SP8WJT/HF8V - RED ARMY RADIOTELEGRAPH SIMULATOR - SP8WJT/HF8V AERO STATIONS ver. 4.29 OVERVIEW: Radiotelegraphy's career in aero services was short but very fierce. I think its peak was at 1930's and would be also in 40's but war in Europe little bit suppressed it. There was more Aero stations than Coastal staions and in some period and there was almost the same count of ground aerological stations as aircrafts itself! Many smallest aerodromes needed communication, a lot of them were situated in remote areas without any landline telecommunication services. Ground radio was crucial for flying. Unlike Coastal stations, Aero stations was much smaller one, often manned by one or two radiooperator. There was big technical problems during 1920s to implement radio in aircafts. Noise generated by motors was so strong that radiooperator could hear nothing in his receiver and vibrations was so strong that there was real problems to build stable tube oscillator for short wave bands. Thats why LF and MF CW was basic form of aero communication and HF CW was added only in 1930s. LF and MF has local ranges similiar to VHF today and it was also impossible to shift all these stations to HF. Radiotelegraphy was used everywhere in Europe, while in North America they shifted to fone already in 1930s (thats why you can hear many undefined fone signals in LF and MF band in RARS! Usually it was their assignements). AERO MF BAND It was basic band at that time. All bigger (passenger, flying boats etc) aircafts for international flights were fitted with MF CW and it was standard. QCY (trailing) antenna was used. It would be 60 or 80 metres of wire, but radiooperator would use shorter length for more local QSOs. Transmitter power of some 50W was adequate. Ranges of some 400 km (250 miles). BANDPLAN in late 1930s, early 1940s =============================================================================== kHz SERVICE =============================================================================== 320-350 Aeronautical radiotelegraphy band 322 Aircraft frequency (also for traffic control) 327 DF frequency 330 Ground stations for aicraft in flight 333 International calling and distress frequency 336 Calling and working for ground stations (without assignment) 336 DF frequency 338 Ground stations for aicraft in flight 340 Ground stations for aicraft in flight 342 Ground stations for aicraft in flight 343 Ground stations for aicraft in flight 344 Ground stations for aicraft in flight 348 Radiocommunication with small aicrafts 350-365 NDB radiobeacons =============================================================================== At that time above 365 kHz was oridinary coastal band. There was small amendements in this bandplan later and finally whole band was "consumed" by NDBs... SIMULATION: Many various networks and procedures were simulated. In 1930s many things were not standarized yet (even international organisations like ICAO was established later), there was many various procedures and standards. Nazi Germany for exampe at that time established very roboust radio communication system and this is very nice described here: [1]. Anglo-americans has its own procedures, etc. Thats why this subject is far from completness yet, although many interesting things are in the air already. Thanks to excellent Frank W. Fischer book, all German stations are on the air on their original QSW and QSX frequencies. I can only dream about such material about other countries... Features simulated: - International calling frequency 333 kHz - Aviation Meteo (various procedures and codes) - Australian aircaft traffic - Australian ground traffic - German ground and aircaft traffic - British Flying Boats - German Flying Boats - Aero QTE - Old Aero QTE - Australian QTE freq - Aeroflot - Russian Distress Frequncies (SOS message) Zeppelins are already on theirs original frequncies but not much traffic yet, although I found original radiotelegrams in the net so it will be linked to this traffic soon. SOURCES: [1] Die Flugsicherung in Deutchland vor 1945: Ein Rueckblick: Teil 1, Frank W. Fischer REMARKS: If you can help with aero traffic please email me, this subject is escpecially very difficult because many orignal materials were lost.