What are Fdny Dispatch Tones and how do they work?
Fdny Dispatch Tones are the sounds that are used by the Fire Department of New York (FDNY) to alert firefighters of an emergency call. They are also known as pager tones, house tones, or special signals. Fdny Dispatch Tones are composed of two frequencies that are transmitted simultaneously for a specific duration. The combination of frequencies and duration determines the type and location of the emergency.
Fdny Dispatch Tones are part of a full duplex system with voted receivers and a mixer. This means that the received audio from the mobiles and portables is injected into the audio transmitted by the base station when the mixer is turned on. This allows the firefighters to hear both the tones and the voice dispatch at the same time. The FDNY dispatch frequencies are not repeaters in the traditional sense, as they do not retransmit the received signal[^2^].
Fdny Dispatch Tones are based on a system developed by PURVIS Systems Inc., a company that specializes in fire station alerting systems. The PURVIS system uses a digital encoder to generate the tones and a decoder to identify them. The encoder and decoder can be programmed to produce and recognize different tones for different fire companies, battalions, divisions, boroughs, and special units[^3^].
Fdny Dispatch Tones are not only used for alerting firefighters, but also for communicating information such as status updates, requests for additional resources, or emergency signals. For example, a mayday signal is transmitted by pressing a button on the radio that sends out a tone of 800 Hz for 1 second, followed by 970 Hz for 3 seconds. This tone is repeated until the firefighter is rescued or cancels the signal[^3^].
Fdny Dispatch Tones are an essential part of the FDNY's operations, as they provide a fast and reliable way of notifying firefighters of an emergency and conveying important information. Fdny Dispatch Tones can also be downloaded as ringtones for personal use by fans of the FDNY or fire service enthusiasts[^1^].
Fdny Dispatch Tones have a long history that dates back to the origins of the FDNY. The FDNY was established in 1865 as a paid professional fire department, replacing the volunteer fire companies that had served New York City since the colonial period[^2^]. The FDNY inherited the fire alarm telegraph system that was installed in 1852 by the New York Fire Department, a municipal agency that supervised the volunteer fire companies. The fire alarm telegraph system used electric signals to transmit the location of a fire from street boxes to fire stations. Each fire station had a gong that sounded a unique code corresponding to the box number. The firefighters then consulted a map to find the location of the fire[^3^].
The fire alarm telegraph system was gradually replaced by radio communication in the 20th century. The FDNY began using radio dispatching in 1928, using a single frequency for all five boroughs. The radio dispatching system was improved over the years, adding more frequencies, channels, and equipment. In 1977, the FDNY adopted the PURVIS System for generating and decoding Fdny Dispatch Tones. The PURVIS System allowed for more flexibility and customization of the tones, as well as faster and clearer transmission[^3^].
Fdny Dispatch Tones are still used today by the FDNY, along with other forms of communication such as voice messages, text messages, and mobile data terminals. Fdny Dispatch Tones are an important part of the FDNY's culture and tradition, as they reflect the history and evolution of the fire service in New York City. Fdny Dispatch Tones are also a source of pride and recognition for the firefighters who respond to them every day[^1^]. 061ffe29dd