Once again SAQ, the wonderful old radio station at Grimeton, Sweden, was on the air with a Christmas Eve broadcast. This rig is the predecessor of all of our modern CW rigs, producing clean high-power CW signals back in 1924, long before vacuum tubes were up to the job.
Unlike the damped waves of the spark transmitters in common use then, SAQ produced a clean CW signal using a huge motor-generator. That worked very well, but the mechanical limits of a generator to produce high frequencies for use in radio transmissions limited the upper transmitter frequency to about 20 kHz (0.020 MHz!). Grimeton operates as a frequency of 17.2 kHz. Pictures of the facility, the transmitter and the antenna are available here: http://www.alexander.n.se/ Propagation at those frequencies is pretty much independent of ionospheric conditions but getting an efficient antenna up is a bit of a challenge. After all, at that frequency a quarter wave wire is over 5 miles (8 km) long! Clearly, in spite of their huge installation, they suffered with limited antenna efficiencies as badly as any Ham today who lives with stealth or indoor antennas on HF, but their transmitter did put out a signal that reached across the Atlantic. The station has been preserved and the old transmitter is put on the air for special events such the annual Christmas transmission. Since few of us are equipped to receive signals at 17.2 kHz (not even the K3 tunes that low), noted low frequency enthusiast Jay Rusgrove, W1VD, has placed on his WEB site snips of this year's transmissions received across the Atlantic ocean in New England. You can hear SAQ signing their call in this one:. http://www.w1vd.com/SAQ122407A1B.wav For all the 'phone enthusiasts, it was a similar transmitter that was used to provide the first tests of an AM phone signal. AM is easily received on simple diode detectors such as those in common use on the high seas to receive spark Morse transmissions. In 1906, 18 years before the Gimedon transmitter was put on the air, Reginald Fessenden made a voice broadcast on the frequencies in common use by shipboard operators talking, playing his violin and in general startling listeners who had heard nothing but Morse in their receivers! Some recordings of Fessenden's early transmissions (done on wax Edison cylinders) available on line at http://www.hello-radio.org/historyofradio.html I hope for all of us who enjoy communicating by wireless more of the sort of excitement that all Hams have experienced since Marconi himself proudly called himself the "First Radio Amateur". Ron AC7AC _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
