50 Years of 50 MHz  - Ken Willis, G8VR

Following my article `A Bit of History' in `Six News' 67, the Editor suggested I contribute a few pieces under the above title. Few current members of UKSMG will go back fifty years, but some of us do and there were lots of interesting things happening on and around six metres all those years ago. From time to time I will try to relate some of them, though not necessarily in chronological order, selecting topics of general interest which illustrate the huge strides made in radio communication at wavelengths below ten metres over the past half-century. The introduction of Band I television in the UK in the years just prior to and following World War II, meant the `Magic Band' did not become available to British amateurs until the
1980s. So perhaps I can be forgiven if I sometimes cheat a little by assuming that 50 MHz is only `Approximately Six Metres' (see `Six News' 40), thus allowing me to sneak in some interesting related stories.

Ken Ellis, G5KW and MD5KW
If, as the Bible suggests, Man's stay on the planet is three score years and ten, a teenager bitten by the radio bug could hope to experience at least five solar cycles. One man who has already lived through more than his share of solar cycles, and in so doing has written whole chapters of six-metre history, is Major K E S Ellis MBE - better known to us as Ken Ellis G5KW, a founder member with Steve, G4JCC of the UK Six Metre Group.

Ken Ellis, G5KW in his shack.

Ken, pictured in his shack, is now 92 and lives in Kent. He joined the army as a boy and left it with the rank of Major, Royal Signals. His military and subsequent business career took him into some fascinating parts of the world, and wherever he went his radio equipment was never far away. He held a number of exotic callsigns much in demand on the HF bands, but his particular interest - propagation at frequencies above 28 MHz - was aroused in 1939. By this time he had been posted to Egypt and was operating as SU1KE, but the outbreak of World War II brought his amateur radio activities to a halt. During the war his main sphere of military operations was in the Middle East, an area he came to know and understand very well and where later, as a civilian, he was to spend several years working as a consultant in the communications field.

In 1946, serving with 3GHQ Signal Regiment at Fayid in the Suez Canal Zone, Ken was in control of a military communication network known as the Army Wireless Chain and he had several radio amateurs on his staff. Monitoring 49 MHz television signals from India, together with harmonics of service and commercial stations, in his spare hours led him to conclude that there was potential for long distance propagation on six metres along a north-south path across the equator.

By now, GHQ Middle East had begun to allocate amateur radio licences and calls and Ken received the call MD5KW, which later became so well-known among the 50 MHz fraternity. At the time, operators in a number of countries around the world (notably the USA) were active on the 50 MHz band. But television demands still meant that UK amateurs were
excluded from six-metre operation and instead were allocated 58.5-60.0 MHz, a much less attractive part of the spectrum from an MUF standpoint.

To investigate the equatorial path on 50 MHz, MD5KW built a station for 28, 50 and 58.5 MHz. From early 1946 he transmitted a beacon signal on 50 MHz from a four-element directional array which beamed alternately north and south, changing at thirty-minute intervals driven by a modified prop-pitch motor. Less-ancient readers may not know that these motors, which as their name suggests were used to vary the pitch of aircraft propellers during flight, were freely available as surplus items after the war and easily converted into antenna rotors. The MD5KW project attracted considerable interest from various military units in the area, to the extent that the RAF loaned a cabin and a 50-foot wooden tower for the antenna, close to the Officers' Mess.

Initially, the receiving end of the project was located a few miles away. Ken has not told me how he kept a continuous watch on 28.100 MHz for cross-band calls to report reception of his six-metre beacon signal. Perhaps he arranged a `training' programme to assign all signalmen of the 3GHQ Signal Regiment to man the station on a shift basis! Up to the autumn of 1947 several reports of reception of the beacon had been received from Europe and South Africa and later from German stations. Nothing was heard in the UK until October 19th when it was copied by G5BY in Devon who, lacking a 50 MHz licence, could only reply on 28 MHz.

As mentioned in `A Bit of History' (Six News 67) great efforts were being made in the UK at this time to obtain a 50 MHz permit for G6DH to allow him to make the first transatlantic contact on the band. This was finally granted on November 5th 1947 and he made the contact with W1HDQ the same day.

Two days later G6DH worked MD5KW two-way on six metres. Here is how Ken described the moment: "I was on parade with my squadron at 10.00 am local time for an Annual Review of the Regiment by the Chief Signal Officer. An orderly informed the adjutant that Major Ellis was wanted urgently on the telephone to speak to the Receiving Station. I asked permission to leave the parade and went to the Officers' Mess. Not knowing what to expect, I was told that G6DH had been receiving my six-metre beacon for the past 20 minutes at strength 599. I quickly went outside to the ham shack and started calling. G6DH came back, reporting my CW as 599. His phone was S9 plus 20 dB."

I understand that in the Mess that evening, when the Chief Signal Officer learned the content of the urgent message which had taken Ken from the parade, he was fully appreciative of the significance of the event. He was apparently aware that, to paraphrase a comment attributed to Bill Shankley the late Liverpool FC manager, "Six Metres isn't a matter of life and death-it's much more important than that!"

By today's standards, the equipment at MD5KW was very basic. Only the receiver, a Hallicrafters S27, was a piece of commercial equipment - one of the few available receivers that could tune to VHF frequencies. We didn't know much about noise figures in those days but I would be surprised if it was better than 6 dB.

Ken as MD5KW, operating his beacon station in Fayd in 1947.

The transmitter was a `breadboard' layout typical of the period. It used a VFO (electron-coupled 6V6) into 6V6 doubler stages and finally an 807 driving a single HK24 triode, which was a power amplifier on 28 MHz and a doubler on 50 MHz. Because it was required to operate on both 28 and 56 MHz, the `tank' or final amplifier coil seen top-right of the rig was a plug-in type, changed between bands. In those days any station worth its salt would have a tank coil at least three inches in diameter wound with copper tubing (the sort used for the petrol supply in Austin Seven cars), this being regarded as essential to obtain a high Q. With 35 watts output on 50 MHz, the spacing between vanes of the final tuning capacitor, visible in the photograph, seems adequate to make a flashover an unlikely event.

Footnote: On November 5th 1947, following a day's cross-band operating, G5BY built a complete six-metre transmitter overnight, finishing it at 0400 hours! There is much more to tell about G5KW and other six-metre early-birds.

UKSMG Six News issue 69, May 2001