Benefits of Two-Way Radios

16/04/2008

Two-Way Radio - An Appreciation

The science behind two-way radios is now well over 100 years old and yet this groundbreaking technology remains central to modern day life. Two-way radios or ‘walkie talkies’ are employed to improve efficiency and effectiveness across a disparate array of industries - from taxi, courier and logistics operations, through policing and security, maritime and aviation and even in schools. So how did two-way radio come about - and what has it and does it achieve?

The mission for transmission

In viewing the history of two way radio, most commentators cite the key milestone as the first transatlantic telegraphic communication in 1907 by the National Electric Signalling Company. But you need to go still further back in time to discover the true technological genesis. In 1888 one Heinrich Hertz showed it was possible to transmit and receive electrical waves without wires. Genius as he was Hertz failed to recognise the practical importance of his great discovery (although his historical consolation was Hertz being named as the unit of frequency) which successive pioneers latched on to or supported through creation of complementary technologies.

A crucial figure was Swedish boffin Ernst Alexanderson who enabled speech transmission by creating the first high frequency generator - an alternator which produced a continuous wave carrier capable of hosting voice communication. He did so at the request of Professor Reginald Fessenden, a former employee of one Thomas Edison who pioneered the combination of sound and radio carrier waves. It was Fessenden whose National Electric Signalling Company made the first, historic long-range voice transmission using a 2kw, 100khz high frequency Alexanderson Alternator.

Walking the talk

The genie was now out of the bottle and applications for this new two-way radio technology were soon found. Radio transmitters and receivers were installed on ships so that by 1912 mariners could benefit from two-way communication. Indeed it is argued that the hundreds that survived the Titanic disaster that year had Gugliemo Marconi to thank - his radio equipment enabled far swifter emergency communication than the old carrier pigeon method! But the invention of the first mobile two-way radio can be credited to an Australian policeman, Frederick William Downie, who introduced sets to Victoria state’s patrol cars in 1923. This was mobile radio, 1920’s style though with the huge sets taking up all the back seats! Depending upon your historical perspective the first genuine’walkie talkies’ were either invented by the Canadian Donald Hings in 1937, fellow countryman Alfred Gross who patented the technology in 1938 or Motorola (then the Galvin Manufacturing Company) whose SCR300 model was the first to collect the ‘walkie talkie’ moniker.

It’s hard not to argue that Motorola was the most successful at developing the two-way radio technology, driven by military need. The first fully hand-held unit, the iconic AM frequency SCR536, debuted on battlefronts in 1940 and, somewhat confusingly was deemed a “handy talkie”, a phrase Motorola later patented. The company then launched the first portable two-way FM radio, the weighty SCR300, which had to be carried in a backpack and offered a range of between 10 and 20 miles.

Two-way today

Technology has of course moved on and today’s two-way radios are relatively compact, lightweight and offering anything between two and 14 channels, with the greater choice necessary in areas with congested frequencies. Automatic frequency scanning and hands-free applications are other user-friendly innovations whilst design improvements have seen more rugged and even waterproofed models introduced. Their durability and versatility means two-way radios are widely employed every day by:

• Security and facilities management personnel
• Taxi, courier and transport businesses
• Construction managers
• Event organisers
• Teachers marshalling school pupils
• Enthusiasts
• Local authorities
• Commercial, military and personal marine communications