kg9qm said:
So I don't miss my one shot at it, does NOAA broadcast the SAME code for Marion County when the sirens go off at 11AM, or just the 1050 Hz tone?
As Tim explained, it's two different warning systems.
NOAA's All-Hazards Radio system tests their warning activation every
Wednesday morning unless severe weather threatens. Each of the transmitters controlled by the Indianapolis NWS office gets an activation code from the office which causes the transmitter to send out the 1050Hz alert tone and the appropriate SAME codes.
For additional information, you can see a map of Indiana with the transmitter locations and coverage areas at
http://www.crh.noaa.gov/ind/?n=nwrimage. The map is a little confusing because it's trying to show multiple levels of information, so it may take some careful studying to understand. Note that some counties are covered by more than one transmitter. NWS has another chart at
http://www.weather.gov/nwr/CntyCov/nwrIN.htm that shows counties, SAME codes, transmitter frequencies, and also transmitter output power.
Marion County Emergency Management activates the warning sirens in Marion County based on their internal protocols. To the best of my knowledge, there is no direct (i.e. non-human) interface between the NOAA All-Hazards Radio alerts and the warning sirens. As most of us in the county know, the Marion County sirens are tested on
Friday morning at 11am.
The Marion County sirens used to be triggered by a series of DTMF tones on a particular VHF frequency. That system may have been completely decomissioned in favor of some other radio data system. I know the sirens in Hendricks County are moving to a MOSCAD (Motorola siren activation system) system that is transmitted on a SAFE-T talkgroup.