4. 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.
5. 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.
6. 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.