mike_s104
Member
Anyone else heard encryption like this? I just started hearing it here.
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Fed Encryption
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MOTOROLANUT
Member
Very Odd, Have you heard this electronic distortion type sound for any long length of time?....30 or more seconds? I just wonder if it is really encryption or something else?
mike_s104
Member
Conventional. On that freq., I have heard both P25 and analog traffic in the clear in the past. Also, its different from the other analog (analog signal) encryption I've heard on that freq. Tomorrow if I have time, I will try to dig up on older recording of the encryption sample. So far I have nothing more in length then I posted with that encryption.
SOFA_KING
Member
I have never heard that type of data from P25. I have heard a full time data channel on the USCG, and seen the NAC to confirm it being P25, and it sounds nothing like that at all.
My guess??? Telemetry of some sort...maybe for remote alarming. The FBI used to have all sorts of stuff like that in the old days, but slower data rates.
What scanner was used?
My guess??? Telemetry of some sort...maybe for remote alarming. The FBI used to have all sorts of stuff like that in the old days, but slower data rates.
What scanner was used?
mike_s104
Member
Using a 396XT. It sounded like analog, so I set it to analog only and search for a tone...no CTCSS. Like I've said before, I'd heard both P25 and analog traffic in the past on the same freq.
From the transmitter's hang time at the end of your recording it seems to me that 167.4375 is a repeater output. So what is heard maybe getting in through the repeater's input frequency. If you know the input freq. you may want to monitor it. It's strange that no CTCSS is being encoded, in all the FBI repeater interefence cases I've heard, either the 167.9 or EOM tones were present.
ecps92
Member
mike_s104
Member
I don't think so.
ecps92
Member
It certainly [for a short clip] sounds like intermod getting into the input of the Repeater. How about a longer clip ?
SOFA_KING
Member
But if it is getting into the repeater, it needs a PL of 167.9. And if it is coming from the repeater, he should see the 167.9 PL on the scanner.
I say it is either on frequency data (not common, but I have heard the FBI do it), or an image on his scanner.
I say it is either on frequency data (not common, but I have heard the FBI do it), or an image on his scanner.
ecps92
Member
So many variables, to make many assumptions.
Could be a Dual Mode Rptr [P25 and Analog]
Maybe someone left the PL of the RX side [happens routinely]
Could be a Dual Mode Rptr [P25 and Analog]
Maybe someone left the PL of the RX side [happens routinely]
It could be intended data on a frequency12.5kHz either side of the repeater input resulting from poor or no frequency coordination.
This happened for years on an FBI repeater input of 165.9000 analog, ATF's channel 5 simplex 165.9125 analog CSQ would often interfere causing the three associated FBI repeater outputs to transmit semi intelligent voice with 167.9.
Anybody know the 167.4375 repeater input frequency?
Wondering if it might be FAA telemetry data audio.
This happened for years on an FBI repeater input of 165.9000 analog, ATF's channel 5 simplex 165.9125 analog CSQ would often interfere causing the three associated FBI repeater outputs to transmit semi intelligent voice with 167.9.
Anybody know the 167.4375 repeater input frequency?
Wondering if it might be FAA telemetry data audio.
mike_s104
Member
Again, in the past, I have heard P25 in-the-clear and encrypted traffic as well as analog in-the-clear and I believe encrypted (it sounds almost like static except for the squelch tail like in this sample). It is a repeater output.
fourthhorseman
Member
telemetry,you mean this sort of deal-e-o..
http://www.philly.com/inquirer/busi..._new_satellite-surveillance_radio_system.html
the newly online sat system for aircraft?
Could also be OTAR data.
(Over the air re-keying) Changing the encryption key on a radio.
They would send it without PL so the users wouldn't hear it.
Chuck
(Over the air re-keying) Changing the encryption key on a radio.
They would send it without PL so the users wouldn't hear it.
Chuck
Off topic, but I have to say this:
Gone are the days of the movie quotes,"fly below radar, we don't want to be caught!". :wink: Of course one flick of the switch can be written into the script. :lol: (in lieu of ground-based radar. Primary radar.)
CORTCHUBBY2007
Member
Well, I played it SEVERAL times then ran it thru an analyzer and compared it to actual encryption
and it isnt encryption. I agree that its intermod. Strong at that.
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I used to hear something similar (although not quite the same) on a US Customs frequency in San Diego back in the analog days. Not P25, Not OTAR, just some kind of digital noise and showed up with the 100.0 PL. Wish I had a recording of it still.
Speaking of federal encryption... this is my favorite type
Speaking of federal encryption... this is my favorite type
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