What's up? Intrigue on US Air Force Emergency Action Message frequency 15016 kHz USB

[@StratmanII]

I don't think I have ever come across EAM signals on this very frequency, but all the same I'm for happy for my friend Andre who managed to record this and share this interesting catch on his channel! ☺️📻👍🏼🌍 The moody, low light conditions and the camera angle of this video clip also enhances my experience watching this episode. I must say your filming skills have also gone a long way since I first watched your earliest YT shorts with your trusty PL-368! 😀 Sometimes I wonder if the USAF transmits this as part of their transmission test, to verify that this signal can still be picked up from various locations in the world. They can also broadcast on shortwave using coded CW, RTTY or FT-8 signals instead of using NATO phonetics. FT-8 is also used by some ham radio operators when ionospheric conditions are at their worst, when voice transmissions are nearly impossible to comprehend.

[@swlistening]

Thanks for your kind words, I appreciate the compliment on the camera angle! I'm always trying to improve 😄 About the EAMs being transmitted as test signals, I think that is probably the case. I think some of the EAMs probably do contain actual action messages, but I think sometimes they are just tests to make sure that they are received well.

[@StratmanII]

@@swlistening Well, we both can agree that natural light and shooting that nice Kenwood R1000 obliquely makes the radio appear three dimensional, rather than the perpendicular camera angle that most newbies resort to. Thanks for not using head-on illumination as that results in glare and the radio appearing "flat" on my screen! 😀 A military power like the U.S. with its far advanced technology will not use shortwave as its primary means of EAM communications, but it also doesn't mean that it will forego a tried and tested medium like good old shortwave, which it has had many decades of experience with - long before satellite comms and Internet became the mainstream. 🛰📡🌎

[@fernandoscrenci4874]

@@StratmanII , The PL- 368 has amazing find wave on signaling receive paths!!!

[@SSJIndy]

Used to hear on 6660 messages like 'Andrews, Andrews, this is looking glass' and various additional info. Sometimes just asking for a weather report, sometimes coded messages. This was 20 years ago

[@swlistening]

Hi Don, thanks for commenting. This sounds very interesting, it seems to me as if everything is coded these days. I never hear anything I can understand in these messages from AFB.

[@neetintel]

I've dedicated a lot of the last 3 years to monitoring the HFGCS. Many of these longer messages are actually routine, scheduled messages. 15016 kHz is a typical frequency used for many years now, so it isn't surprising to hear messages on that frequency at all.

[@swlistening]

Thanks for your comment and the information! Just to clarify, I wasn't saying that the frequency is unusual, I know this is one of the regular EAM frequencies. I found the increased number of messages somewhat unusual, in my monitoring I usually don't hear so many messages in one evening.

[@neetintel]

@@swlistening Oh yes! The date you were listening was a higher period of traffic. I believe it probably had to do with Global Thunder 25. Not all of the dates can be anticipated in advance, but there are a few dates during the year where what I refer to as 'SKYMASTER events' correlate to much higher periods of traffic. As opposed to just advertising my own social media, I also have done some posts on the HFUnderground SWL forum, and there is a thread called "US STRATCOM SKYMASTER Traffic Log". It eventually became obvious to me that a lot of the dates appeared to be routine - for example, a Wednesday in January 2023 and a Wednesday in January 2024 both had SKYMASTER events, so I expect a Wednesday in January 2025 to also be another great day to listen for much more traffic than usual.

[@raymondmartin6737]

I once hearrd a voice message on Shortwave that ended with mentioning Andrews AF Base.😊

[@swlistening]

Hi Raymond, that's quite interesting that they mentioned the base name!

[@rtcurtis5858]

Very interesting, Andre. Sounds like some long delay echo in that transmission. There is a retired Navy Sub Sonar man, Aaron, who has a YT channel, Sub Brief. His most recent video talks about the networked communications used between US Navy activities. Maybe of interest? Randy-Illinois

[@swlistening]

Thanks Randy. Maybe the echo is due to the fact that the signal is being transmitted by several stations, but not all the signals reach me at exactly the same time. Thanks for the suggestion about Sub Brief, I found it and subscribed, looks fascinating!

[@stargazer7644]

@@swlistening That's exactly it. These are transmitted simultaneously from multiple stations all over the planet to guarantee global coverage. This results in echo as the signals take slightly different amounts of time to reach you.

[@timbermicka]

Maybe it's related to NATO's ongoing "Steadfast Noon" nuclear deterrence exercise?

[@swlistening]

I'm sure it must be related to some current events.

[@sentul5558]

@@timbermicka This could be. It was quiet yesterday, normal type messages. Today very busy with more separate messsage but nothing happening really other than the exercises.We will see when the exercises end.

[@nohandle62]

Heard a similar message, same frequency, in a woman's voice on another YT channel. She said, "Bar Candy" several times, then "Help".

[@swlistening]

That's quite interesting, do you remember the name of the channel, I would like to watch this video!

[@nohandle62]

@@swlistening kzbin.info/www/bejne/gajVYYuQp7lgiposi=jCg_22TmFdpUO8Au

[@nohandle62]

@@swlistening I listened again. They may have said "out". Sorry about that. I think I need to get my hearing checked.

[@swlistening]

@@nohandle62 That's OK, sometimes these signals are not very clear anyway 🙂

[@nohandle62]

I posted the link, but that disappeared. The channel is Steve St Denis.

[@jameyevans29]

Nice radio

[@swlistening]

Thanks Jamey! It is a nice radio indeed, I got this one second-hand in really great shape, everything works.

[@sunsoundz]

The "standing by for traffic" is quite common on all EAM frequencies, especially on 11175 khz..

[@sentul5558]

@@sunsoundz Yes agreed ... would you like to explain what if means please?

[@sunsoundz]

@@sentul5558 As the EAM frequencies are a network for planes, ships ect. , stations are logged on this network and they log on and off. "stand by for traffic" means that the calling station is standby for any incoming call or message from the stations in the network. Then after a while comes "station name OUT" .. means the station with the " station name" closes transmission and will not listen anymore.

[@sentul5558]

@@sunsoundz thank you🙂

[@swlistening]

@sunsoundz Thanks for this Andy! I actually did not know that the "standing by for traffic" was so common. But I don't hear these EAM transmissions very often, it is only during this past week that I heard them very often and very clearly, that was the first time when I heard this.

[@sunsoundz]

There are the following frequencies for EAM messages: 4724, 8892, 11175 and 15016 MHz, all USB. Mostly the transmissions are parallel on all these frequencies.

[@jameyevans29]

I hear this on 11.175 usb on the time. Mainsail mainsail they say. Google has some info on this if you type in this frequency

[@jameyevans29]

*All

[@sentul5558]

Not the same ... sorry.

[@jameyevans29]

I know it’s not Mainsail but it is a EAM

[@swlistening]

Thanks Jamey. From what I have read there are some different types of messages and different call signs, with different purposes. It is all quite fascinating. There are also "skyking" messages. The "mainsail" call sign seems to be the collective call sign for all ground stations. This is quite an interesting thread with many logs, it also has the "bar candy" one like in my video: www.hfunderground.com/board/index.php?PHPSESSID=5pofo5buoab5osrqlut1bndpn1&action=search2

[@jameyevans29]

@@swlistening Thanks for the link!

[@fernandoscrenci4874]

Code actions!!!!

[@Hiram8866]

I've been fascinated by these for years now. I think I know their purpose, but not the contents. I think EAMs are sent to nuclear missiles sites, mostly as a check in, but they could be used as a launch.

[@ocsrc]

The EAM frequency used for the nuclear silos is a dedicated frequency and they do transmit test messages but not often. They have a 2 letter beginning that is the biscuit code The message is made up of the biscuit code, the selection of the primary or secondary target, the time to launch, the butterfly code, the authenticator code of letters, and I think it has a 2 letter checksum code It is a very tight group of letters and numbers and there would be 4 numbers for the time to launch or immediately and the 8 digit butterfly code The butterfly code is only known to the top of the Command structure. It is the way they prevent an unauthorized launched. Back when it was all zeros, it was known to the missiler's But now, it is not. It would be transmitted if there was a real war So they look at the message and say the first 2 letters were BC, they would open the safe and look for the biscuit envelope that says BC They would each look at the authenticator code and compare it to the code received. They would verify they match, and then enter the code into the computer and the time of the launch and set the butterfly code If you listen to that frequency and hear a transmission and they have the 8 numbers I would be worried. I don't think they transmit the numbers in test messages, just letters. And if I had to guess, the ARQ II means this: ARQ II or ARQ2 This is the 240 bd 8 tone burst ARQ mode used in the Rohde & Schwarz MERLIN modem. When the system is found in the 7 tone mode it is in ISS mode, the IRS mode uses an 8 tone signal. Both will be measured as 240 bd (720 bits/sec) with tones shifted by 240Hz. Character set can be ITA2 or ASCII with 8 bit ASCII being the most common. Turkish, German and Italian Diplo stations are the most commonly found users. The Italian Diplo stations seem to favor the 5 bit (ITA2) mode. Turkish Diplo stations have been found using the 8 bit mode for all traffic. Monitoring tip: Its been discovered that all 8 tone channels have ALIS (228.7bd) 2kHz below. So if you hear an ALIS procedure in progress on a frequency it's worth waiting to see if 8 tone traffic appears 2kHz higher soon after. And Ukraine is also listed on other sites as using the diplo stations So, this looks like it has to do with the Ukraine

[@Hiram8866]

@@ocsrc Thanks for the info.

[@swlistening]

Hi Glen, I am equally fascinated by these. Really interesting signals to monitor. I tend to agree with you, I think these messages are mostly check-in messages, but the code can change at any time to actually signify a command to launch an attack. Kind of scary, but very intriguing.

[@swlistening]

@ocsrc Thank you so much for your detailed explanation!

[@sentul5558]

Don't know what they are or mean in real terms and I doubt if USAF would broadcast anything that you and I could make any sense of. USAF have been very active recently as you will be aware. Yemen and the houtis being visited by B-2 bombers dropping some of their latest hardware. USAF are also involved in the defence of Israel from missile attacks and USAF bases could come under attack. Israel is about to launch an attack on Iran ... Standing by for tracffic could refer to both scenarios.

[@swlistening]

Indeed, this would be heavily coded, so there is no way for us to know what is being said. It is true though that there is a lot of US Air Force action these days, maybe these messages are somehow related to actions in the Middle East as you say.

[@frankfoduw-ci8rr]

73

[@swlistening]

Hi Frank! I still plan to talk about your next shortwave contest in my next podcast 😊 How did the previous contest go, did you get many entries? I planned to enter, I kept a log, but I missed the deadline. Next time!

[@sentul5558]

Listened to 15016 around 2330 UTC on two online sdr radios and it is being jammed ... ???

[@swlistening]

That's quite interesting. I did not hear any jamming on my side though.

[@sentul5558]

@@swlistening funny yes. I can't get it here so I went on line. So I went to twente, there was s very loud beating sound. So I tried tbe Canaries, same there.

[@sentul5558]

@@swlistening that noise is still there on twente sdr. Don't know what it is. It covers a bandwith more than 20 kHz from 15001 to 15025.

[@swlistening]

@@sentul5558 Very interesting. I do not hear it at all here in South Africa, checked for it just now. But I hear it on the Twente SDR also, like a ticking noise. Very strange.

[@swlistening]

@@sentul5558 I also heard this beating or ticking sound tonight. Unusual.

[@gorankoilic6571]

I do not understand what they say.

[@swlistening]

We can hear the NATO alphabet, but it's coded, so not really possible to understand the actual message...