FDNY Radio System Question

[york899]

Radio Discipline and Professionalism.

The Radio Out Dispatcher controls the Borough Frequency with commitment and demeanor. Communicating with the highest priority incident commander in the borough at a time, announcing alarms, directing or redirecting units, giving instructions, giving designations, giving messages or receiving reports when necessary.  With the use of the Mixer on/off feature, the frequency will remain silent and accidental transmissions, stuck button/open carrier or unauthorized transmissions will not be broadcast unless the dispatchers wishes to turn the mixer on.
This way with less radio traffic and non-sense broadcast the units in the field will be more attentive to the transmissions of runs or reports. This is one of the reasons why the mixer is left off. With the feature they can also prevent the units from talking to each other via the borough frequency or broadcasting confidential information.

The mixer is turned on after the initial calling by a unit (as per policy). The dispatcher will acknowledge the unit and simultaneously turn on the mixer allowing the unit's message to be rebroadcast. The mixer will remain on until the dispatcher signs off with his/her name and number. The only other exceptions would be by request of an incident commander, at the discretion of the dispatcher if the message/information is sensitive or confidential, and when there is the accidental or unauthorized transmissions.

 

[Firebuff66]

Its not a repeater system at all. Has all the parts of a repeater , looks like a repeater to you and I. However the brains behind it are not a repeater controller. Anyone that has ever worked a dispatch center can think of it like a console patch between the Rx and TX radios

It is a 'full duplex' system and it is configured without an automatic repeater so that both sides can talk and listen to each other at the same.  This allows the possibility of either side passing important information even when the other is talking.  We accept and use this concept daily with telephones.  You can't interrupt a long winded talker on a repeater because they won't hear you, but you can do it on a phone.

Just to be clear for people its not a true Full Duplex system as a phone would be, The dispatcher can talk out and listen at the same time because the field units talk in on a different frequency then the dispatcher talks out on, But the field units can only do 1 or the other. Motorola XTL5000/XTS5000 or the amazing XTS3500 they still have (sarcasm) radios are not capable of full duplex operation unless its used with a DVRS. The mixer is just a repeater, but instead of turning the repeater on and off they have it set up to key or un key, so when they turn the "Mixer" on they are just putting the repeater into constant transmit instead of letting it key up and down on its own. Same as turning the repeat function on and off but they turn it on and stayed keyed and then turn it off. No one can deny they have great radio etiquette on the main channels.