Hobbies And Interests
VHF Phrases
Very high frequency or VHF radio is a range of frequencies (30 to 300 MHz) used for short-distance communications. Sometimes, you can use a scanner radio to receive these signals and listen to ongoing conversations. For decades, radio communicators looked for ways to make transmissions efficient. To cut down on transmit time, many radio operators use shorthand words when talking on the radio. This shorthand includes information intended to be communicated quickly. Phrases are not only used by emergency communications personnel, they are also used by ham radio operators.
"Simplex," for example, means one-to-one radio communication. "Hold the air" is another common term which means an emergency is in progress and to keep the radio frequency clear until the emergency is over. When a signal is very clear and strong, it̵7;s said to be "full quieting." "Duplex" means a system where people can talk and listen at the same time. A "patch" can also be used to link more than one frequency to another.
Phonetics
Since emergency personnel use radio communications, they had to also find ways to ensure their message was clearly understood. When a radio signal is weak, it̵7;s often difficult to pick out the words. To address this problem, dispatchers started using phonetic alphabets.
For example, if a dispatcher had to broadcast a message that noted a license plate such as DFD 9X9, it would be said as Delta Frank Delta 9 X-ray 9. Saying it in such a way that spells each letter out makes it easier to hear especially when the signal has noise or is weak. The phonetic alphabet is part of a standard International Telecommunication Union phonetic alphabet.
10-Codes & Signals
A system of numbered codes was developed in the 1930̵7;s, and later expanded in 1974 by Association of Public-Safety Communications Officials-International. These codes are referred to as 10-codes. This type of radio communication talk is so varied that in 2006 the U.S. government recommended standardization or discontinued use by dispatchers. Today, 10-codes are still used primarily by police, fire and emergency medical professionals who provide critical communications for their city or county service areas. For example, ten-eight means in service while ten-seven means out of service. In addition to ten-codes, certain numbered "signals" are often attached to radio communications.
Signals are an additional way of further explaining the nature of a call or situation. These signals vary by city and department. For example, in Volusia County, Florida, ̶0;Signal 0̶1; means caution because of a possibly armed person. Signals are also used by police so civilians don̵7;t hear the actual meaning of the message as a matter of officer safety.
Frequency Allocation
Many large city police, fire and emergency medical service groups have left VHF radio because of overcrowding on those frequences. However, the VHF radio spectrum still has several users which are split throughout the frequency range. The National Telecommunications and Information Administration allocates frequencies.
Warnings
Using a scanner radio while mobile may be illegal in some cities and states. Exceptions exist for licensed ham radio operators and emergency officials including EMTs, off-duty police and similar professionals. Minnesota, for example, has made it illegal for unauthorized scanner radio use. Consult your state or local regulations website for specific legal details.