Many radio amateurs who became interested in radio after WWII cut their teeth on and
learnt a great deal from the enormous amount of war surplus gear that was available very
cheaply. On the whole it was simple, big, and easily modifiable, and gave excellent
results. It was usually beautifully engineered, too, and would withstand considerable
abuse with the soldering iron or, as was the case with one of my 19 sets, from having been
dropped in the sea.
Notational note:
In the decades following the 1940's, which is when these
sets were in general military use, frequencies were given in megacycles/sec, Mc/s; these
are the same as MHz, and to preserve the period flavour I have used Mc/s here. Further,
transmitters were called 'senders', and that too I have adopted. Some of the pages are
written as nearly as possible in the original layout; others I have modernised somewhat,
particularly regarding fonts.
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- CW = continuous wave, i.e. Morse code telegraphy;
- MCW = modulated continuous wave. This technique puts a tone
on the CW, and can be received by sets which cannot ordinarily receive CW because they do
not have the local oscillator needed to make CW signals audible;
- RT or R/T = radiotelephony, i.e. speech.
- FM = frequency modulation.
- superhet = superheterodyne. This technique converts all
incoming signals to the same frequency - around 455 kHz is common for short-wave radios -
because it is easier to control the selectivity (i.e. ability to reject adjacent signals)
and gain in fixed-frequency amplifiers. Double superhets use two conversions; receivers
such as the Racal RA17 used 40 MHz and 455 kHz; others used 455 kHz and either 100 kHz or
85 kHz.
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The sets:
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- R107 receiver: 1.2 - 17.5 Mc/s, 3 bands, 9
valve superhet
- R209 receiver: 1-20 Mc/s, 3 bands; 10-valve miniature superhet,
hermetically sealed.
- Wireless set No. 19: AFV sender-receiver: 'A'
set 2 - 8 Mc/sin two overlapping bands, CW/MCW/RT; 'B' set 235 Mc/s RT only; intercom
amplifier for intra-tank communication.
- Wireless set No. 31: portable sender-receiver,
41 channels 40 - 48 Mc/s, FM, double superhet.
- Wireless set No. 46: portable sender-receiver,
MCW/RT, 3.6 - 4.3 Mc/s, 5.0 - 6.0 Mc/s, 6.4 - 7.6 Mc/s, 7.9 - 9.1 Mc/s using plug-in
coils.
- Wireless set No. 52: sender-receiver, 1.75 - 16
Mc/s in 3 overlapping bands; CW/MCW/RT, 10-valve superhet.
- Wireless set No. 62: sender-receiver, 1.6 - 10
Mc/s, CW/RT. Although not hermetically sealed, this set could stand immersion in water for
5 minutes, and would float together with 20 lb extra load!
- Wireless set No. 88: portable sender-receiver.
Two varieties, 38 - 40 Mc/s and 40 - 43Mc/s, each having four channels. FM.
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Links:
There are numerous sites having the same
theme, to some of which I owe a considerable debt. I have especially appreciated
Louis Meulstee's wonderful offerings on 'Wireless for the Warrior'; visit his Home Page or his Links Page.
Radio pages contents
Home page
Rod Beavon 17 Dean's Yard
London SW1P 3PB
e-mail: rod.beavon@clara.net
