Friday, 28 February 2025

Fifty years an amateur started here

 On 4 February 2025 I reflected on this being the 50th anniversary of me becoming a licensed radio amateur.

I have already explained at very great length here https://gm4fvm.blogspot.com/2018/09/vhf-1970s-style.html  what I was confronted with once I got that licence. This posting is about the exam itself.

The run up to this was 10 years as a short wave listener, building crystal sets (and more) from Philips and Sinclair Radionics assembly kits. On 2 December 1974  filed into a hall in London to sit my Radio Amateurs Examination (known as the RAE). I cannot recall now, but I think the hall belonged to the City and Guilds of London Institute, the body which ran the RAE in those days.

I had not taken the precaution of having any formal training before taking the exam. I was self taught, apart from Physics lessons at school and reading several books. I recall "Understanding Amateur Radio" from the ARRL, a book which seemed out of date to me at the time. I bought it second hand and still have it. Back in 1974 we had the choice of drawing valvised or transistorised  circuits in the RAE, and my preference was for the valve versions - the ARRL book was from the valve era and that was what I was learning.

That day in 1974 a total of 720 candidates sat for their RAE in various examination halls all round the UK. Of the 720, 475 would pass the examination. At 66% the pass rate was not too bad. Looking around me, although I did not know anybody, I did wonder who might pass. They all looked fairly well prepared, and I was not. Still, the Institute did allow you to use a set of logarithm tables, which I doubt would make much sense to current candidates.

Back then there were two formal exams each year. In May 1974 a further 1719 had taken the exam. Traditionally the May exam came at the end of a formal course of evening classes over the Winter and the pass rate was slightly lower at 62.9%. Some people re-sat the exam in February after failing in May, so the pass rate in February was often marginally higher thanks to people who were trying for a second time. 

In 1974 a total of 1506 people passed the RAE. The number passing had been about that figure each year since around 1968. Before that it is hard to generalise. The RAE was introduced in 1946 and in the early Post-War years a lot of amateurs qualified for a licence without taking the RAE thanks to military service in a related trade. After 1978 there was a bulge in numbers which is usually put down to a craze for CB introducing many to radio. Anyway, in 1982 more than 8000 qualified before a long decline until in 2002 the figure fell to under 300. The last RAE was in 2003, after which changes took place and eventually our current multiple choice tests and the three tier system emerged.

The RAE in my day consisted of a three hour written examination starting at 18:30 in the evening. There were two parts - Part One had two questions, and both of those were compulsory. Part One was about licence conditions. In Part Two you could choose to answer any six out of eight technical questions. This meant for me that I could avoid my two weakest technical subjects by picking the right questions in Part Two.

Part One carried more marks per question than Part Two. Although there were only 25% of the questions on the paper to answer from Part One, it carried 33% of the marks. In any case, if you failed either part you failed the whole exam. The idea here must have been that however technically minded you were, you still needed to know the licence conditions. 

Apologies for the quality of the exam paper below but I do not have it in a format which can be uploaded to this site. I have had to make screengrabs of an already scrappy scan. If you click and enlarge it it should be readable. In any case I will try to summarise the question in the text of this posting.

Fortunately, ten years as an SWL had made me fairly competent about the way amateur radio was regulated. Those two questions from Part One were fairly easy for me - I knew that receivers were not meant to transmit (radiating spurious signals was a big thing back then), the regional prefixes were all around me, and the phonetic alphabet was what I heard every day. From my ARRL book I knew how to filter transmitter outputs (on single band transmitters anyway). So Part One was fairly easy to deal with. 

Part Two was not so easy. I had to select two questions on my weakest areas, and then avoid them. This came down to a selection between three:-

Question Four - draw the circuit diagram of the output stage of a multiband transmitter and explain its metering. This was not great for me as I had been looking mostly at single band transmitters. In those days multiband transmitters had multi wafer band switches with rods running right from the knob at the front to the back of the rig with connections going it all directions. 40 years later I was to have a multiband SDR transceiver with only one control (on/off) and I was finally comfortable.

Question Seven - what is dynamic impedance of a parallel tuned circuit, draw a diagram of impedance with frequency and show response curves for CW and DSB. Tuned circuits have always been tricky for me. I knew how they work, I knew the principles, but a first glance this looked like a difficult one to do in detail.

Question Eight - draw the circuit diagram of the demodulator and agc of an hf receiver, and describe how agc voltage is derived and applied. I wasn't ready for this one. This had not come up in the old papers I had read. Sure I had built many receivers as an SWL, but none of them had automatic gain controls (maybe a reactance control!). I knew what an agc was OK, but I was not ready to draw that diagram.

So question eight was out for sure, and the choice was between questions four and seven as to which other one to drop. Never having built a transmitter (which SWL had?) meant that question four was clearly going to be difficult. So it was likely that I would have to try to answer question seven.

[ err, I had built a transmitter, out of the Radionic kit, but it was medium wave only and did not have a lot in the metering department. Of course, being unlicensed I never used it ...  honestly]

Right, subject to more thought later, it was time to start answering the ones I reckoned I could do.

Question Three - describe a directional aerial suitable for 144 to 146MHz and in what circumstances is a directional aerial desirable. While I had never used a directional aerial I knew how they worked (all those TV antennas all around me). Even I knew that a non-directional aerial would be better if you were expecting signals from all directions and a directional one for situations when you wanted more gain in certain directions, but then you might need to turn it.

Question Five - FM. I just churned this one out. Based on previous papers I had been expecting it. Perhaps for that reason before the exam I went round to the RSGB in Doughty Street and bought a copy of the then new RSGB "NBFM Manual". I still have that spiral bound book.

Question Six - Block diagram of a superhet receiver. I knew this one quite well and I had been expecting it. I simply trotted out the diagram of my Trio JR599. When, 30 years later, I was training new amateurs for their exam I found that I could still draw it from memory.

Question Nine - What frequency to use at 50, 1000 in darkness in winter, and 5000 miles in daylight. Meat and drink to a seasoned short wave listener. I went to town on this one.

Question Ten - resistor values in an amplifier circuit. I had not expected to see a transistor circuit but still this was ohms law and something I had carried forward from Physics at school.

So that was five done and I needed to finally decide of the sixth. Hmmm. Still a choice between questions four and seven. I realised that I only had ten minutes left so this was going to have to be a partial answer anyway. That was an even stronger reason to do question seven. I knew what the response a receiver should have for narrow and wider reception and I knew enough about impedance of a tuned circuit to have a go, though there was not going to be much detail. I just wrote what I could.

I was still writing furiously when "pens down" was called. I had managed to write for almost all of the three hour period and only paused during thinking time about which would be my sixth question.

Did my exam strategy work? Well I had expected to be able to answer six in Part Two and it should have been easy to rule out two. I found that only five were as expected and I had to choose one to answer in Part Two from those three, none of which I could not do easily. However, even if I had known more about the last answer I ran out of time anyway. So that was it and we would see what happened next.

Over the years I learned how to approach three hour examinations. As I found later at university where 39% was a fail and 40% was a pass - 40% will do me nicely. I never was, and never wanted to be, a honours student. Probably because I never could be.

Somewhere in my archive I still have a the pass slip which I received from the City and Guilds in January 1975. I recall a telephone conversation with my father after I had passed. I had not even told him that I was taking the exam, perhaps because I did not think that I would pass. He was impressed by what I had done (which is the only time I recall that happening).

So I received my Class B (i.e. VHF phone only) licence callsign G8JWG, on 4 February 1975.

Anybody who has gone through the current licensing process might wish to ponder over what we used to have to do. The three hour written exam which was only held twice a year. You had to choose which questions to answer in Part Two, and you never knew what mark you got (unless you got a distinction, which obviously I did not). All you knew was whether you had passed or failed. So if you had to re-sit, you never knew what to do better.

The rest, as they say on a very good podcast, is history.

73 Jim

GM4FVM

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