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Some Amateur Radio equipment has to capability of sending distress messages in the form of an EMERGENCY! beacon. These messages are serious and should be handled appropriately, as they are similar to a PAN or SOS voice call.

What do I do if I recieve an EMERGENCY! beacon ?

1. Attempt to contact the station sending distress messages to confirm the situation.

  • Send a message via APRS
  • Attempt to call the staion on voice, using VoiceAlert, 146.500, 439.000 or local repeater
  • Attempt to make contact with the station via Telephone (if thier number is known)

2. Send a beacon notifiying that you are working on this event.

3. If unable to contact in person:

  • Check contact details listed in the ACMA database
  • Contact the authorities
  • Go in person if it's close and the nature of the distress is known to be safe for the visiting operator.
    (If you don't know what's happening, never visit the site -- leave it to the authorities.)

General Comments

If you don't think a distress signal is for real, there are other things that can be done short of asking the local authorities to make a rescue run. The phone book is a good start. Cross reference the call sign to the address with QRZ or the ACMA database, check name and address against the phone book and see if you can call direct.

If that does not work, try your local police non emergency phone number. Explain you are seeing an emergency signal and how, then give them the address and name of the ham, asking them to check the welfare of the person.

See if you can network with another ham in the area of the emergency transmission and ask if they'll stop by and check on the person.

If the only address available in the ACMA database is a PO Box number, you may be stuck calling the authorities and asking them to do the check by sending a car to the area where the APRS transmission is coming from. Be sure and tell them how you know of the possible problem and that they be looking for the person in a vehicle or in a building. The only clue of exactly where the person is might be a radio antenna.

Also consider the nature of the APRS unit transmitting. Sending a message over APRS to a straight tracker like the TinyTrak will do no good at all. The tracker won't receive messages, the owner will not see it and so may continue sending the emergency signal.

We all need to assume the signal is real and act accordingly.


It's essential that any emergency system like this be tested.

It's suggested that individuals wanting to conduct their own function test do so OFF of the national APRS frequency of 145.175Mhz. Full station function testing can be accomplished without risking a 'false alert' on the national system.

Any Emergency Beacon that is on 145.175 must be dealt with as 'the real deal' until proven otherwise, either by some indicator in the beacon itself or contact with the originating station.

Sending of EMERGENCY! beacons

APRS Emergency beacons are only properly supported in the Mic-E (compressed) beacon format. The APRS protocol specification has no reference for an Emergency beacon format for non-compressed messages. As a result, most software will only respond to an EMERGENCY! beacon sent in Mic-E format.

There is an EMERGENCY! symbol that can be used in a non-compressed beacon, however there is no guarantee that client software will activate alarms if this symbol is present.



How APRS clients handle Emergency beacons


Although not widly used, aprsDOS has a feature that responds to emergency signals, requiring user intervention to silence the alarm.

Kenwood TH-D7

Unfortunatley the TH-D7 did not respond in the way we would have hoped when it recieved an EMERGENCY! beacon. Instead of alerting us to the message, it simply displayed a beacon posit in the same way as a standard posit. It does however SEND a correctly formatted EMERGENCY! beacon.

Kenwood TM-D700

The D700 responds by a series of beeps, and displaying "EMERGENCY", the call, distance and direction on the display. This display remains locked displaying this information until it is manually acknowledged.




UI-View itself has no support of EMERGENCY! beacons, however the APRS Emergency add-on project by Giuseppe IW2JZQ adds functionality to handle them. (Initial Installation is in Italian, but program does have English). To install this addon, first install version 1.11, then upgrade to the latest EXE file. Note that versions below 1.21 will only work if AGWPE is used to connect the TNC to UIView

When an EMERGENCY! beacon is recieved, the program sounds an alarm and pops up a window with the details. It also draws a circle around the station sending the beacon on the UI-View map display.


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