFERENCE!
We live in a world with an ever-increasing number of modern electronic devices at our disposal so it is inevitable that radio interference is on the increase and here to stay. Items like computers, LED lighting, internet modems, switch mode power supplies, phone chargers, solar panels and many other electronic devices are all potential sources of radio interference.
This interference can represent itself in the form of blank carriers, signals with unidentifiable types of modulation or excessive receive noise levels. The interference can sweep up and down parts of the radio spectrum or just block out specific frequencies or bands and it may come and go at different times of the day.
Dealing with unwanted radio interference is not something I want to deal with in this blog post however,
do be aware that the source of interference may well be well within your reach!
Well, there you have it I conclude my memoirs about how I got started in the wonderful world of electronics and became a radio amateur. My journey is far from over and my intention is to continue the blog with electronics and radio content and a diary of my homebrew projects.
Until next time...
73's From Andy G6LBQ
Its all about the Radio Ga Ga...
A 1st rate blog Andy, interesting read and to the point,
ReplyDeletekeeping a lookout for more of your antics (HI) up and down