7.790 USB-Interesting Activity.

[hfdxer]

This is the frequency for the "Angeles Verdes"- green Angeles. They are the AAA of Mexico. In Los Angeles I'm able to hear many mobile and base units. On the same frequency I hear a "chirp" sound. Anybody have any idea what the "chirping sound" is. Sometimes the chirping sound is long, followed by a short sound. Sounds like some kind of propagation marker or something. Today as I was monitoring the activity I also heard a male signing.

 

[ridgescan]

Probably what they call OTHR (over the horizon radar) causing that sound that's a neat catch you got.

 

[ka3jjz]

Per the UDXF, ALE has also been noted on this freq. The Green Angels are a definite player on this freq, but also some other unid digital stuff, perhaps Russian Intel. Even some thinking some users of Contestia or Olivia (yes, the ham digital modes) here.

73 Mike

 

[SCPD]

This is the frequency for the "Angeles Verdes"- green Angeles. They are the AAA of Mexico. In Los Angeles I'm able to hear many mobile and base units. On the same frequency I hear a "chirp" sound. Anybody have any idea what the "chirping sound" is. Sometimes the chirping sound is long, followed by a short sound. Sounds like some kind of propagation marker or something. Today as I was monitoring the activity I also heard a male signing.

Im getting the beep with a short data like burst at the end of each beep followed by a series of long chirps like a telephone ringing. Sounds like a propagation beacon.Very week signal here on the east coast.

 

[ka3jjz]

Take a look at the websites mentioned in this thread - by comparing the sounds and trace of the digital squawking you should be able to determine the mode being used.

http://forums.radioreference.com/digital-signals-decoding/196111-multipsk-users-identify-modes.html

73 Mike

 

[Hooligan]

Do you know what an Ionosounder sounds like? Maybe someone's running some old Chirpcomm gear on that & other freqs.

 

[ka3jjz]

The only way this mode issue is really going to be cleared up is for someone to record and post it. That way folks can use software (like SR5) to obtain a trace and use the websites listed to see what it is, or perhaps recognize it by ear. ALE (or as MultiPSK lists it, MIl-188-141A) has a very distinctive sound which is easy to recognize. It wouldn't surprise me in the least if at least some of the Green Angels are using mobile HF equipment using MultiPSK on a laptop...73 Mike

 

[Token]

This is the frequency for the "Angeles Verdes"- green Angeles. They are the AAA of Mexico. In Los Angeles I'm able to hear many mobile and base units. On the same frequency I hear a "chirp" sound. Anybody have any idea what the "chirping sound" is. Sometimes the chirping sound is long, followed by a short sound. Sounds like some kind of propagation marker or something. Today as I was monitoring the activity I also heard a male signing.

The Green Angeles do indeed use ALE on this freq as others have pointed out. However, I do not think that is what you are describing as the chirping sound. Or possibly you are describing it as well as something else.

Slightly higher in freq, 7793.3 kHz center freq, you will find WNU Globe Wireless. It makes a "chirp, chirp, chirp" sound and occasionally throws out a couple of long "chiiiiirrrrpsss" As soon as I tuned to 7790 kHz in USB with a wide filter, say 3 kHz or wider, I heard this and felt pretty sure it was what you were describing.

Now, the other sound, like what you are describing as a propagation marker. That is quite likely the ALE burst that is on 7790 itself. Or, it might actually be a sounder hitting the freq occasionally, although I have not heard one hit on the freq in the last 30 minutes of listening. All I have heard is the ALE and the Globe Wireless.

But, as someone else has pointed out, no one is going to know for sure until you record what you are hearing and post a link. I can ID what I am hearing, but that might not be the same signals you are hearing at your location.

T!
Mohave Desert, California, USA

 

[ka3jjz]

What Token is describing sounds like a PACTOR signal. I've heard what he describes many times with a bunch of short chips then a long one - although it's a first for me to think that WNU is using it (A SITOR idle marker is usually comprised of a CW ID followed by several long bursts). Anyone check their website or hear a CW ID? 73 Mike

[edit] Confirmed, per UDXF loggings - WNU uses GW Pactor or GW Dataplex on this frequency.

 

[poltergeisty]

This is the frequency for the "Angeles Verdes"- green Angeles. They are the AAA of Mexico. In Los Angeles I'm able to hear many mobile and base units. On the same frequency I hear a "chirp" sound. Anybody have any idea what the "chirping sound" is. Sometimes the chirping sound is long, followed by a short sound. Sounds like some kind of propagation marker or something. Today as I was monitoring the activity I also heard a male signing.

Muhahahah, those are secret Homeland Security trackers, my friend. :lol:

 

[hfdxer]

Green Angeles-equipment and logistics

thanks for all of the info everyone is providing. I have been listening for a while to this frequency and this is what I have concluded so far
the mobile units all identify with the letter R followed by a number: For example I have heard R-30, R12, etc. The base units have the M letter identifier. Ensenada base is M-12, Hermosillo is M-15, Mexico City interestingly does not identify with an M the mobile units refere to it as "Radio Mexico" When the base is calling the mobile units the call themselves "patrullas" for patrols.
From my travelings downs south I have seen these Ford F-150 especially equipped vehicles. They use the Hustler resonator mobile whips with an extreme tilt angle (NVIS propagation). In crossing the california border with Mexicali you can spot the dipole up at about 50 feet in one of there base stations near the border checkpoint. My goal is to find out what kind of mobile radios they are using. I know that the antennas are Huslter 40 meter resonator- most likely with an antenna tuner of some kind. I'll get back when I find some more info.
From my qth in Los Angeles I can receive traffic from as far as Mexico City base. The mobile units are mostly from the northern part of Mexico. This frequency gets extremely busy during the vacation period as many traveler head down south.