How to descramble a VHF freq.

[CoCo]

Is there a way to descramble a VHF freq. 155.580. When the dept used to talk on this
channel, it was ok and u could hear them. Now they have scrambled it out. I have a BCD396T scanner.
They are still on the same freq., it is just scrambled out.

 

[SLWilson]

Legally?

Not legally. Once they scramble it, you're better off giving up on listening to it!

Steve/KB8FAR

 

[CoCo]

But is there a way to descramble?

 

[Spec]

Depends on the type of encryption being used.

 

[CoCo]

The PD is using Motorola radios and they are on VHF. I don't know what
type encryption they use. I am new to this. Is there several different types for that freq. range?

 

[mancow]

What does it sound like?

The band such as Vhf or Uhf doesn't mean anything. It could be Securenet CVSD encrypted voice or Midian or Transcrypt type analog inversion or even P25 CAI digital with encryption applied.

In the end it doesn't really matter. The only thing that can be easily "decoded" is simple single split point audio inversion.

I wouldn't spend much time dwelling on it. Accept it as the frustration it is and move on.

 

[CoCo]

Thanks alot. I'll do that.

 

[pitcockm]

What system are you trying to listen to?

 

[kma371]

Is there a way to descramble a VHF freq. 155.580. When the dept used to talk on this
channel, it was ok and u could hear them. Now they have scrambled it out. I have a BCD396T scanner.
They are still on the same freq., it is just scrambled out.

It may help to tell us what agency your talking about and where your located

 

[CoCo]

The agency is Hammond, La. PD.

 

[jhooten]

But is there a way to descramble?

If there was it would be kind of useless to encrypt in the first place, now wouldn't it?

 

[WooBuff]

It sounds like old style voice inversion. They are now the only agency in the parish using any type of encryption, which is odd based upon the need for interoperability with the S.O. and LSP units working the area.

It started on their talk channel a couple of weeks ago, and yesterday it started on the dispatch channel as well.

 

[bpckty1]

Sounds like they don't want the "food police" knowning where they get their eats.

 

[CoCo]

hooten, why would it be useless to encrypt. If it works and I can hear them, I think it
would be worth decoding. I will speak with some that knows how to do it. Thanks anyway.

 

[jhooten]

If just anybody, you, me, the criminals could easily decrypt it... oh never mind.

If they are using simple voice inversion there are hobby kits on the market to do the job. Check Ramsey's web site. Any other type of encryption system and you are going to need one of Cray's finest of the services of the NSA to do it in real time.

Yes it can be done. IF you have lots of money and the right resources. When you do it and you get caught ask them if you can get assigned to my work crew. I am told I am a good Boss to work for.

 

[CoCo]

Thanks, I'll keep that in mind. I have some one working on it and it should be done on Monday. I am told it is a very simple way.

 

[RayAir]

I won't get into the legalities of decoding a scrambled message, but the fact is all analog scrambling whether it is fixed inversion or a Transcrypt 460 can all be decoded. The higher end analog scramblers not in real time of course. All analog scrambling can be analyzed and there are numerous techniques that can be used to attempt to restore it to normal voice once the type of scrambling is identified. If a department wants true communications security then they must use digital encryption (white noise), 128-bit AES or higher. 56-bit Securenet is probably good enough for most users. I wouldn't use it for organized crime or drug cartel surveillance though.

 

[steener]

Scrambling

Ramsey Electronics sells a kit for around $40 that you can use for scrambling/descrambling communications.

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

It has input and output so that you can use it for your own communications setup

Regards
Paul

 

[WooBuff]

It appears that they are using speech inversion at 6400 Hz. The Ramsey kit uses 3300 Hz as the inversion frequency.

 

[kevins669]

It appears that they are using speech inversion at 6400 Hz. The Ramsey kit uses 3300 Hz as the inversion frequency.

So hook two kits together??? Ohhh wait... that would be too many hertz....