Voice Inversion HELP

[scanmike]

The RR database states that a county in my area of Mississippi, Marion County, may use voice inversion sometimes. Not familiar with this term. What is voice inversion? They are all VHF high band frequencies. How will it affect monitoring this county?

 

[wmbio]

Voice inverson

In simple terms, scrambled audio, the voice sounds like the worst donald duck sound you can imagine. There are several forms of voice inversion, simple to complicated, most all can be rendered intellible by the right soft or hardware.

 

[KR4BD]

Years ago, you could buy a "blackbox" device that would descramble voice inversion scrambling. They were connected "in line" to the scanner's speaker wiring. These devices are now considered illegal to own, but there are some still around. Essentially voice inversion makes low audio frequencies "high" and higher pitched audio frequencies "low". It does sound like Donald Duck before it is unscrambled. I bought one back in the 1970's and it worked well at the time.

 

[kingpin]

The RR database states that a county in my area of Mississippi, Marion County, may use voice inversion sometimes. Not familiar with this term. What is voice inversion? They are all VHF high band frequencies. How will it affect monitoring this county?

I'm not going to play RF police but it is against the law to unencrypt these transmissions. They are scrambled for a reason. However on the other side of the cain, there is free software on the internet called "Voice Inverter" that will convert the transmission back to intelligable audio. Works well. PM me if you can't find it after a google search. It's out there.

 

[gewecke]

Ramsey and don noble electronics are two co. which used to market descramblers
which would easily decode most single inversion traffic.If the the radios are analog.
Good luck.

 

[mike_s104]

I'm looking at the Ramsey model now...

model # SS-70

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

 

[Al42]

There's a difference between encrypted (illegal to monitor) and voice inversion (not illegal to monitor). Voice inversion is no more "encryption" than SSB is (which voice inversion sort of is).

 

[jred184]

This is how a simple voice inversion circuit is made. I am going to build one and test it out on some business band radios, not use it to decrypt police transmissions.

 

[datainmotion]

http://www.personainternet.com/~northscan/files.html

Certain AOR and Trident scanners offer an optional voice inversion feature.

 

[jred184]

I'm looking at the Ramsey model now...

model # SS-70

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

I just got mine in today. Next week I will build the circuit. I had audio recordings that were inverted, so I plugged the computer and a speaker up to the SS70C and played them.
Worked like a charm. VERY COOOOOOOOOOL!!!