AR15.Com Archives
 How to listen to scrambled police channels.
S_A_C  [Member]
2/25/2013 8:34:54 PM
So something was happening next door, so I tried to listen in on the scanner to see what was happening, only to find out that the local police use a scrambler, so all I got was garbeled noises, and clicks, is there any way to in unscramble the signal?
CaptainPatSmith  [Member]
2/25/2013 8:37:59 PM
Step one.... Get job with local police department.
Step two.... Listen to issued police radio.
WilliamGray  [Team Member]
2/25/2013 8:39:38 PM
They probably switched to the APCO-25 protocol like all the other PDs in the country. Get a digital scanner. They can be had for around $3-400 at RadioShack.

http://www.scannermaster.com/Digital_Police_Scanner_Radios_s/269.htm
Thoughtcrime  [Team Member]
2/25/2013 8:40:07 PM
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system
uafgrad  [Life Member]
2/25/2013 8:41:34 PM
Most of our departments have gone to encrypted transmissions
WilliamGray  [Team Member]
2/25/2013 8:42:02 PM
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.
mikecnorthwest  [Member]
2/25/2013 8:42:15 PM
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.
scottedward58  [Team Member]
2/25/2013 8:42:20 PM
Tell us exactly where you are and we can help.
WilliamGray  [Team Member]
2/25/2013 8:45:48 PM
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


The new APCO-25 radios are data transmissions. The audio from the mic is encoded in a digital codec, then transmitted as data, with some other info included in the packets, then it is decoded on the receiving side and converted back to audio, with some digital information displayed on the LCD if so equipped.
WilliamGray  [Team Member]
2/25/2013 8:48:31 PM
JINXR  [Team Member]
2/25/2013 8:58:41 PM
Most analog scrambled audio is just inverted audio. There is software out there that can de-scramble it. Just have to have a full duplex sound card.

S_A_C  [Member]
2/25/2013 9:01:44 PM
Originally Posted By WilliamGray:
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.


That's what I was hearing, a garbled word, or part of one, then a bunch of clicks, another garbled word fragment, then more clicks, and so on.
J75player  [Team Member]
2/25/2013 9:01:50 PM
Originally Posted By CaptainPatSmith:
Step one.... Get job with local police department.
Step two.... Listen to issued police radio.


WilliamGray  [Team Member]
2/25/2013 9:04:06 PM
Originally Posted By S_A_C:
Originally Posted By WilliamGray:
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.


That's what I was hearing, a garbled word, or part of one, then a bunch of clicks, another garbled word fragment, then more clicks, and so on.


Then that could be trunking. What Police department? I can tell you real quick what they are using.
cmjohnson  [Team Member]
2/25/2013 9:08:02 PM
If they're only digital, you can get a scanner at your local Radio Shack that'll pick them up.

If they're encrypted, you're flat out of luck. It's illegal to decrypt encrypted transmissions without approval, even assuming you COULD.


S_A_C  [Member]
2/25/2013 9:08:11 PM
Originally Posted By WilliamGray:
Originally Posted By S_A_C:
Originally Posted By WilliamGray:
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.


That's what I was hearing, a garbled word, or part of one, then a bunch of clicks, another garbled word fragment, then more clicks, and so on.


Then that could be trunking. What Police department? I can tell you real quick what they are using.


Eastpointe MI, but I was listening to the Macomb County channel (multiple departments use it), I think that's the one Easpointe uses.
webtaz99  [Team Member]
2/25/2013 9:10:05 PM
"Citizen, pick up that can..."
hourglassing  [Team Member]
2/25/2013 9:11:59 PM
If you just CALL Krispey Kreme, they'll tell you when the next fresh batch is due out.
brassburn  [Team Member]
2/25/2013 9:15:37 PM
the-fly  [Team Member]
2/25/2013 9:16:02 PM
Originally Posted By S_A_C:

Eastpointe MI, but I was listening to the Macomb County channel (multiple departments use it), I think that's the one Easpointe uses.


Just looked it up, they use an APCO-25 system. You need a scanner that can decode that type of system, and if they use encryption on top of that (unlikely, but there are a few departments that do), you're hosed.
WilliamGray  [Team Member]
2/25/2013 9:18:34 PM
Originally Posted By S_A_C:
Originally Posted By WilliamGray:
Originally Posted By S_A_C:
Originally Posted By WilliamGray:
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.


That's what I was hearing, a garbled word, or part of one, then a bunch of clicks, another garbled word fragment, then more clicks, and so on.


Then that could be trunking. What Police department? I can tell you real quick what they are using.


Eastpointe MI, but I was listening to the Macomb County channel (multiple departments use it), I think that's the one Easpointe uses.


It looks like they are on a trunked APCO-25 system. Here is all the info if you decide to get a digital scanner.


http://www.radioreference.com/apps/db/?sid=100
WilliamGray  [Team Member]
2/25/2013 9:20:30 PM
Originally Posted By the-fly:
Originally Posted By S_A_C:

Eastpointe MI, but I was listening to the Macomb County channel (multiple departments use it), I think that's the one Easpointe uses.


Just looked it up, they use an APCO-25 system. You need a scanner that can decode that type of system, and if they use encryption on top of that (unlikely, but there are a few departments that do), you're hosed.


I belive he was listing to a state wide trunked apco-25 system. He will need a digital scanner, plus all of the trunking info I gave him in a previous link.
SamBram  [Team Member]
2/25/2013 9:38:11 PM
You can listen to most counties online. I use an app on my Android called Scanner Radio.
Packin  [Member]
2/25/2013 9:47:36 PM
Some departments use speech scramblers.

You can get a scrambler / descrambler here. Dont know the legalities of listening to scrambled scanner messages

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=SS70C
offctr  [Team Member]
2/25/2013 9:48:48 PM
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)
Originally Posted By WilliamGray:
Originally Posted By Thoughtcrime:
I doubt it is scrambled.

They are probably using trunked radio.

http://en.wikipedia.org/wiki/Trunked_radio_system


If they were just using trunking, you would hear plain audio on an analog scanner, but you would only hear parts of the conversation as the radio jumped frequencies between transmissions.


the-fly  [Team Member]
2/25/2013 10:12:21 PM
Originally Posted By Packin:
Some departments use speech scramblers.

You can get a scrambler / descrambler here. Dont know the legalities of listening to scrambled scanner messages

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=SS70C


Only works for analog style scrambling, which to the best of my knowledge is NOT used by any sort of LE.
the-fly  [Team Member]
2/25/2013 10:14:18 PM
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




WilliamGray  [Team Member]
2/25/2013 10:52:55 PM
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




http://www.greamerica.com/images/PSR-800LG.jpg



Yup. I have a RadioShack 106 that will decode APCO-25. Police will tell you their system is encrypted because they think it is. 95% of them are not. They only encrypted frequencies I have found were tac channels. Most do not encrypt because of cost and/or interoperability between agencies.
Packin  [Member]
2/25/2013 11:47:56 PM
Originally Posted By the-fly:
Originally Posted By Packin:
Some departments use speech scramblers.

You can get a scrambler / descrambler here. Dont know the legalities of listening to scrambled scanner messages

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=SS70C


Only works for analog style scrambling, which to the best of my knowledge is NOT used by any sort of LE.


County Sheriff 2 counties over uses it, where as everyone else around here has gone trunked

TheGrayMan  [Life Member]
2/25/2013 11:55:29 PM
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


That site just lit up Malware warnings in Google, and in my Antivirus software.
Codyboy  [Member]
2/26/2013 12:02:28 AM
ten Paul twenty two, switch to TAC2.

Clear.

fiver  [Life Member]
2/26/2013 12:06:08 AM

Originally Posted By TheGrayMan:
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


That site just lit up Malware warnings in Google, and in my Antivirus software.

That's bizzare.... Radioreference has long been a mainstay and rock solid. I wonder if they got hacked or domain hijacked or something, shit's all fucked up over there.

Ironhandjohn  [Member]
2/26/2013 12:07:16 AM
Originally Posted By TheGrayMan:
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


That site just lit up Malware warnings in Google, and in my Antivirus software.




Mine, too.
DesertDog1  [Team Member]
2/26/2013 12:07:17 AM
Originally Posted By WilliamGray:
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.



http://www.greamerica.com/images/PSR-800LG.jpg



Yup. I have a RadioShack 106 that will decode APCO-25. Police will tell you their system is encrypted because they think it is. 95% of them are not. They only encrypted frequencies I have found were tac channels. Most do not encrypt because of cost and/or interoperability between agencies.


Most state and local agencies are not encrypted but some of the federal agencies are.
phurba  [Life Member]
2/26/2013 12:09:15 AM
Assuming you have a receiver that can handle encrypted comms (not cheap or requires an SDR + a good understanding of DSP to write a receiver for it or SDR + friends who do) you can file a FOIA request for the keys.
c439  [Member]
2/26/2013 12:10:44 AM
You could Prbly call and inquire on the nature of the call
S_A_C  [Member]
2/26/2013 1:25:52 AM
Originally Posted By WilliamGray:
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such system




http://www.greamerica.com/images/PSR-800LG.jpg



Yup. I have a RadioShack 106 that will decode APCO-25. Police will tell you their system is encrypted because they think it is. 95% of them are not. They only encrypted frequencies I have found were tac channels. Most do not encrypt because of cost and/or interoperability between agencies.


Is there anything that can decrypt actual encrypted signals?
JINXR  [Team Member]
2/26/2013 2:43:57 AM
Originally Posted By the-fly:
Originally Posted By Packin:
Some departments use speech scramblers.

You can get a scrambler / descrambler here. Dont know the legalities of listening to scrambled scanner messages

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=SS70C


Only works for analog style scrambling, which to the best of my knowledge is NOT used by any sort of LE.


My local Leo does

the-fly  [Team Member]
2/26/2013 11:31:44 AM
Originally Posted By S_A_C:

Is there anything that can decrypt actual encrypted signals?


Sure, but the problem is getting the decryption keys.
WantsToBelieve  [Member]
2/26/2013 11:33:45 AM
If it's just APCO 25, you can get a scanner that will handle it.
bg10  [Team Member]
2/26/2013 11:35:30 AM
Originally Posted By webtaz99:
"Citizen, pick up that can..."


Choking_Hazard  [Team Member]
2/26/2013 11:35:56 AM
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




http://www.greamerica.com/images/PSR-800LG.jpg


For the low low price of $500
phurba  [Life Member]
2/26/2013 11:53:09 AM
Originally Posted By Choking_Hazard:
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




http://www.greamerica.com/images/PSR-800LG.jpg


For the low low price of $500


Digital trunking scanners are friggin expensive... no way around that. Other than rolling your own with an SDR. There's a lot going on inside that unit.
TheGrayMan  [Life Member]
2/26/2013 12:02:20 PM
Originally Posted By S_A_C:

Is there anything that can decrypt actual encrypted signals?


Not without the crypto key.
The_Beer_Slayer  [Site Staff]
2/26/2013 12:03:20 PM
Originally Posted By TheGrayMan:
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


That site just lit up Malware warnings in Google, and in my Antivirus software.


it's legit i use it almost weekly.
Choking_Hazard  [Team Member]
2/26/2013 12:03:45 PM
Originally Posted By The_Beer_Slayer:
Originally Posted By TheGrayMan:
Originally Posted By mikecnorthwest:
Or the frequency you were monitoring is used for data transmissions, not voice. Radioreference.com is the best source of radio system information. Search for your county or local system.


That site just lit up Malware warnings in Google, and in my Antivirus software.


it's legit i use it almost weekly.


Same, use it almost everyday.
S_A_C  [Member]
2/26/2013 4:26:32 PM
Originally Posted By phurba:
Originally Posted By Choking_Hazard:
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




http://www.greamerica.com/images/PSR-800LG.jpg


For the low low price of $500


Digital trunking scanners are friggin expensive... no way around that. Other than rolling your own with an SDR. There's a lot going on inside that unit.


What's an SDR?
phurba  [Life Member]
2/26/2013 4:30:27 PM
Originally Posted By S_A_C:
Originally Posted By phurba:
Originally Posted By Choking_Hazard:
Originally Posted By the-fly:
Originally Posted By offctr:
they are trunked but they are digital --and around here only the state police and either Motorola or Harris whomever built the system know the encoding algorithm. So essentially they are encrypted but its more like trying to listen to a nextel radio or digital phone signal on an analog scanner. I don't think there is a scanner built that can deal with all the variables fast enough to decode the signal back to intelligible audio -its essentially an EDACS system on steroids (Google opensky)



No offense but your info is out of date. There's plenty of scanners now that can decode in real time a digitally trunked system. As long as the system in question is not using an encryption routine on top of the digital encoding, its not difficult at all to monitor such systems.




http://www.greamerica.com/images/PSR-800LG.jpg


For the low low price of $500


Digital trunking scanners are friggin expensive... no way around that. Other than rolling your own with an SDR. There's a lot going on inside that unit.


What's an SDR?


Software Defined Radio.