Sutter Sheriff Encryption?

[scannerboy02]

Anyone happen to know if Sutter Sheriff run encryption on some of the radios?

I noticed a lot of hissing and scratching on 460.0750 CTCSS 118.8 and 460.5000 CTCSS 118.8 while they were searching for the missing 14 year old. I hear this from time to time but it increased big time over the past few days.

 

[Sac916]

When I lived in Yuba County I monitored Sutter SO a lot - They use voice inversion which was easily monitored via my AOR8200 with VI card

 

[cousinkix1953]

When I lived in Yuba County I monitored Sutter SO a lot - They use voice inversion which was easily monitored via my AOR8200 with VI card

I have some schematics, that explains to build one of those Donald Duck scramblers on a breadboard. It's powered by a 9 volt battery and plugged into the external speaker or headphone jack. You can assemble this project inside of a Radio Shack speaker box and put a 10K ohm pot on the front as the clarifier.

Not much use for one around here any more. What little encryption I hear is the digital type.

Expect to hear more scrambling up in Mendicino county. The hippies are watching the CAMP agents and reporting active marijuana raids to the local FM station. A criminal can get quite a bit of information from listening to KMUD. They don't need scanners any more.

Oh yes, interfering with the police and blabbing what you hear on a police scanner is illegal; but nobody got busted, after the sheriff went public with this information. It was in the San Francisco Chronicle; so you know the FCC heard about it too...

 

[EMT-Pat]

I noticed a lot of hissing and scratching on 460.0750 CTCSS 118.8

I can't comment on what you heard because I didn't hear it, but I have heard the 460.075 repeater getting keyed up with nothing but static for long lengths of time on more than one occasion, so if nobody is talking, I wouldn't think it was anything more than interference or the like.

I have never heard Sutter SO use anything other than occasional voice inversion.

 

[gmclam]

Voice inversion

I've only been monitoring Sutter (& Yuba) Sheriff at night after things locally die down a bit. In recent times I have not heard any non-vocal transmissions.

but I have heard the 460.075 repeater getting keyed up with nothing but static for long lengths of time on more than one occasion

hmmmm ... this is what I get on the FBI channels when they are talking. That IS a form of digital.

I have some schematics, that explains to build one of those Donald Duck scramblers on a breadboard

Yeah you can find them all over the Internet. They key is one IC that mixes two signals. but you can also use software on your PC (with your scanner audio connected to your PC) to do the same thing.

 

[cousinkix1953]

I've only been monitoring Sutter (& Yuba) Sheriff at night after things locally die down a bit. In recent times I have not heard any non-vocal transmissions.

hmmmm ... this is what I get on the FBI channels when they are talking. That IS a form of digital.

Yeah you can find them all over the Internet. They key is one IC that mixes two signals. but you can also use software on your PC (with your scanner audio connected to your PC) to do the same thing.

The simple ones used an 8 pin Motorola LM380N, which was only a 2 watt audio amplier. Everything else was common diodes resistors and junper wires.

A later model intended for use on a real radio transceiver used a 16 pin XR Systems chip that resembled those used in popular CB radios with upstairs/downstairs channels in them...

 

[EMT-Pat]

hmmmm ... this is what I get on the FBI channels when they are talking. That IS a form of digital.

I think I know what you mean about the FBI, but I don't think Sutter SO is doing digital on .075. It was a long time ago the first time I heard it happen, but when the repeater was being continuously keyed up, the dispatcher got on and said something along the lines of "is somebody trying to talk to dispatch." I guess it's possible but I'm too lazy to check all of the licenses for emission types. ok ok... i just checked WPVY862 and all of the emissions are F3E. I don't know if there are others.

 

[avtarsingh]

the rptrs there are pretty crappy and system noise desense and other crap hoses itself and it keys up at times on its own from interference

sutter buttes isnt a noise friendly site with so many heavy hitters up there

 

[gmclam]

The simple ones used an 8 pin Motorola LM380N, which was only a 2 watt audio amplier. Everything else was common diodes resistors and junper wires...

LOL. The LM380 is just an audio amplifier. It is not a 'required' component because you can amplify externally, etc.

The key component would be called a "double balanced mixer". You could use a Philips SA602A or NE602 (older part number for the same thing) for example.

What happens is that the audio on the broadcast end is mixed with some frequency. When you mix two signals you get their SUMS and DIFFERENCES. So let's use 4000 cycles for example. When 1000 cycles of audio is mixed, you end up with 3000 & 5000 cycles. When 3000 cycles is mixed you get 1000 cycles and 7000 cycles. But the upper frequencies are limited (filtered). On the receive end you reverse the process. Note that the exact frequency being mixed varies and does not have to be a specific exact value.