GMRS/FRS Channel 7 Interference

[afchev]

Can someone monitor GMRS Channel 7 (462.7125 MHz) and tell me what you hear? I usually scan GMRS when I am out and about around town, and for several days now I can hear what sounds like some sort of data packet transfer or something similar (for lack of better terminology.) Just curious as to what it might be. Can be heard all around the city. When I get a second I plan on hooking up my RTL-SDR to see what frequently its actually on as I suspect its close enough to 462.7125 MHz to be causing some bleed over.

 

[afchev]

And I mean within Las Vegas as I've just realized this is a statewide forum.

 

[DeoVindice]

Does it sound like any of the clips on this page?

Digital Mobile Radio (DMR) - Signal Identification Wiki

Digital Mobile Radio (DMR) is an open digital mobile radio standard defined by ETSI and used in commercial products around the world. Mostly used by private network and local police, can be encrypted. Used in MOTOTRBO products.

www.sigidwiki.com

 

[afchev]

Does it sound like any of the clips on this page?

Digital Mobile Radio (DMR) - Signal Identification Wiki

Digital Mobile Radio (DMR) is an open digital mobile radio standard defined by ETSI and used in commercial products around the world. Mostly used by private network and local police, can be encrypted. Used in MOTOTRBO products.

www.sigidwiki.com

Nothing on that page sounds similar. The best way I can describe it is like ACARS or APRS just a different tone.

 

[afchev]

Best I could do at the moment is a phone recording.

 

[nd5y]

Best I could do at the moment is a phone recording.

It's 2400 baud AFSK data. Probably SCADA or telemetry that isn't legal on FRS or GMRS. The good thing is if it transmits that often all the time it will be easy to track down.

 

[afchev]

It's 2400 baud AFSK data. Probably SCADA or telemetry that isn't legal on FRS or GMRS. The good thing is if it transmits that often all the time it will be easy to track down.

Very interesting thank you. Any way to decode it?

 

[nd5y]

Very interesting thank you. Any way to decode it?

Probably not. You would need to know what protocol and software their radio modems use and what software was sending/receiving the modem data. There are some ham radio programs that will decode AX.25 packet, plain ASCII and some other formats but good luck with that on what is probably some commercial SCADA product. Even if you were able to decode it you would probably just get a stream of hex and you wouldn't even know if it was encrypted or not.

 

[footage]

Same xmsns on same channel in the central San Francisco Bay area, if it's any help.