EPIRB/ELT Beacon Signals

[Net-5]

Here's another question related to marine radio signals. Has anyone here monitored 121.5 or 243MHz analog and picked up any EPIRB or ELT signals? Do they generate an audible tone of some kind while transmitting?

I understand that since February 2009, analog 121.5 and 243MHz has been discontinued as a method of communicating beacon distress signals to SARSATs, and that signals to SARSATs are supposed to be digital in 406MHz now. If somebody happened to have a digital scanner tuned to 406MHz when an emergency beacon signal was transmitted within range, any ideas on what it might sound like? My guess is that it might sound something like the computer generated data bursts for public safety MDT/MDC comms... ?

Any ideas?

 

[gewecke]

I'm not sure if the EPIRB's are d/c'd or not but there's still interesting traffic from time to time on them.
I keep 121.5, 156.8, 243.0, and 406.0mhz. in all the time! What's it gonna hurt,right?
N9ZAS

 

[FLRAILMAN]

EPIRBS,ELTs,Sarsat

Gewecke is right, monitor all of his listed frequencies as only EPIRBS & ELTs are (SLOWLY) transitioning to 406.0 MHz, all of the other frequencies will continue to be used for SAR operations.

FREQUENTLY ASKED QUESTIONS

To hear a recording of an activated ELT, go to:

Freq Of Nature
Click on: Frequencies
Click on: Aviation
Click on: Aviation monitoring
Click on: Aviation monitoring again
Scroll down to Emergency Locator Transmitter (ELT)
Click on: Wave file

 

[Net-5]

Great information! Thank you both.

 

[Hooligan]

The 406MHz EPIRBs just transmit a very brief data burst at preset intervals, however, the 406MHz EPIRBs are also supposed to transmit the analog warbling tones on 121.5MHz -- that's how (in the US) CAP/USCG would RDF the signal once they got the basic SARSAT position data passed to them.

 

[FLRAILMAN]

And with Hooligan including CAP in the natiowide SAR plan you might as well add CAPs primary SAR frequency to the list Geweke gave you. 148.15 MHz.
FLRAILMAN

 

[Net-5]

And with Hooligan including CAP in the natiowide SAR plan you might as well add CAPs primary SAR frequency to the list Geweke gave you. 148.15 MHz.
FLRAILMAN

Sounds like a plan, thank you to all.

And Freq of Nature is a very interesting site! Thanks, FLRAILMAN.

 

[gewecke]

And with Hooligan including CAP in the natiowide SAR plan you might as well add CAPs primary SAR frequency to the list Geweke gave you. 148.15 MHz.
FLRAILMAN

In a recent thread on RR I read that CAP's primary frequency was changed to 148.1250mhz. The secondary is 148.1500mhz. I'm not sure if this is nationwide,or just for certain areas though?
Also do you guys happen to know if 406mhz. is supposed to be am or fm mode?
N9ZAS

 

[FLRAILMAN]

Flip flopping frequencies

Qewecke: I read that post somewhere on RR a couple of weeks ago about a new communications bandplan for CAP, I cant find it though. For years CAPs primary frequency was always 148.15 MHz with 148.125 being the secondary so now I guess they flip flopped them for God knows why, good catch, I hope whoever posted the new bandplan submitted it to the RR database for updating. I Googled a number of EPIRB/ELT websites and different sites claim that the SARSAT frequencies are either 406.0 MHz or 406.025 MHz & the frequency modes are AM or FM & some list not only AM and FM but SSB so if somebody really knows, please enlighten us.
FLRAILMAN

 

[gewecke]

Qewecke: I read that post somewhere on RR a couple of weeks ago about a new communications bandplan for CAP, I cant find it though. For years CAPs primary frequency was always 148.15 MHz with 148.125 being the secondary so now I guess they flip flopped them for God knows why, good catch, I hope whoever posted the new bandplan submitted it to the RR database for updating. Good catch. The 406.0 MHz SARSAT frequency mode is FM.
FLRAILMAN

FL, the thread I saw this in had to with CAP going to APCO 25 if that helps? Lately in this area there's been some activity on 148.1250mhz. also FYI.
N9ZAS

 

[FLRAILMAN]

EPIRB/ELT Info websites

N9ZAS, check the edit on my last post.
FLRAILMAN

 

[eorange]

only EPIRBS & ELTs are (SLOWLY) transitioning to 406.0 MHz...
...To hear a recording of an activated ELT, go to:

I heard that sound once on 243.0 at the Cleveland airshow, when a helicopter took a hard bounce upon landing.

So are you saying that a ELT beacon on 406.0 will sound just like that?

 

[FLRAILMAN]

EPIRBBS,ELTs & SARSAT

the 406mhz epirbs just transmit a very brief data burst at preset intervals, however, the 406mhz epirbs are also supposed to transmit the analog warbling tones on 121.5mhz -- that's how (in the us) cap/uscg would rdf the signal once they got the basic sarsat position data passed to them.

flrailman

 

[Net-5]

FYI on the CAP comms...

I'm a former CAP cadet and senior member. I have been away from the organization for quite a few years now, but I have also kept up on reading articles and information related to CAP comms from Oregon Wing and Pacific Region.

For many years, CAP comms were a collection of personally owned radio equipment of differing capabilities. Eventually, the AF decided to replace the personally owned CAP radios and gear with AF equipment, thus making the system uniform and relieving individual CAP members of the expenses involved. And presumably, the AF equipment would be better and provide expanded comm abilities. Hopefully, CAP won't get stuck with a bunch of old castoffs that the AF no longer wants, as I had seen that happen before with other supplies...

I decided to mention this because I'm finding that some folks on RR seem to think that CAP members still provide all their own comm gear and always will. And unless things have changed back to the old way of doing things, this is not the case anymore.

 

[gewecke]

That's interesting since almost all of the newer generation gear out there still has provisions for CAP mods so members can do it themselves.
N9ZAS

 

[Net-5]

That's interesting since almost all of the newer generation gear out there still has provisions for CAP mods so members can do it themselves.
N9ZAS

Good point. I'll do some more research and see what I can find.

 

[ecps92]

Actually CAP has transitioned to Narrowband and 148.1250 seems to be the NEW Primary Rptr Pair, with 148.1500 being the Alternate.

More info is in the CAP WIKI

And with Hooligan including CAP in the natiowide SAR plan you might as well add CAPs primary SAR frequency to the list Geweke gave you. 148.15 MHz.
FLRAILMAN

 

[ecps92]

Not to hijack the thread, but join us in the Federal Forum and post the CAP tones you find.

PS, they will be Analog with the Capability of using P25 [Dual Mode]

FL, the thread I saw this in had to with CAP going to APCO 25 if that helps? Lately in this area there's been some activity on 148.1250mhz. also FYI.
N9ZAS

 

[ecps92]

Wings are issued from HQ based on numbers [Personnel, Activity etc] however, Members can [must ask permission and have the radio from an approved list] and still do, purchase their own radios. All depends on how much they want to spend. Analog or Dual Mode.

Not all of the Assets appear to have been distributed, which might bring reason to the quiet Net Nights

Sorry for the Hijack, anyone wanting to continue the topic, join the Federal Forums [search for Civil Air Patrol] we now return to our Maritime Monitoring.

FYI on the CAP comms...

I'm a former CAP cadet and senior member. I have been away from the organization for quite a few years now, but I have also kept up on reading articles and information related to CAP comms from Oregon Wing and Pacific Region.

For many years, CAP comms were a collection of personally owned radio equipment of differing capabilities. Eventually, the AF decided to replace the personally owned CAP radios and gear with AF equipment, thus making the system uniform and relieving individual CAP members of the expenses involved. And presumably, the AF equipment would be better and provide expanded comm abilities. Hopefully, CAP won't get stuck with a bunch of old castoffs that the AF no longer wants, as I had seen that happen before with other supplies...

I decided to mention this because I'm finding that some folks on RR seem to think that CAP members still provide all their own comm gear and always will. And unless things have changed back to the old way of doing things, this is not the case anymore.

 

[ecps92]

Newer Generation Amateur gear

Commercial has always been approved [Wideband] for CAP/MARS
Now they must be Narrowband and the list of approved radios is limited

That's interesting since almost all of the newer generation gear out there still has provisions for CAP mods so members can do it themselves.
N9ZAS