AIRCRAFT RADIO COMMUNICATIONS

Bay of Plenty Times, Volume LXXVII, Issue 14823, 10 November 1948, Page 5

AIRCRAFT RADIO COMMUNICATIONS

BRITISH EXHIBITION SHOWS DEVELOPMENTS MAINTAINING SERVICE IN BAD WEATHER The rapid expansion of air traffic and the desire to maintain the service with regularity in spite of difficulties arising from weather or climatic conditions is making increasing demands on radio communications.

It ccntinues to be one of the major problems confronting civil aviation at the present time, but the magnificent achievements with the “air lift” to Berlin has clearly demonstrated how the traffic handling capacity of airports can be stepped up to surprising proportions by the adoption of radio control. There have been important developments in radar and radio equipments and the S.B.AiC. display will afford an opportunity to view some of the latest instruments that have been evolved for use on or in connection with aircraft. On one stand it is anticipated that there will be one cf the new miniature light-weight Gee airborne receivei’s with its small and compact indicator for mounting in the cockpit. Model Shows How From many points of view probably the most popular exhibit will be a model to scale of a Gee ground station, showing transmitters, receivers and aerial arrays, while the explanations to be given of the new and revolutionary Gee track system, providing for the extension of cover to lower traffic densities must prove exceptionally interesting. Other equipment to be shown includes the V.H.F. transmitter-re-ceiver—a four “channel” crystalcontrolled aircraft set with an output of 6-7 watts in the 100-124 mc/s bands. , There will also be the general purpose H.F. communication transmitter providing 300 watts for continuous wave, modulated continuous wave, or radio telephony in the 1 5 to 20 m/cs bands. The items to be exhibited include a Redifon medium wave transmitter for telegraphy and telephony radio communication in the medium frequency aviation band, and suitable for ground-to-air, or point-to-point, communication or as a radio beacon, a special feature being the reduc-

tion of radiation from the oscillator during the “key-up” position. News Network The receivers include the one adapted for long periods of ccntinuous oneration under all conditions and‘useful for meteorological services and aviation information networks. Visitors will be able to tiv it for ihemselves. The Redifon GR.49 radio telephone is a complete out-and-in station claimed to be as simple to operate as an ordinary dial telephone, giving it advantages for approach control, even in small airfields. , The carrier power of oO watts is sufficient to provide good communications on ranges up to 150 miles or more, while any of five crystalcontrolled spot frequencies can be selected on both transmitter and receiver by a single switch. Alternative power units from A.C. to D.C. ,sources are available. The use ol a moving coil microphone ensures clarity of speech.