CHAPTER NINE

MISCELLANY

The first broadcasting stations of the world.

Speech was first transmitted for reception by the general public from Washington D.C. in 1915 when Europe was still at war. During 1916 the first `broadcasting' station in the world began regular transmissions from a New York suburb.

In 1919 Dr. Frank Conrad, then Assistant Chief Engineer of the Westinghouse Electric & Manufacturing Company, set up, in his own garage in Wilkinsburg, Pennsylvania, a 75-watt transmitter (8XK) from which he broadcast musical entertainment for other radio enthusiasts. This was the first continued scheduled broadcasting in history. The Westinghouse Company realised the potential value of Conrad's work and built KDKA, the first regular commercial broadcasting station in the world, which began its career by announcing the results of the Harding-Cox election returns on the November 2nd 1920.

The first broadcasting station in Europe was PCGG which began transmitting on November 6th 1919 from the Hague in Holland. Hanso Steringa Idzerda, a 35 year old engineer, obtained the first licence granted in Europe for the transmission of music and speech for general reception, as opposed to the wireless telegraphy stations which had been operating point to point services. From the end of 1919 to 1924 this station transmitted a series of musical programmes three times a week called `The Hague Concerts'. The original wavelength of 670 metres was later changed to 1,150 metres.

At that time most of the people who heard these concerts would have been using headphones and they would not have been very critical about the quality of the sounds they were hearing compared to the magical novelty of snatching voices and music apparently out of thin air. This historic transmitter can be seen in the museum of the Dutch Postal Services in the Hague.

The first transmissions of speech and music in England were made from Chelmsford, Essex, when a 15kW transmitter of the Marconi

Company began regular transmissions in February of 1920.

In the summer of 1924 the world's greatest radio companies - British Marconi, German Telefunken, French Radio Telegraphie and American

R.C.A. - met in London to discuss transatlantic communications. The learned gentlemen all agreed that the Atlantic could only be spanned by ultra-long waves of 10,000 to 20,000 metres, which would require the use of hundreds of kilowatts of power and receivers as large as a trunk, not to speak of antennas more than a mile long. Dr. Frank Conrad, who was also present at the conference, had brought with him a small short wave receiver less than a foot square. When he connected it to a curtain rod as an antenna the faint but clear voices of his assistants in the U.S.A. were heard from nearly four thousand miles away. With this spectacular demonstration he administered the deathblow to all plans for high power ultra-long-wavelength transmitters, and from then on the commercial companies concentrated their efforts on developing equipment for international communications on the short waves.

With present-day electronic news gathering and world-wide satellite links, the problems faced by broadcasting organisations fifty years ago when transmitting programmes which did not originate in a studio were thought to be very complex. In the B.B.C. Handbook for 1928 there was an article entitled `Outside Broadcast Problems' which said,

"Work outside the studio is often the most difficult that the broadcast engineer can be asked to undertake; not so much from a technical as from a practical point of view. Very often he has to take his apparatus to some place he has never seen before, set up his amplifiers in most awkward positions, test his lines to the studio, decide on his microphone placings and run out the wiring in the space of an hour or so, with little previous experience to guide him. It is in fairly echoey halls, theatres and churches that the majority of outside broadcasts take place. For example, a sermon preached in a church would be intelligible probably to the whole of the congregation. But to render it intelligibly on a loud-speaker, the microphone would have to be, say, not more than ten feet from the speaker. In broadcasting a play from a theatre, when the speakers are moving about, the only way of dealing with the problem is to use several microphones

and a mixing device which enables the engineer to change silently from one microphone to another, or to combine them in varying proportions. Some rapid switching may sometimes be necessary.

"Even with good microphones and amplifiers the engineer in the field may often experience difficulties with the lines connecting the outside point to the studio. The majority of such lines do not transmit the higher frequencies adequately, especially the longer ones. The problems become immense when European simultaneous broadcasts are attempted. Experiments on the continental wireless link have done no more than reveal its unreliability. The undersea telephone line, however, does not give either good or even intelligible quality of speech if it is longer than a couple of hundred miles, and it is quite unusable for the transmission of a musical programme.

"The B.B.C. has been the first in the world to exploit Simultaneous Broadcasting to its fullest advantage for a national system, and thanks to the co-operation of the Post Office engineers, it is possible to pick up a programme wherever it may take place within the British Isles and radiate it simultaneously from all distribution centres.

"Looking ahead still further and assuming that the wireless will supplement the wire line link, there is no reason why a simultaneous broadcast of something of fundamental importance to the whole civilised world should not take place some time in the future."

In a book entitled "Radio Goes to War" published by Faber & Faber in 1943, Charles J. Rolo wrote,

"Radio went to war on five continents shortly after the Nazi Party came to power in Germany. In nine years it has been streamlined from a crude propaganda bludgeon into the most powerful single instrument of political warfare the world has ever known. Spreading with the speed of light, it carries the human voice seven times round the globe in one second. When Hitler makes a speech in the Kroll Opera House in Berlin, listeners in America and the whole world hear his words by short wave even before his own immediate audience hears them. Radio speaks in all tongues to all classes. All pervasive, it penetrates beyond national frontiers, spans the walls of censorship that bar the way to the written word, and seeps through

the fine net of the Gestapo. It reaches the illiterate and the informed, the young and the old, the civilian and the soldier in the front line, the policy makers and the inarticulate masses. So great is the importance of radio to- day that the seizure of a defeated nation's transmitters has become one of the primary spoils of war."

In Greece, broadcasting was started in the northern city of Thessaloniki (Salonica) by the pioneer of Balkan broadcasting Christos Tsingeridis, in 1928. A museum in that city tells the full story of the first broadcasting station in the whole of the Balkans.

Broadcasting in the capital, Athens, started on March 25th 1938 when a second-hand 15 kW Telefunken transmitter was put into operation in the suburb of Liosia. The centre-fed T antenna was supported between two pylons of 85 metres (279 feet). In 1944 when the German army was pulling out of Athens they tried to blow the the pylons up but one of them remained standing at a crazy angle, because one of the explosive charges had been placed incorrectly.

Avlis `The Voice of Hellas'.

The 5th Programme of the Greek broadcasting service (Elliniki Radiophonia) is transmitted from the short wave transmitting centre at Avlis, about 70 kilometres north of Athens. The station was put into service in 1972 and has two 100KW Marconi short wave transmitters and a veritable forest of antennas covering 1,100 acres, arranged in three lines to cover the desired directions, as can be seen on the great circle map. The pylons supporting the 6 MHz arrays are truly impressive at 328 feet. Each line has eight separate antennas for the 6, 7, 9, 11, 15, 17 and 21 MHz broadcasting bands.

Each antenna consists of two curtains with a total of 8 horizontal dipoles. The dipoles are all fed by open wire feeders which can be remotely switched to enable radiation in two directions 180 degrees apart. There are also three curtains for the 11 metre band (26 MHz) which may be put into service during sunspot cycle 22 if the M.U.F. allows it.

For transmissions to neighbouring countries like Cyprus, Turkey, the Balkans and the countries of the Middle East, there are two rotatable log periodic antennas with a high angle of vertical radiation (45 degrees) and a

wide angle of 32 degrees in the horizontal plane.

The remotely controlled switching centre allows each of the two transmitters to be connected to any one of the 23 antennas. Electromechanical protection circuits ensure that a transmitter can only be connected to an antenna that is tuned to the same frequency. The change of antennas and transmitting frequencies is made during the ten-minute interval between programmes, which always begin on the hour, preceded by the now familiar signature tune of a shepherd playing his flute with the tinkling of sheep-bells in the background, recorded in 1936, followed by the Greek National Anthem.

The special programmes of news and features originate in the broadcasting headquarters in Athens and go on the air throughout the 24 hours of the day in Greek, English and many foreign languages. Reports of reception are welcome and should be addressed to K.E.B.A., Avlis, Greece. (The Greek initials stand for short wave transmitting centre.)

But Avlis was `in the news' long before the Greek broadcasting service decided to install its short wave transmitters there. In ancient times a great fleet of ships had been assembled in the harbour there, ready to set sail for Troy, following the abduction of the beautiful Helen of Sparta by Paris, the young Prince of Troy. But there had been no wind for many weeks, and the sea was dead calm.

Agamemnon, the King of Mycenae, who had himself contributed over 100 ships to the fleet, decided to consult his Seer. As was the custom, the Seer slaughtered a young lamb and scrutinised its entrails. He then announced that the wind would come up if Agamemnon sacrificed his daughter Iphigenia on the Altar of Sacrifice. King Agamemnon despatched a messenger to Mycenae (no VHF repeater being available in those days) to tell his wife Queen Klitemnestra to send their daughter Iphigenia to Avlis (Aulis). The King said he was planning to marry her off to Achilles, the most eligible bachelor of the day. When poor Iphigenia arrived she was quickly placed on the Sacrificial Altar - and had her pretty throat slit.

However, there seems to be another version to the end of the story. Just before the human sacrifice was due to be made Artemis (Diana, the famous Goddess of Hunting) sent a small deer which was placed on the

altar instead of the girl. Iphigenia was secretly spirited away to Taurida, in northern Greece, and put in charge of Diana's temple there.

(This story is the subject of a well-known classical Greek play.) Historical note on the Marconi-Stille steel tape recording machine.

At the beginning of the century Professor Poulsen, one of radio's earliest pioneers, discovered that a magnetic impression could be made on a moving length of wire which remained on the wire even after it had been rolled up. He used his machine to record the Morse code only, that is magnetism `on' and `off'. In 1924 Dr. Stille in Germany made a machine which could record sounds. The B.B.C. sent two engineers to Berlin, and after a demonstration they offered to buy the machine, but in the end they returned to England empty-handed.

In 1931 Mr Louis Blattner managed to buy a machine and bring it to England. He called it the Blattnerphone. By this time Dr. Stille had replaced Poulsen's wire with a flat steel tape 6 mm wide. Each reel of tape could only accommodate 20 minutes of recording. There was a constant and heavy background hiss, due to the inherent quality of the steel tape itself.

Stille Inventions Ltd. joined forces with Marconi's Wireless Telegraph Co. Ltd. to produce, with the close co-operation of the B.B.C. Research Department, the Marconi-Stille machine which was put into use in 1934. The tape width was reduced to 3 mm and the thickness to only

0.08 of a millimetre. In order to secure the reproduction of the higher audio frequencies, it was found necessary to run the tape at a rate of 90 metres per minute past the recording and reproducing heads. This meant that the length of tape required for a half-hour's programme was nearly 3 kilometres!

Brief description of the ribbon or velocity microphone.

George Papandreou, Greek Prime Minister of the war-time government of National Unity in exile, is seen with the famous ribbon microphone developed by the B.B.C. in 1934. This microphone (R.C.A. designation 44BX) consists of a ribbon of corrugated aluminium foil only 0.0002 of an inch thick suspended vertically in a very intense but narrow magnetic field. When sounds vibrate the ribbon extremely low alternating

voltages are developed at the ends of the ribbon, which has a very low impedance of only 0.15 ohm, necessitating the use of a step-up transformer of 1:45 turns ratio very close to it. The frequency response is 20 to 16,000 Hz. A drawback is that the ribbon can be blown out of the magnetic gap by sudden puffs of air when a speaker gets too close to the microphone, so the casing is lined with several layers of chiffon which let in the sounds but not the air. Without its base the ribbon microphone weighs 4 kilograms, nearly 9 lbs.

An outstanding antenna system designed by Rex G4JUJ for Phase III
amateur satellite communication.

The up-link section comprises four 88-element Jaybeam multi- beams which provide a power gain of 225.

The two down-link 8 element yagis are each fitted with a small D.C. motor directly coupled to a 9 inch length of M5 brass studding rotating inside a block of PTFE linked to a push rod which can move the antennas

75 degrees both sides of the vertical position, either in unison or in opposite directions. This system provides infinitely variable polarisation which optimises the down-link signal at any instant.

The saga of H.H.M.S.ADRIAS

While fighting in the area of the Dodecanese Islands on the night of the 22nd October 1943 the destroyer ADRIAS (L67) was seriously damaged by a mine but refused to sink.

Under the command of Commander John Toumbas the ship covered a distance of approximately 700 nautical miles, reaching the port of Alexandria in Egypt on the eve of the feast of Saint Nicholas, the patron saint of all seamen.

The Greek Minister of the Navy Sofoclis Venizelos, and the British Admiral in command of the Royal Navy in the Eastern Mediterranean, provided an honorary escort for the brave little ship that had refused to die. A few months later the snub-nosed L67 joined the fleet of 100 vessels of all sorts which sailed to Greece for the Liberation.

The photographs were taken by the author (with the exception of the damaged L67) who travelled back to Greece on H.H.M.S. AVEROF in the

same convoy. The photograph of L84, a similar type destroyer to ADRIAS shows how much of her bows was blown off by the collision with the mine.

(H.H.M.S. stands for His Hellenic Majesty's Ship.)

German sabotage at the Cable & Wireless station at Pallini, Greece,
in World War II.

As the German army was pulling out of Greece in October 1944 its engineers carried out extensive sabotage to installations of a strategic value. At Pallini, not far from Athens, an attempt was made to destroy the transmitter hall by dropping one of the antenna towers onto it, but the equipment was not damaged.

They were more successful at the Royal Navy transmitting site at Votanikos. Here they tried to destroy six 300 foot tubular masts. One remained standing and also the lower part of another. All the test gear in the lab was thrown out of a second floor window and burnt. I was acting as official photographer for my unit at the time. When I walked into a small store room I saw all the equipment had been thrown off the shelves on to the floor, but appeared to be intact. I spotted a box of brand new packed German navy morse keys and decided the time had come for me to acquire a small war trophy of my own. As I bent down to pick up a key, I was horrified to see two large sticks of gelignite perched perilously on the edge of a shelf. The explosive was tied with white ribbon, with a weight attached to the other end. I froze to the spot. Gingerly I lifted my trophy out of the box and began to walk slowly backwards, being very careful not to knock anything over. I breathed a sigh of relief when I was out of the room and immediately alerted the engineers who came and defused the booby trap. So this book might never have been written thanks to the German army.

At the Athens broadcasting station transmitter site at Liosia my unit erected a small temporary 'T' antenna which allowed the station to come on the air again, but a short time later, when the ELAS guerrillas overran the area they began using the transmitter to broadcast their own view of events. We provided the broadcasting authority with a BC 610 mobile transmitter installed next to the Parliament building in the centre of town,

using the same frequency of 610 KHz. Listeners in Cairo couldn't understand what was going on when one moment they heard an official government announcement and a little later a war communique issued by the Communist guerrillas.

Over-the-horizon or Ionospheric HF Radar - OTHR

As mentioned briefly in Chapter 1, it was in April 1976 that the then Soviet Union first unleashed a diabolical noise on the HF bands which caused widespread interference to all broadcasting and telecommunication services between 6 and 20 MHz. On the first day the "knock-knock- knock" went on continuously for over ten hours. Radio amateurs, who were among the services that suffered from the interference, soon came to call this noise "the woodpecker". By rotating their beams when tuned to the 14 MHz band they established that the transmissions appeared to originate from the vicinity of the town of Gomel in the U.S.S.R.

The governments of many countries world-wide immediately protested to Moscow, and all they got in reply was a brief statement that the U.S.S.R. was carrying out "an experiment".

The reason for the very strong on/off pulses was probably because, at first, the Russians were using existing radar antennas which permit the transmitting and receiving functions to share the same antenna. Modern OTHR installations have different transmitting and receiving sites, often located many miles apart.

From the early 1950s pulsed oblique ionosphere sounders had shown that the normal ionosphere is much more stable than had previously been thought to be. The physical reason for this is that the incredibly tenuous ionized gas which does the reflecting has a molasses-like viscosity. Of course, there are daily and seasonal changes, but over limited periods of half an hour or so, the F layer at a given location is actually quite well- behaved. It bounces back signals in a nearly constant direction and with nearly constant amplitude -- just what is required for good radar performance.

Over-the-horizon HF radars use the ionosphere as a kind of mirror to "see" around the curvature of the earth. They have a variety of uses, both

military and civilian. And they have the advantage over line-of-sight microwave radars of being able to cover enormous areas with much less power and at a fraction of the cost of the latter.

A "relocatable" OTHR system can track aircraft targets right down to ground level. In an early experiment operators were puzzled by the sudden disappearance from their screen of an aircraft they had been tracking as it taxied along the ground. They found out later that the reason for the disappearance was that the aircraft had gone into a metal hangar which did not show on the screen because it was not in motion, as explained below.

In 1979 the United States Air Force began experimenting with an OTHR system at a site near Bangor, Maine. Because HF frequencies were being used the power was kept very low to minimize interference to other services during the early tests. At the time of writing (1989) it is believed that a full-power relocatable OTHR system situated in Virginia is being used in the anti-drug war.

As can be seen from the map this ROTHR can cover a vast area of

1.6 million nautical miles, straddling the whole Caribbean. The scan area stretches from the coast of Colombia in South America up through Nicaragua and Honduras to Florida (on its west boundary) and then southwards through Puerto Rico, to Trinidad & Tobago and the northern coast of Venezuela.

But this vast area is not covered continuously; the system operator can provide surveillance in a number of sectors known as DIRs (dwell information regions). Each one of the 176 DIRs can be "illuminated" for only a few seconds at a time. Small aircraft and small vessels can be detected by an ingenious method, only when they move. This is how it is done:

At the receiving site of the ROTHR system a very large antenna stretches out over a distance of 8,400 feet. It consists of 372 dual- monopole vertical elements each 19 feet high, backed by a huge reflector screen which makes the antenna substantially unidirectional. Each pair of vertical elements has its own receiver which digitizes the incoming signals. All the digitized signals are then fed through a fibre-optic link to a master signal processor. The main receiver can be programmed to pass on

"returns" from one particular region while eliminating most of the other returns as unwanted noise or clutter. But because the wanted target is moving, while the clutter is not, a filtering system based on the Doppler Shift principle (even when the echo is only one or two Hertz different) will lock on to it and track it as long as it stays in motion.

Futhermore, the ROTHR system has its own built-in automatic management & assessment function and does not have to depend on external sounding data. It measures the ionosphere height continuously and instantly selects the most appropriate frequency to use to scan the target area, ideally in one hop.

This automatic function uses a quasi-vertical incidence sounder (QVI) to measure the height of the ionosphere near the transmitting and receiving sites, which as mentioned earlier can be miles apart, and a radar backscatter sounder to measure the height of the ionosphere downrange 500 to 1,800 nautical miles away. The incoming real-time data from these soundings are compared with data stored in computer memory. Once real- time data are matched to a model of the ionosphere, the model can be used to operate the system for the best results, based on the prevailing propagation conditions. The data for the ionospheric models take up more than 200 megabytes of computer storage space. Operators thus know when and where to expect degraded performance. Of course, strong solar activity can virtually make over-the-horizon HF radar unusable.

A Spectrum Analyser display shows all the frequencies between 5 and 28 MHz. In order to avoid possible interference to other services, those frequencies which are known to be permanently allocated to fixed broadcasting and telecommunication stations are locked out, as well as frequencies which happen to be used at any instant so that they can also be avoided by the OTHR transmitter.

GLOSSARY for non-technical readers.

A.M. A mode of modulation (amplitude). A.R.R.L. Amateur Radio Relay League (U.S.A.). Beacon Transmitter radiating identification signal.

C.Q. General call, to any station. C.R.T. Cathode ray tube (like TV screen).

C.W. Continuous wave (mode of sending telegraphy). Callsign Station identification (letters & numbers). Coherer A device for making radio frequencies audible. DE Morse abbreviation for `from' (French). DX Communication over a long distance. Detector Any device for making radio frequencies audible. Doppler shift Change in pitch (of sound) or frequency of a (radio) wave E.D.E.S. Initials of a war-time Greek guerrilla organisation. E.E.R. Equivalent Greek initials for R.A.A.G. (q.v.) E.L.A.S. Initials of a war-time Greek guerrilla organisation. E.L.F. Extremely Low Frequency. E.M.E. Earth-moon-earth. Also Moonbounce q.v. H.H.M.S. His Hellenic Majesty's Ship. Gasfet A type of transistor. KHz Kilohertz - international unit for kilocycle. M.U.F. Maximum usable frequency. MHz Megahertz - international unit for megacycle. Moonbounce Communication by reflection from the moon. OTHR Over-the-horizon radar. Q code Abbreviations used when communicating by telegraphy. Q1 Unreadable. Q2 Barely readable - only some words. Q3 Readable with considerable difficulty. Q4 Readable with practically no difficulty. Q5 Perfectly readable. QRO High power. QRP Low power. QRT "Stop sending". Frequently used for "shut up". QSO Two-way communication. QST Call to all stations. Also title of journal of the A.R.R.L. QTH Location or address of a station. R.A.A.G. Radio Amateur Association of Greece. R.F. Radio frequency. R.S.G.B. Radio Society of Great Britain. RST System of reporting readability, strength & tone of a signal. RX Receiver. S unit Unit for reporting strength of received signal. S.I. unit International system of definitions. SSB Single side-band - a mode of modulation. SWL Room where radio equipment is set up. Shack Room where radio equipment is set up. Silent key Deceased radio amateur. Sporadic E. Propagation via the E layer of the ionosphere. T.E.P. Transequatorial propagation. TX Transmitter. Troposcatter Propagation via the troposphere. U.H.F. Ultra high frequency. V.H.F. Very high frequency.

W.A.C. Worked (contacted) all continents. XYL Wife of a radio amateur. YL Young lady operator. 73 Morse abbreviation for ``best regards''. Yagi A type of antenna designed by a Japanese of that name.