Cobourg PD Gone Encrypted

[VA3DBJ]

Voice inversion encryption just came up tonight on the Cobourg VHF channel. I am assuming the 800 trunk is the same as well.

 

[Jammin_Jay]

Should be a standard voice inversion carrier around 3.5 khz such as the others in Eastern Ontario. Is it straight voice inversion, or just select transmissions. Do you hear DTMF soundalike tones after the modulation for id purposes or a sqwauk at the beginning of the transmission when in the clear mode. Just curious how there set-up is. Still easy to decode and listen to. I'd be curious of the trunking transmission as well. Can any member in the Northumberland area verify this?

 

[sirsmiley]

just standard voice inversion? does it sound like a deep daffy duck voice you know those old 1980s 1990s scrambled tv channels sometimes too

 

[hemi]

Should be a standard voice inversion carrier around 3.5 khz such as the others in Eastern Ontario. Is it straight voice inversion, or just select transmissions. Do you hear DTMF soundalike tones after the modulation for id purposes or a sqwauk at the beginning of the transmission when in the clear mode. Just curious how there set-up is. Still easy to decode and listen to. I'd be curious of the trunking transmission as well. Can any member in the Northumberland area verify this?

Iam in the very north of Nortumberland, just outside of the trunking reception, but i go to Cobourg a lot so i will check it out.

 

[radioman253]

cobourg voice inversion up and running...

I heard them as well this evening and I can tell you that it sounds like sideband.
If you listened to it long enough you could almost start to discern this new "ducklike" quacking version of English. The audio seemed much clearer than that which I last heard Port Hope quacking on 142.245.
Not the rolling code sort of inversion with the metronome like time clicks (remember
city tv 453.7875 rolling code scambling?)
This should be able to be easily monitored with the right software or hardware.
There are circuits online that you could build if you could find the parts.
The one I saw had and NEC602 IC and an LM386 chip (for audio amp) as well as an audio xfmr.
I will try to build this as some point although I would be more likely to use it for the 900MHZ trunk stuff to test it out on, as Cobourg PD north VHF channel is only marginally receivable out here in Courtice (At some point they must have either reoriented their xmit antenna or dropped power because 142.485 used to boom in to this QTH).
. The nice part of building a circuit is that youre not tied to your PC, and the inherent RF interference that may result.
Has anyone built one of these circuits with success??

GH
in Courtice

 

[exkalibur]

If you listened to it long enough you could almost start to discern this new "ducklike" quacking version of English.

Back in the day (and maybe even still), sigint operatives were trained to decode this inversion scrambling in their head. That'd be a pretty neat trick to have. "No officer, my radio doesn't decode you guys at all..."

 

[motomeso]

The nice part of building a circuit is that youre not tied to your PC, and the inherent RF interference that may result.
Has anyone built one of these circuits with success??

GH
in Courtice

Or you could just buy one of the many Alinco model receiver / scanners that have the speech inversion descrambler built in.

 

[Jammin_Jay]

If the VHF frequency for Cobourg PD is voice inversion then what about the 800 Mhz trunking system. Just curious?
As for software. I have voice inversion descrambler for the computer sound card. You Enter 7000 in the frq and it u can tune it up or down to get the voice tuned in. but usually 3.3 khz to 3.5 khz is the norm for vi. Such an cheap and easy way for a police to so called "encrypt" there signals, but for many scanner hobbyist as myself, so easy to decode as well with software and other peripherals. But with budget for police board, what are u going to do? You only have so much to spend. But for those who know nothing about scanners and are shocked at hearing "donald duck" voices on their radio, i guess it serves it's purpose.

 

[IdleMonitor]

Passing through the area today, The Police dispatch talkgroup on the trunked system was in the clear.

Voice inversion encryption just came up tonight on the Cobourg VHF channel. I am assuming the 800 trunk is the same as well.

 

[Jammin_Jay]

Well that makes a lot of sense. Keep one in the clear, and the other voice inverted. Perhaps theres more in development with the Trunking System.

 

[Nolat]

Yes as of May 17 / 2007 Cobourg Services are still operating on the 800MHz band .. I live right in town .

 

[Nolat]

You are correct.

Should be a standard voice inversion carrier around 3.5 khz such as the others in Eastern Ontario. Is it straight voice inversion, or just select transmissions. Do you hear DTMF soundalike tones after the modulation for id purposes or a sqwauk at the beginning of the transmission when in the clear mode. Just curious how there set-up is. Still easy to decode and listen to. I'd be curious of the trunking transmission as well. Can any member in the Northumberland area verify this?

We do hear the tones etc.. Im right in town .Their transmitter site is still in place "on the water tower" off Ontario street in Cobourg. Police still share the 800 band with local services fire, works, marina etc which one can listen too .

 

[Jammin_Jay]

Thanks, that answered my question in regards to inversion. If u here the tones at the end of transmissions, they are ID tones, which represent a radio or unit# to identify which officer has keyed up. They are also at the end of the transmission when the radio is switch to provincial common, in the clear mode, it automatically does this, takes it out of inversion, with a squawk at the start of the transmission. The dispatch should have no tones, just whichever radio is keying up to the repeater. Seems like a few ontario towns are using the set-up. Brockville, SmithsFalls, Perth, Gananoque, and Cobourg, so far.