Could someone tell me what is making this signal?

[5Rya]

Hello, I was monitoring my local fire department frequency and noticed this sound that was being transmitted over the frequency. Here is a link to the sound = https://soundcloud.com/user-87865813-726875959/scanner-audio. Thanks

 

[clbsquared]

Sounds like someone is sitting on the mic and keying it up by accident.

 

[nd5y]

It might help if you posted the frequency and location where it was heard.
It sounds like 1200 baud AFSK data like what is used by SCADA, ANI and OTAR.

 

[5Rya]

I'm surprised as its been going on for at least an half hour on and off. I would think the dispatcher would come on and say there is an open mic.

 

[RFI-EMI-GUY]

It is probably SCADA. If this is a fire dispatch channel, it could be Zetron fast FSK polling various fire stations to ensure a link is available for the station alerting. You should hear voice dispatch occasionally. Otherwise it is just SCADA terminals such as used at sewage pump stations .

 

[reconrider8]

the reason the dispatcher doesnt hear it im guessing they have a pl tone or dcs tone set