Amateur Radio or HAM radio is a device most of the people from law enforcement are familiar with. They are the handheld or car mounted devices used by police to communicate using radio waves. They are different from the radios common people use. Common people use Citizen Band radios which do not require any special license while HAM radios use Restricted band and in most of the countries require a licensing for that. Amateur Radios usually don’t use frequency bands like AM or FM.
As HAM radios don’t rely on any pre-established communication grid, it is more reliable than telephone networks or the internet, and even digital data packets can be sent over high frequency bands. The messages are sent either by voice or International Morse Code.
The community grew after Guglielmo Marconi successfully sent the first trans-atlantic wireless signal in 1901. At present there are over 16,000 licensed users in India.
But as HAM radio spectrum is mostly used for disaster management and other official purposes, transmitting random data to a frequency band without proper knowledge can wreck havoc. A proper training and licensing is required to be able to use a HAM radio. There are radio clubs that can train radio enthusiasts how to use a device. The International Telecommunication Union placed India in ITU region 3, this region divided into two zones. Each licensed owner gets their own identity also known as “call-sign” depending on the zone they are in which they can use to communicate with other licensed owners. In some cases licensed owners need to verify their “call sign” every 10 minutes. Nowadays the call-signs start with VU and this system was introduced in 1929.
There are two types of license an enthusiast can apply for known as:
- Amateur Wireless Telegraph Station Licence (GENERAL), and
- Amateur Wireless Telegraph Station Licence, (RESTRICTED)
General grade license holders have a call-sign prefix “VU2”, and the Restricted grade holders have a call-sign prefix “VU3”. Foreigners operating in India also get this prefix in their call-sign. The latter part of the call-sign only contains letters, so a complete call-sign looks like “VU2ABC” or VU3XY”.
In India, The Union territory of Andaman and Nicobar Islands are assigned VU4 and Lakshadweep is assigned VU7. During special events or contests temporary call-signs are allotted.
Transmitting signals without a license and call-sign to the frequency bands that has been reserved for ham users is illegal and punishable with fine. But listening to any radio band is not an offense.
HAM, and other Radio Frequencies are also a part of Open Source Intelligence known as Signal Intelligence or SIGINT.
For Wikipedia entry on HAM Radio, click here.
For more posts on Computer basics, click here.
For more posts in The Cyber Cops project, click here.