Signal ID question

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Markb

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Hello Group,

When I tune in 868.9875, I can occasionally hear a telemetry-type signal and it appears to cover a wide area. I've heard it from North Orange County and up into downtown LA. It sounds like a regular data pulse with no variation - almost like some sort of timing signal. Anyone have any idea as to what this may be?
I've listened to samples of digital signals without being able to pin it down. Also, the only users licensed for this frequency in the area are Orange County and The State, apparently at the Lancaster and Chino prisons as well as the prison(?) in Whittier (on Whittier Blvd, can't remember the name or use of the place). Thanks in advance.

Mark
 

monitor142

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I'm in South OC Mark....I'll listen up here. I'm pretty sure that being that is 800 Firemars that there should not be any data being transmitted and the OC and CA licenses are to cover the Firemars all around OC and the State in general.

-M142


Hello Group,

When I tune in 868.9875, I can occasionally hear a telemetry-type signal and it appears to cover a wide area. I've heard it from North Orange County and up into downtown LA. It sounds like a regular data pulse with no variation - almost like some sort of timing signal. Anyone have any idea as to what this may be?
I've listened to samples of digital signals without being able to pin it down. Also, the only users licensed for this frequency in the area are Orange County and The State, apparently at the Lancaster and Chino prisons as well as the prison(?) in Whittier (on Whittier Blvd, can't remember the name or use of the place). Thanks in advance.

Mark
 

K6CDO

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Hanover Co. VA
Hello Group,

When I tune in 868.9875, I can occasionally hear a telemetry-type signal and it appears to cover a wide area. I've heard it from North Orange County and up into downtown LA. It sounds like a regular data pulse with no variation - almost like some sort of timing signal. Anyone have any idea as to what this may be?
I've listened to samples of digital signals without being able to pin it down. Also, the only users licensed for this frequency in the area are Orange County and The State, apparently at the Lancaster and Chino prisons as well as the prison(?) in Whittier (on Whittier Blvd, can't remember the name or use of the place). Thanks in advance.

Mark

It sounds to me like you are hearing an image or an adjacent AT&T cell signal from above 869.0000. 868.9875 is FIREMARS, a statewide Fire/EMS Mutual Aid channel. The State is the license holder. The reason you don't see any more licenses in L.A. County is LAFD is the only local fire agency on 800 in the County, and only has the channel in their vehicles.
 

Markb

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Okay guys, I apologize. I meant 868.9625. Sheesh!:confused: I should get my info straight next time!
 

Mick

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868.9625 is part of the Orange, County of (Public Safety) TRS SID 6C3F Site 0015 & 0016:
Orange, County of (CCCS - Public Safety) Trunking System, Orange County, California - Scanner Frequencies

Maybe you're hearing some of the 20K0F1D, 20K0F2D emissions from Culver City's WQFT346 license, it could be an MDT for their Fire Dept., or for integrated Computer Aided Dispatch/ Automated Vehicle Location (CAD/AVL)


Okay guys, I apologize. I meant 868.9625. Sheesh!:confused: I should get my info straight next time!
 
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Markb

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I found what I was looking for. It must be Culver City's MDC/MDT's. The modulation scheme is Galdalf Technologies' Mobile Data. Sounds like this:

http://www.kb9ukd.com/digital/152.42-taxi.wav

Thanks guys for the input.

Mark

BTW, this guy has a ton of audio samples of digital signals if you ever wonder exactly what you are hearing......
 
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