1942: La radio di fortuna dei prigionieri di Changi

Cory Doctorow, mitico blogger di BoingBoing riprende una citazione dal blog della rivista Make, "technology on your time", che a sua volta punta a un link scovato su un sito radioamatoriale dedicato al QRP, l'arte di trasmettere segnali a bassissima potenza. Si tratta della storia di come i prigionieri di guerra del campo di Changi, sulla penisola di Singapore (allestito dagli inglesi ma successivamente caduto in mano ai giapponesi che vi rinchiusero centinaia di militari), riuscirono a costruirsi un ricevitore a onde corte per seguire i programmi della BBC e della VOA.
La storia, scrive Doctorow, ricorda molto le vicende narrate dallo scrittore James Clavell, un britannico nato in australia, naturalizzato americano e scomparso nel 1994 in Svizzera, nel suo romanzo King Rat (tradotto in Italia col titolo di Qualcuno da odiare). Clavell è noto per la sua collaborazione con il mondo del cinema e della tv, sua fu la sceneggiatura di film La grande fuga, con Steve McQueen.
Nel campo di Changi furono imprigionati durante la guerra anche il matematico Alexander Oppenheim (che si ispirò alla sua esperienza pubblicando "The prisoner's walk: an exercise in number theory" e il fumettista Ronald Searle. Il racconto di come venne costruita la radio deriva da una intervista al tenente colonnello R. G. Wells. Il sito che ospita questo ricordo è curato da Thom Lacosta K3HRN e reca il motto latino Vi minore, plus gaudium. Grazie credo a Francesco per la segnalazione da BoingBoing.

Construction of Radio Equipment in a Japanese POW Camp

By Lieutenant Colonel R. G. Wells

Transcript of a recording by Lieutenant Colonel R G Wells, on the construction of radio equipment whilst in a Japanese Prisoner of War camp after the fall of Singapore.

It was about the beginning of 1942 when I was a prisoner of war of the Japanese, when I was ordered to go on a working party which eventually finished up in the Sankakan in British North Borneo. Two thousand odd of us were in this work party and it wasn't long before we noticed the absence of information as to the international situation, what was happening in the outside world, and the whole camp had a real craving to get news by whatever means. Escape parties were being organised, but none of these were very successful. The next thing people turned to was a means of getting some radio news, and this is where the building of a radio set became an urgent requirement.
The main thing, of course, was that we didn't have any components and although we had some contacts outside which later on were helpful in the building of this receiver, it limited our requirement to a regenerative receiver as from a super heterodyne receiver and the decision to do that was borne out by the results.
The high frequency spectrum during that time of the war was fairly quiet in that part of the world and the BBC, we hoped, would be able to be received. This was aided by the fact that the Japanese in their wisdom called a friend of mine out one evening to repair their radio set and he took the opportunity, of course, to switch over to the short wave bands, with headphones while doing that, and picked up the BBC successfully.
That day was memorable because it was the day that the BBC broadcast the death of the Duke of Kent in an aircraft crash. That was the only news we had of the outside world for something like six months.
The plan was made to begin building the radio, so until we could build components, there was nothing much we could do. A look at the circuit diagram of a regenerative receiver indicates a number of capacitors - about two or three are required -low capacitors to make the oscillating part of the system work, and in fact from memory we needed in the grid circuit at least one ".01 microfarad" capacitor and there was no chance we could get this anywhere, or any other components.
(continua)