Op25 and deinvert

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JAMESELD

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Can someone help me i get scramble voice on op25 but only static on deinvert what could this be?
 

boatbod

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Can someone help me i get scramble voice on op25 but only static on deinvert what could this be?
Not much to go from with that description. Can you elaborate (a) what you are trying to receive (b) what setup(s) and command lines you are running. Do you have the "--no-crypt" command line option turned on?

You do know that nobody is using old school voice inversion on P25 because the audio is fully digital using DVSI's AMBE/AMBE+2 codecs?
If encryption has been turned on (as you might find for many LEO tgids these days) you're not going to be able to reverse it easily.
 

JAMESELD

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Hi im using ubuntu 18.04 with run command for op25
./r44c.py --args 'rtl -N 'LNA:47 -S 2400000 -f420.2875e6 -o -2 -T trunk.tsv -V -2 -U 2> start.2

And run command for deinvert im using is
rtl_fm -M fm -f 420.2875M -s 12k -g 50 -l 70 | ./src/deinvert -r 12000 -p4 |\play -r 12 -c 1 -t .16-
On oo25 I can hear voice but it scrambled and the on deinvert I just get Static
Any help would be appreciated
 

boatbod

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Hi im using ubuntu 18.04 with run command for op25
./r44c.py --args 'rtl -N 'LNA:47 -S 2400000 -f420.2875e6 -o -2 -T trunk.tsv -V -2 -U 2> start.2

And run command for deinvert im using is
rtl_fm -M fm -f 420.2875M -s 12k -g 50 -l 70 | ./src/deinvert -r 12000 -p4 |\play -r 12 -c 1 -t .16-
On oo25 I can hear voice but it scrambled and the on deinvert I just get Static
Any help would be appreciated
Try this for op25 and report back.
./rx.py --args 'rtl -N 'LNA:39 -S 960000 --no-crypt -X -2 -T trunk.tsv -V -2 -U 2> stderr.2
 

JAMESELD

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Jan 31, 2020
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Not much to go from with that description. Can you elaborate (a) what you are trying to receive (b) what setup(s) and command lines you are running. Do you have the "--no-crypt" command line option turned on?

You do know that nobody is using old school voice inversion on P25 because the audio is fully digital using DVSI's AMBE/AMBE+2 codecs?
If encryption has been turned on (as you might find for many LEO tgids these days) you're not going to be able to reverse it easily.
Try this for op25 and report back.
./rx.py --args 'rtl -N 'LNA:39 -S 960000 --no-crypt -X -2 -T trunk.tsv -V -2 -U 2> stderr.2
Hi thank you for your help i don't get anything from that command any other ways
 

boatbod

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Hi thank you for your help i don't get anything from that command any other ways
"Dont get anything" simply meaning no voice being decoded, or meaning you see nothing happening on the terminal screen at all?

Grab a screen shot of the terminal after starting rx.py, preferably when there is an extra message or two showing down near the bottom where is says "Frequency ...".
 

JAMESELD

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I can hear voice but its scrambled

I can hear voice but its scrambled
I can not upload pic sorry

Now I have it working with that command but no sound and eecryipsin is coming up on right hand couner of screen
 

boatbod

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Now I have it working with that command but no sound and eecryipsin is coming up on right hand couner of screen
That's what I suspected.
Sorry to say but you're not going to be able to decode that encrypted transmission because it's digital encryption not voice inversion. Is this is military or law enforcement system?
 
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