"Inversion Scramble" vs. "rolling code"

[gmclam]

[a] station operator must not communicate ... coded messages or messages with hidden meanings.

This one is laughable to me. There are so many codes out there I could not think of them all right now - morse code, 10 codes, 11 codes, etc. Hidden meanings, LOL. I sure do hear a lot of that on my scanners.

 

[MikeSD]

This one is laughable to me. There are so many codes out there I could not think of them all right now - morse code, 10 codes, 11 codes, etc. Hidden meanings, LOL. I sure do hear a lot of that on my scanners.

I believe the FCC specifically allows 10 codes and tone codes with a functional purpose. But if you were to get on the air and say, 5732 5595 5855 1476 Z258 which represented a code you had cooked up, that would truely be a hidden meaning and coded message and would be illegal. Why it should be illegal, is beyond me. I can't imagine any logical reasoning that should make that illegal. About the only logical thinking that I can come up with is some ancient reasoning that the airways should be used only for legitimate uses and the presumption is that if you are using codes, you must be up to no good. That's really old thinking.

 

[East_Algoma]

Its funny how **some** want to SCRAMBLE simple frs or gmrs , and once there local PD goes and gets a DES system , THEY FREAK with a HOW DARE THEY DO THAT my poor P25 scanner I spent heaps of $$ on is now useless,,,,,BUT they still WANT THIER Comms Scrambled.....heheh

 

[kroenken]

Scrambling Compatibility

Okay so, I didn't see anyone here talking about scrambler compatibility. (If I missed it I do apologize.) I am trying to find out if, for example, a Motorola radio, such as the rdu2080, would be compatible with, lets say, a Relm RPU7500 radio. Both using the basic inversion voice scrambling. Would they be able to decode the signal from the other manufacturers product and communicate? I tried asking a Relm support tech but he couldn't answer it simply because he didn't know.

Any input would be great.. Thanks

 

[gewecke]

Okay so, I didn't see anyone here talking about scrambler compatibility. (If I missed it I do apologize.) I am trying to find out if, for example, a Motorola radio, such as the rdu2080, would be compatible with, lets say, a Relm RPU7500 radio. Both using the basic inversion voice scrambling. Would they be able to decode the signal from the other manufacturers product and communicate? I tried asking a Relm support tech but he couldn't answer it simply because he didn't know.

Any input would be great.. Thanks

IF they are both single inversion scrambling then they should be. This depends on which null points are selected in each radio.
If the values are close enough then maybe.

73,
n9zas

 

[ff-medic]

I don't consider "inversion" to be a form of scrambling. Think of eggs sunny-side up as being normal, flip them over for inversion, and scramble them for scrambling. In other words, to scramble, you really mix things up.

.

CORRECT - Speech inversion is not encryption

And there is equipment to buy to listen/monitor speech inversion radio transmissions.

AES / DES is the only way to go.

FF - Medic !!!

 

[kroenken]

RE Scrambling Compatibility

IF they are both single inversion scrambling then they should be. This depends on which null points are selected in each radio.
If the values are close enough then maybe.

73,
n9zas

Might you know of any web page where this is explained in detail? At work we use the Motorola RDU2080 radio and there are three scramble options available in these radios. My personal radio is a Relm RP7500 which has the scramble feature, on or off, no selection, no adjustment. Relm tech says they use an inversion of the sine wave to achieve scrambling. How does Motorola do it?

I am trying to consolidate radios.. Tired of carrying two to three radios..

 

[mancow]

I just created a yahoo group called TranscryptInternational. There is nothing there but feel free to sign up and we can start discussing them there. I have a few manuals that might help a bit too that I can upload. I know the 460 series will allow fix inversion interoperability and you can change the split points. There is a cross matrix in the manual that shows what freq points correspond to several other manufacturers like MXCOMM.

 

[prcguy]

Speech inversion is indeed a form of encryption although not a very good one. Encryption is any means of transforming information to make it unreadable to anyone except those possessing special knowledge, per Wikipedia and other sources. BTW, I have a hand held scanner with a built in speech inversion descrambler so its really not an effective means of encryption these days.

Rolling code scrambling is very effective and just a better way to implement speech inversion encryption.
prcguy

CORRECT - Speech inversion is not encryption

And there is equipment to buy to listen/monitor speech inversion radio transmissions.

AES / DES is the only way to go.

FF - Medic !!!

 

[SCPD]

I think this whole thread should be scrambled!

 

[gewecke]

I think this whole thread should be scrambled!

Yep, nothing worse than splitting hairs. :roll:


73,
n9zas

 

[traffic27fl]

Just stumbled onto this thread tonight. Here are the relevant citations from a Notice of Apparent Liability (FCC File number EB-08-SE-819) adopted on June 23, 2009 and released on June 25, 2009 referring to a fine of $21,000 against Midland Radio for selling radios capable of encoding modulation. In the notice the commission cited Part 95.183 (a)(4) which says " A station operator must not communicate: coded messages or messages with hidden meanings ("10 codes) are permissable;. The bottom line is that the technology is irrelevant. If a transmission is not monitorable by anyone with standard equipment capable of monitoring the frequency in standard modulation, it is non-compliant.



ulation.

 

[gewecke]

Just stumbled onto this thread tonight. Here are the relevant citations from a Notice of Apparent Liability (FCC File number EB-08-SE-819) adopted on June 23, 2009 and released on June 25, 2009 referring to a fine of $21,000 against Midland Radio for selling radios capable of encoding modulation. In the notice the commission cited Part 95.183 (a)(4) which says " A station operator must not communicate: coded messages or messages with hidden meanings ("10 codes) are permissable;. The bottom line is that the technology is irrelevant. If a transmission is not monitorable by anyone with standard equipment capable of monitoring the frequency in standard modulation, it is non-compliant.



ulation.

Yep, and is a moot point since motorola was allowed to market GMRS/FRS radios with inversion scrambling as a feature but interestingly, they were not cited that I ever found. So I have to wonder why midland would be cited, and moto was not? :roll:

73,
n9zas

 

[East_Algoma]

I agree

close enough is ok in Golf...( Not my game tho ..Yikes ) But in the world of Encryption , there is no close...must be exact...or no go...

I have Uniden FRS radios I bought....The only reason I bought them is because they both had Voice Inversion on them.

A short while later , the FCC pulled all models with this capability .

I reside in Canada where such rules do not exist ( YET ! )

Its hard to find a center Freq to use a Inversion decoder on it....I cant get a stable lock on the center Freq...

Cobra , Midland and Uniden all had models that have Inversion on them.

My 2 Radio I might sell....or trade for a SWR with bfo - 150 - 30.00 type thing

IF they are both single inversion scrambling then they should be. This depends on which null points are selected in each radio.
If the values are close enough then maybe.

73,
n9zas