ENC displayed when no encryption -- decoding error?

[wolter]

I have seen ENC display in a 396 several times on a P25 channel that I know does not use encryption. It will display for a split second, then disappear during a transmission. Is this a decoding error by the 396?

 

[DaveIN]

Is this on a 9600 baud P25 system or 3600 baud mixed mode system?

 

[sgfitzs]

I've seen the same thing while listening to the Maryland state police. If the P25 signal is weak, ENC wil display briefly and the audio will be poor. As soon as the signal strength increases a bit, the ENC disappears and the audio clears up.

 

[wolter]

Is this on a 9600 baud P25 system or 3600 baud mixed mode system?

I've seen this with 3600 and conventional systems.

If the P25 signal is weak, ENC wil display briefly and the audio will be poor.

How weak is too weak? I've seen this with 3 and 4 bars; I've never bothered to look when receiving 5 bars.

 

[SCPD]

I see it all the time usually at the start of the transmission. Does not seem to have any impact on the tx though. Don't know if this is design or error though.

 

[DaveIN]

I'm thinking it may bethat the 996 sees "some" link data as encrypted for the 3600 baud system, but the conventional I don't know, as I've not used it on conventional P25.

 

[poltergeisty]

I'm thinking it's a crapy vocoder/D to A convertor in the radio. :lol:

 

[jparks29]

I've seen the same thing while listening to the Maryland state police. If the P25 signal is weak, ENC wil display briefly and the audio will be poor. As soon as the signal strength increases a bit, the ENC disappears and the audio clears up.

where is Maryland State Police using P25??? Other than a patch on a county system?

 

[wolter]

Does not seem to have any impact on the tx though.

I've noticed it muting the audio, as its designed to do with encrypted traffic; the beginning of the transmission is chopped off. But this isn't encrypted traffic, so it is annoying even though it is just for a short moment.

I'm thinking it may bethat the 996 sees "some" link data as encrypted.

I'm seeing it on the 396. If you're seeing it on the 996 too, it may be a Uniden thing. I'd be curious to know if GRE/Rat Shack people report decoding errors also.

 

[poltergeisty]

Any of you have a MOTO to compare this anomaly with?

It would certainly verify my theory. He he :lol:

 

[SCPD]

Took another look at the users manual. It says:
ENC- appears when APCO P25 encrypted data is being received on a voice channel.

After paying closer attention today, this would seem to be the case on the system I'm monitoring. There's a short burst of -- for lack of a better term-- static before the beginning of the transmission. I'm not finding that this is causing anything to get chopped. It is a brief burst of 1/2 sec or less. So it would seem to be design. Doesn't seem to matter on mine what the signal is...2 bar or 5 bar same thing happens.
This experience is with Ontario's Fleetnet system monitoring the OPP.

 

[poltergeisty]

I forget what they call that with the burst of digital before the radio TX, but it's common with the radio systems in digital format. I hear that only when I am searching the 800 MHz band and someone comes on, but not when the talk groups programed.

It could very well be that because it carrys no voice.