Download The Grimeton VLF Transmitter SAQ

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!