Morris County Fire/EMS Dispatch DTMF Tones

[gmarconi]

Anyone know the purpose of the DTMF tones that sometimes precede pages on 476.2875?

I've heard them before dispatches for Chatham and Washington Twp and the county wide nightly pager test.

 

[jjcsx]

I am not familiar with the specific county you have listed in your question, but generally speaking the DTMF tones are used to activate in-station and portable pagers that units use to be alerted to a new call. If they also use the long 2-tone QCII tones, the DTMF tones may only be used for a few specific pagers in use by that department, i.e most of their pagers use QCII, but they may have a few different units in use that use the DTMF instead. This would be the case if the DTMF tones are fairly rare compared to any other type of paging signal in use on their frequency. Hope this helps!

 

[Tech792]

Most likely to activate outside station sirens/horns

 

[W2SJW]

Most likely to activate outside station sirens/horns

Good point. If you hear a DTMF string on dispatch all by itself, those are usually to unlock a radio Knox-Box on a specific fire apparatus.

 

[KDD904]

Actually in this particular case, the DTMF tones are used to activate local receivers which pass the paging tones to local VHF transmitters. This is a "temporary" setup until such time as all the first responders have UHF pagers.