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The Grimeton VLF Transmitter SAQ At Grimeton, Varberg, Sweden Right Place, Right Time • In 2009, Andrée & I were touring in Sweden. • Bosse SM6YEB had warned me that the 85 years old Ultra Long Wave station SAQ was going to be started end of August • It so happened that we were on the West Coast and could visit! Not your every day Ham Station Pre-Electronics Station • Using a Motor-Generator (M-G) set for the radio power; no tubes, no transistors, just rotating equipment! • From far away, one can see 6- colossal steel towers, 127 m high with 46 m booms • They support 8- wires, 2.2 km long, insulated like a high voltage power line Antenna M-G Set M-G Set M-G Set details • Motor 440 kW, 3-phase 2300V, 50 Hz, ~711 RPM (adjustable), 8 poles • Speed Increaser (gear box) ~1:3 ratio • Alexander alternator 200 kW, single phase, ~17.2 kHz, ~2133 RPM, 976 poles • Weight ~50 tonnes Speed Increaser Schematics Schematics • Reduced voltage starting • “VFO” by rotor resistance adjustment • Output is shorted at “0”, i.e. between Dahs or Dits Schematics • To maintain speed (frequency), the key controls: • A) Motor stator voltage • B) Decrease in total rotor resistance • Antenna tuner to 20 ohm, ~600 A Antenna details • 8- 2.2 km long wires used as a grid for a common “top hat” capacitance (0.05 microF?)(120 kV?) • At each tower, a vertical antenna element, top fed & bottom loaded/tuned (~10 mH) • These verticals (spaced 380 m) fire a “broad-side” to Long Island, N.Y. Feed-point of antenna Network of Alexander Stations Receiving station • Was located ~200 km North at Kungsbacka • 13.4 km long Beverage antenna, 2 wire, 9 m above ground • Suitable for 26.1 to 17.2 kHz (11.5 to 17.4 km wavelength) • Station was not visited & does no longer exist. Receiving station (Swedish) Partial Control Panel Traffic 1924-1950s • Start-up 30-Nov-1924, used till 1950s • “Handled 95 % of all telegrams to North & South America” • Capable of 100- 5-letter words per min. from paper tape • Normally, operating speed limited to 50 words/min. Traffic 1960s to 1996 • From 60s to 1996, it transmitted commands to Swedish submarines. • In 1968, a 2nd tube/transistor transmitter was installed for submarine use • The Alexander transmitter went out of service 1996 & was declared a national monument “Varberg Radio Station” • The station is a Museum that can be visited in the summer • The Alexander alternator and multiple tuned antennas is the only such installation remaining in the World • On 2-July-2004, the station was declared a World Cultural Heritage site by UNESCO (“Varberg Radio Station”, ref. 1134) Traffic to-day • Since the antenna is used for submarines, the Alexander transmitter is rarely operated with the antenna (once or twice per year). • Refer to www.alexander.n.se for operation • Station will QSL ! Traffic to-day Recommended reading • www.grimeton.org • www.alexander.n.se • Or just search for “saq grimeton”, etc. • Thank you!