| In the late 20s and early 30s the listening public were being made aware of broadcasting from outside their immediate neighbourhood. In the early days, especially with crystal sets comfortable listening range was severely limited to local stations only 15 to 20 miles away, but as wireless sets became more advanced, particularly with better valve performance, more and more stations came within the range of one's loudspeaker.With the realisation by the authorities that radio could span the world, given the right choice of operating frequency, and the construction of high power stations all over the globe, short waves became the mecca for dx enthusiasts. |
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Larger pictures, see below... In the early days it had been (just) possible to hear stations from across the Atlantic, but as the number and power of European broadcasting stations grew, listening to really remote stations got more and more difficult in the band 500 to 200 metres. Once long distance broadcasting using short waves became established, and the public began to hear about such things through their radio magazines, they got interested in listening to far-off stations. In the early 30s some sets included a real short wave band. Prior to this the bands had indeed been christened "Long" and "Short", but now with the use of new wavelengths below 100 meters the terms were re-defined and what were "Short" waves became "Medium" waves. Short waves were now classed as the range of wavelengths from 10 metres to 150 meters. The vagaries of the various layers of the upper atmosphere, when charged by the sun's rays, helped define new broadcasting bands such as the "40 metre band" and by the mid 30s all-wave sets displayed these new bands on their dials, together with a selection of the most popular stations operating within them. What if your wireless didn't have the facility to tune in to these new wavelengths? One solution was the Eelex short wave converter, but mostly people just junked the old TRF set and bought a nice new all-wave superhet. The design of the superhet made short wave listening ever so much easier than using an old TRF set, with its multitude of interactive controls... not to mention hand capacity effects, if the front panel was wood or ebonite. The Eeelex converter therefore had a limited lifespan and was really the poor man's choice compared with a new all-wave superhet. Some really adventurous manufacturers and kit designers even went as far as introducing the public to ultra-short waves. In the early 30s experimental transmissions were getting underway to broadcast high definition television, not only in the UK, but also in Germany for example, and one or two designers included provision for listening in to the sound channel of such stations.The Eelex models added tuning capabilities to a standard long/medium receiver taking it down below the lowest medium wavelength of 190 meters right down to 16 metres. |
