| Kalpana Chawla: Hams to the fore
From 10 to 10.30 every night, the 250-odd hams, members of the Calcutta VHF (very high frequency) Amateur Radio Society, get together to catch up on news and gossip, and to chat about “everything under the sun, from Sachin’s batting brilliance to the condition and propagation of VHF, UHF (ultra high frequency) and HF (high frequency) in the city and the suburbs, as well as the weather”.
This VHF Ham Net rendezvous is not restricted to the boundaries of Bengal, however. Anyone around the world, with access to a ham radio, is welcome to join in the tête-à-tête.
On the megahertz (MHz) bandwidth, the wave frequency from 144 to 146 is dedicated to ham usage, courtesy the International Telecommunication Body, an arm of the United Nations that regulates frequency use. Hence, there are restricted bandwidths for the army, fire brigade and ambulance services, off limits for casual users. Now, Calcutta hams have been given a time and space — 145.200 MHz — to tune in together.
After passing the Association of Amateur Station Operator Certificate exam, conducted by the Central ministry of communication, in order to get a licence, a ham radio is all you need to set up shop for non-commercial use. “An imported set costs about Rs 10,000 to Rs 12,000. Nowadays, they are available here. You can build one, too,” says Arya Ghosh, secretary of the Society.
Part of the Society’s functions includes helping out in emergency situations, like medical problems. Hams were the lifeblood of aid and communication during the cyclone in Orissa in 1999, when all other means of contacting the outside world were cut off. Now, most emergencies can be handled by ham radio operators manning the newly-set-up VHF Net.
At the moment, the Society is in the process of trying to get the ‘pass’ timings of different Orbiting Satellites Carrying Amateur Radio (OSCAR). The satellites, launched over the years by space programmes in countries like France and Russia, orbit the earth and are regulated by agencies like National Aeronautics and Space Agency (Nasa).
“For instance, if one such satellite containing a ham radio passes over India and its neighbours, hams in these countries can talk to each other easily, through the HF, which is best for long-distance communication. That’s why we want to know the timings of when each of these satellites pass over our part of the world,” explains Ghosh.
The relationship between Nasa and hams goes back to 20 years, when, in 1983, an American astronaut, who was also an amateur ham, went up in space and contacted his fellow-hams on a VHF radio.
“Ever since, several space agencies have sent up hams to experiment in space. Even during the crisis on Mir, the international space station, when communication broke down, they used ham radios to get in touch with ground control. Kalpana Chawla, too, was an amateur ham,” says Ghosh.
Also on the Society’s agenda is installing repeaters. “They act as relay stations. When communicating long-distance, tall buildings are obstructions. But installing a repeater on top of them solves the problem. We are constructing one at the moment, and, hopefully, we will be able to accomplish our aims,” Ghosh signs off.