When broadcasting started, around 1920, it used quite long wavelengths: 1000 to 3000 meters was not unusual.
Still, the French name for Medium Wave is Petites Ondes, or small waves.
The first long distance connections were made also with extremely long waves.
For example, in 1925 Sweden opened the Grimeton station to operate with the United States at a frequency of 17.2 kHz,
and the Netherlands had its Kootwijk station to work with Indonesia.
The reasons were the difficulty in constructing high frequency amplifiers,
and the belief that shorter waves were not suitable for maintaining stable connections.
However, in the early nineteen twenties, radio amateurs discovered that large distances could be reached with waves as short as a hundred, and even ten meters. They also discovered that propagation varied a lot over the day and over the year, and was dependent on weather conditions, too. So a bit of planning was necessary, but then a lot was possible with limitied investment in power and installations. A big advantage of short waves is that antennas are also shorter (proportially) and thus easier to set up and maintain.
During the nineteen thirties, shortwave was introduced in the living room.
As of the early thirties, shortwave sets were available (Erres KY137, Philips 2802), but they were an exception rather than the rule:
the first generation of factory receivers, say up to this CeBe set of around 1936, was equiped with medium and long waves.
Construction shortwave sets became easier with the introduction of better (more stable) mixer tubes, like the AK1 and AK2.
Indeed, on later sets, like this French B.F.R., one would often find a shortwave band, covering wavelengths of approximately 16 to 50 meters.
In 1940, the loctal tube series was introduced, and its flat glass bottom with feed-through pins allowed cheap tube construction with very small tolerances.
From that time, shortwave was also found on low budget sets, like the Philips 208U.
So, we can say that a shortwave band was found on most home receivers from about 1940, to about 1970.
Around 1970, the shortwave band disappeared again from the living room.
The classical principle of a radio was left behind, in favour of stereo installations, of which the tuner system emphasized FM reception, but usually included Medium and Long Wave reception of limited quality.
How can the hype of shortwave reception around 1950 be explained? I think the second world war had made more people conscious that a world outside their own county existed, so they wanted to learn about international affairs by hearing the transmissions of those countries. Indeed, a lot of interesting programs of good quality were made by many countries, and it was very nice to study a culture by hearing its radio shows.
Second, there was a lot of emmigration, for example to Canada and Australia, following the depressing war years.
This caused more people to be interested in hearing these foreign transmissions, but also,
the emmigrants wanted to keep in touch with their former home countries by shortwave.
Especially for them, Philips kept a line of Emigrant radios (see flyer right);
remember to recognize them quickly by a 5 as the third digit in the type number!
I must say that the emigrant sets differed from sets for The Netherlands in more respects.
Of course, they had at least several short wave bands, but these bands often included the tropical band (60-180 meters) that was hardly used in Europe, and lacked the Long Wave band (800-200m) that was only used in Europe.
The power supply sometimes included the possibility for battery supply (see the BX505 in the list on the left),
or main voltages like 90V or 145V.
Finally, the sets were tropicalized by having extre moist protection around the IF coils and other sensitive parts.
Another explanation may be found in the 11-year sunspot cycles.
Shortwave propagation is much dependent on atmospherical conditions, and when there are many sun spots, propagation is better.
By a still not understood mechanism, sunspot activity fluctuates in an 11-year period (see graph), and there was a multi-year peak from 1947 to 1949.
This means that in those years, reception of remote stations was very good in general, and perhaps people (and factories!) exploited this peak with extra shortwave capabilities.
Of course, it is a bit disappointing if you buy such a set for a lot of money, and after a few years you notice that you can receive less and less stations!
Technical aspects
In all but a few cases, the shortwave capabilities were limited to having extra bandspread.
Sets with a single shortwave band are tremendously difficult to tune.
Compare with the Medium Wave, which ranges from 530 to 1610 kHz, a range of 1080kHz wide filled with stations spaced 9kHz: the spacing between channels is about 1/120 of the entire dial.
Short wave ranges differ, but a coverage from 6 to 18 MHz is often found, which is a 12,000kHz band filled with stations spaced 5kHz; the spacing is 1/2400 of the dial.
Having bandspread means that the coverage of the enormous range of shortwave frequencies is split over multible bands, to make it easier to tune to stations and to find them back later.
The Philips sets below cover the entire shortwave range, but split over four to six bands; still, each of these bands covers several MHz. The Pye and EAK sets have a further improvement: their shortwave bands together do not cover the entire shortwave range, but just those parts that are used for broadcast stations. This choice allows the shortwave bands to be as narrow as 500 to 900 kHz, making tuning as easy as tuning a Medium Wave radio.
Ideal shortwave receivers should have narrower Intermediate Frequency bandwidth, because channel spacing on shortwave is only 5kHz, while it is 9kHz on Medium and Long wave (10kHz outside Europe). Also, to suppress mirror frequencies, a RadioFrequent pre-amplification would be required, or perhaps even double conversion. Indeed, a professional receiver like the Siemens E566 (right) has such features, but the radios discussed in this article generally lack them.
| Description | Type (Sound) |
|---|---|
 |
Zenith TransOceanic 1947 PLAY |
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Philips BX480A 1948 PLAY |
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Pye T19D 1949 PLAY |
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Philips BX591A 1949 |
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Philips BX690A 1949 |
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Philips BX594A 1949 |
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Philips BX505AV 1950 |
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EAK 6450 1952 |
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Philips BX998A 1955 PLAY |
 |
Pye P445 1960 |
The Zenith is not truely a home radio; it was targeted to travellers, seamen, and soldiers. It is a battery set for portable use. The Zenith does have a RF pre-amplification stage, and seperate antennas for shortwave.
The Philips BX480A, BX591A, BX594A, and BX690A are what I call typical home shortwave sets.
They are plain four-stage sets: that is mixer, IF stage, AF preamp, output.
Electrically they were almost the same, and they had the same dial (right).
The cheaper variant (luxory class 4) had a bakelite cabinet and no tuning eye, and the luxory class 5 variants had a wood cabinet and EM34 tuning indicator.
The luxory class 6 one, BX690A, has a total of eight bands and a very cute dial that shifts upwards when the bands are changed.
It has a wood cabinet, of course, and push-pull output.
The BX505AV is an export set, with the possibility of battery supply, and the tropical band.
The list mentions two models from England: Pye T19D and P445.
The first one is an eight band good quality home set; the second one an ACDC set of 1960.
Perhaps Pye wanted to exploit the sunspot peak of 1958 with a cheaper model directed to DX-ers.
| Description | Type (Sound) |
|---|---|
 |
Philips 22RL798 1969 |
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General TF161 1969 |
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Barlow-Wadley XCR30 1973 |
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Satellit 2000 1973 PLAY |
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Marc NR-52F1 1975 |
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Tokyo Panda 1975 |
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VEF 202 1975 PLAY |
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SuperSound 1975 PLAY |
These sets came with extras like the Police or Air band, suggesting the possibility to receive very exotic and perhaps even secret communications, follow the Police in gangster hunts, etcetera. What counted for these radios in the first place, was the number of bands that could be advertised on the box. For this reason, bands were often split: On the SuperSound radio, for example, there is electrically spoken just one MW band, but on the dial it is split into a broadcast band and a sport band. In that way, this five band radio could be sold as a nine band one.
A world map and time conversion dial would complete the illusion that the buyer of this radio was ready to receive broadcasts day and night from all over the world. The chrome on these models was usually fake (painted plastic).
Philips set a quite bad example with its L6X38T of 1963, a model later renumbered to 22RL798. I must say to its defense, that FM reception of this radio is superb. But it has four shortwave bands, and shortwave reception is quite disasterous.
About the Barlow-Wadley there is also a good thing to say: it has an absolutely unbelievable dial precision, achieved by implementation of Barlow's triple conversion drift cancellation circuit. Unfortunately, you receive more noise and mixing products with it than foreign radio stations.
The VEF is actually a quite good radio, and I had three of these sets over the years. It is the best receiving radio in this overview, and notice the lack of time converter and world map!
The Marc was truely a band champion, with 12 bands reaching from Long Wave to UHF (430MHz, I used to listen to car phones).