2-Way radios have come along way. Most of us were not even born when radio
communications as we know it got started. 2-Way radio communication dates back to World
War I when the introduction of vacuum tube equipment arrived. (During World War I it was
illegal for private U.S. citizens to possess an operational radio transmitter) Shortly
after World War I with the need to communicate realized, advances were made in vacuum tube
technology resulting in Trans Atlantic broadcasting.
Closer to home, in 1928 the Detroit Police Department utilized wireless communications
by operating a one-way radio system.
In 1933 New Jersey Police were the first to use the airways for 2-way communications,
with a Base to Mobile operation.
Shortly into the 1940’s crystal controlled portable radios were developed.
Although these portable units weighed about 5 pounds and only had a range of about 1 mile,
the Connecticut State police began operating what is in today’s standard the first FM
2-way radio system.
With the 1960’s solid-state circuitry started to replace vacuum tubes and the
2-way industry achieved a new era. Radios started to become less cumbersome and more
economical. With this new circuitry development also came the ability of enabling the same
frequency to be shared by more than one entity. This is known as tone coded squelch
(CTCSS).
The first commercial microprocessor was introduced in 1971 that permitted various
circuits to be incorporated in a very small configuration. It also allows for multiple
simultaneous procedures to be performed.
Over the years we have seen both government agencies and private companies migrate from
low band to high band VHF frequencies. UHF frequencies, and 800 and 900mhz Frequencies. We
have also advanced from vacuum tube to crystal to synthesized radios. We have seen the
size of portable radios shrink from the size of a cracker box to the size of a pack of
cigarettes. Battery technology is keeping up with the smaller radios too. We started out
with a lead acid battery advanced to a smaller higher capacity nickel cadmium battery to
the nickel metal hydride to the lithium ion. We have seen radios go from a simple 1 or 2
channel unit with a selector knob to radios than can store 500 frequencies and that have
alpha-numeric read outs.
In the early days the FM, modulated radios operated from radio to radio using only one
frequency (Simplex), which had a very limited range. As urban development grew it was
necessary to increase coverage area and penetration. Radio systems began to incorporate
the use of repeaters, which would pick up the signal and rebroadcast (repeat) it at a
higher power level. As we continue to grow so do the enhancements to radio systems. We
have seen the combining of multiple repeaters with computer logic controllers to
efficiently use spectrum known as trunking systems. These days with radios being more
widely used and spectrum being harder to come by, it is necessary to make even more
improvements. With the use of digital technology we can now send multiple transmissions in
the time it would take you to say "Good Morning".
Where will it end? ………. Stick around, we’ll keep you informed!
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