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!