Wednesday, February 29, 2012

BBC World Service at 80


The BBC World Service - which marks its 80th birthday today, Wednesday - was broadcast only on shortwave back in 1932. Today, audiences on FM, digital radio and the internet are growing fast while shortwave is in decline, but for millions it remains a lifeline.



Shortwave listeners catch a signal that travels thousands of miles across international boundaries, sometimes eluding censors, by bouncing off the turbulent gases of the ionosphere, the layers of electrified gas several hundred kilometres above the earth.



It's a signal that can be capricious - subject to interference from electrical storms and other atmospheric disturbances and, mysteriously, often best at sunrise or sunset.



But even when heard against a background of electronic warbling, whistling and hissing, shortwave has reliably delivered the news for 80 years.
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Robert Mulvaney, glaciologist, Antarctic

I am a glaciologist studying climate change who works "in the field" in Antarctica. This means living in a tent for up to 80 days at a time.



In the past, I used to cut out the daily World Service programme schedules for one week from the newspaper in the UK, and stick them into the back of my diary, then use this as a guide. Generally I would listen in the evenings after we had finished work for the day.



We live, sleep and cook in pyramid tents, two people in each tent. My routine was often to sit in the tent cooking on the Primus paraffin stove, and listening to the BBC World Service with headphones on, occasionally removing them to talk to my colleague.



The best time for listening was when I would get in my sleeping bag (for warmth) and listen to the radio until it was time to sleep.



In some seasons, we have periods when the weather is too bad to work outside - we call this a "lie-up" - and you may be confined to the tent for a few days. Then I would try to listen to the BBC World Service during the day, but the reception was never quite as good as in the evening - I guess it is the structure of the ionosphere, with a more perfect radio reflector during the evening.
How can I improve my reception?


When it's not good, I get the range of interferences from slight hissing to the reception strength varying within minutes from strong to weak to strong again. Occasionally we used to get a woodpecker sound overlain on the radio signal - a rapid rhythmic tapping that starts loud and fades.
I always used an extension aerial. Generally, I lay out a long-wire aerial for my Sony radio, which has an extension aerial socket.

The way we do this with the pyramid tents for both the communications radio and my Sony is feed a wire out through the ventilation "dongle" in the apex of the tent, and keep the wire clear of the ground by suspending between bamboo poles.




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