voice descrambling software

[scannergoduk]

hi all im after some software to decsramble a voice transmission on my scanner which i found its possible that it may be the police but i duno
i want to descramble the transmission and work out what it is
i pick it up on 478.450mhz uhf sounds like its on the ssb or similar i pick the signal up on my netset scanner but not my uniden for some strange reason
any help would be grateful cheers

[CalgaryToad]

Ummm. I think you should read over the FCC regs again man. Its super super duper illegal to decode anything scrambled. You wont get any help here. You have been warned, continue at your own risk :-)

Ps: I would dare to say over half of this forum is filled with the following, careful what you say or do.

1.Police
2.Fire
3.Military
4.Government
5.Public Safety

[gmclam]

What you are hearing is not actually "scrambled" or "encrypted". It is a process called "speech inversion". There are a few programs out there which can do this on your PC, but they are not as good as hardware circuits which perform the same function. Check the wiki here and also try searching for speech or voice inversion and you'll find lots of stuff.

Here's a current thread on the topic:
http://www.radioreference.com/forums...ad.php?t=13070

[CalgaryToad]

I may have been wrong about not getting help doing this but its still not a good thing to do in my books.

The laws concerning decoding encrypted radio signals here in Canada is illegal just like in the states. Where the law gets kinda fuzzy is what constitutes encryption?

Industry Canada's definition of encryption and it's laws are here:

http://laws.justice.gc.ca/en/R-2/99354.html

Their definition of encryption is:

2. "encrypted" means treated electronically or otherwise for the purpose of preventing intelligible reception.

If you go further down the document, in section 9 you will find this:

9. (1) No person shall

(c) decode an encrypted subscription programming signal or encrypted network feed otherwise than under and in accordance with an authorization from the lawful distributor of the signal or feed.

(d) operate a radio apparatus so as to receive an encrypted subscription programming signal or encrypted network feed that has been decoded in contravention of paragraph (c).

Subsections C and D clearly state that decoding signals is prohibited.

[Dewey]

478.450 sounds like an image. I'm not familiar with a "Netset scanner", but if it's an older scanner, you're probably hearing an image... which also explains why you're not hearing it on the Uniden. On older scanners, you could sometimes receive out of band signals (images) by multiplying the image by 2, and adding/subtracting the sum to/from the frequency (common IF frequnecies were 10.6, 10.7, & 10.8). Bottom line, using the Uniden, try searching 21-22 MHz above or below the frequecy and see if you get anything when the netset is active. You may also find that you are now hearing a "cleaner" signal.

Finally, yes, you don't want to decode encrypted signals, but all digital signals are not encrypted. It was easy to tell the old DES encrypted signals on conventional frequencies, because they sounded like "white noise" (an open squelch) with a low volume, high pitched beeeeep at the end. In the "good ol' days", signals where "masked" by inversion... they sounded a lot like a drunk Donald Duck. There were programs out there that would re-invert the signal, but I haven't heard inversion used on the public service frequencies in at least 15 years.

Dewey

[gmclam]

Originally Posted by Dewey

Finally, yes, you don't want to decode encrypted signals, but all digital signals are not encrypted.

I believe the OP is monitoring an analog signal, not a digital signal.

There were programs out there that would re-invert the signal, but I haven't heard inversion used on the public service frequencies in at least 15 years.

There are not only programs out there to uninvert the audio, but hardware, assembled, tested and ready to go. I still hear plenty of speech inversion out here in northern California. It just depends on where you are, and what or who you are listening to. Not every agency can afford the latest greatest (digital) encryption and/or radios.

[cpuerror]

I think those laws were more meant to illegilize pirate satellite. The laws were created as our government once again immediatley rolls over and does whatever a big american corporation tells it to do. But I suppose "network feed" could be construed as a public safety network feed.

[brandon]

the OP in the UK so I don't think the FCC rules are of any worry.

[n2mdk]

Originally Posted by brandon

the OP in the UK so I don't think the FCC rules are of any worry.

The UK laws are even worse than ours are. From what I understand listening to SW numbers stations in the UK is technically illegal. Crazy I know.
http://www.statutelaw.gov.uk/content...tdocid=2926035