Encrypted traffic vs. simulcast distortion traffic - What do I hear?

[JohnDistai]

I'm listening to Viper Simulcast using a SDS 200 and a 996xt. Some traffic is garbled, but portions are semi-coherent. Not sure which radio these calls are on, as both get traffic hits at the same time.

How would I distinguish encrypted traffic from a simulcast distorted traffic? What would I hear (or not), that would help me determine the cause of the distorted traffic?

Also, on one of the Medical calls today, the automated voice read out the address. One of my radios played some mask sound over the street name. The other announced the street name. Any idea what happened?

 

[fredva]

Encrypted transmissions would not be semi-coherent, as in you wouldn't be able to pick out any words that are spoken. I'm not sure about the 996XT, but with the SDS-200, the radio should mute encrypted traffic.

Since the SDS-200 should receive simulcast transmissions well, I would suggest turning off the 996 and listen only to the SDS-200 as a test, to see if the transmissions are clear. If so, the 996 is struggling with simulcast.

Did you start listening to ViPR simulcast with both radios at the same time? Often one has a history with one scanner before getting another.

 

[eorange]

Simulcast distortion is very choppy speech with some occasional buzzing, but in general you know it's speech. Encryption is a blast of fast squeaky harsh tones all over the place.

 

[fxdscon]

a blast of fast squeaky harsh tones all over the place.

Just like when my wife is angry.

 

[JohnDistai]

The 996xt usually catches traffic before the SDS 200. There's generally a few seconds delay, especially on the same medical call.

 

[tvengr]

What is your city and county and which agencies are you monitoring?

 

[wtp]

not going out too far on a limb..if you hear anything it is not encrypted.

 

[Soundman]

When you are scan you should see a Enc on your scanner . That mean it is Encrypted .For simulcast distortion if you hear the dispatch say something and then you don't hear the rest of the call .That is simulcast distortion . I had to sell my bcd436hp because of the simulcast distortion in Charlotte .Now I have the sds100 and I can hear everything .

 

[iMONITOR]

Simulcast distortion sounds like a combination of Donald Duck and talking with a mouth full of water. If you have a Uniden scanner you won't hear anything if the signal is encrypted.

 

[hamstang]

I was monitoring Charlotte UASI for several years using a BCD996XT before up grading to an SDS200. After upgrading to the SDS200, I was amazed how much I had been missing with the 996XT due to simulcast issues even using an outdoor yagi antenna. The 996XT does work great for the 2 VIPER sites I monitor.

 

[chief21]

I'm listening to Viper Simulcast using a SDS 200 and a 996xt. Some traffic is garbled, but portions are semi-coherent.

Here in WNC, all of the VIPER sites that I can hear each use discrete frequencies - no simulcast at all. Are there some areas in NC where the VIPER sites are simulcast?

 

[Soundman]

Viper works great . I have a 536hp and a home patrol hooked to a yagi antenna and it works great . I have a sds100 and wow it is a great scanner for Charlotte .I did have a 436hp and I sold it for the sds100 . I have bc99xt I am trying to sell I just don't like it . I have a bc796d and it work good with the charlotte system . It odd but it works .

 

[JohnDistai]

What is your city and county and which agencies are you monitoring?

Raleigh, Wake County, NC. Trying to listen to EMS, LEO. I didn't listen for a long time during the protests, as it seemed that RPD went encrypted. I resumed yesterday. No RPD calls appearing that I'm aware of; perhaps I'm not checking the display when they do hit.

I'm not logging, as I'm running a Mac with a Parallels Windows 10 setup. ProScan seems to connect to the units after several tries. It becomes such a hassle I don't persist trying.

 

[JohnDistai]

Raleigh, Wake County, NC. Trying to listen to EMS, LEO. I didn't listen for a long time during the protests, as it seemed that RPD went encrypted. I resumed yesterday. No RPD calls appearing that I'm aware of; perhaps I'm not checking the display when they do hit.

I'm not logging, as I'm running a Mac with a Parallels Windows 10 setup. ProScan seems to connect to the units after several tries. It becomes such a hassle I don't persist trying.

Some of the calls seem to sound like someone talking with marbles in their mouth. A few words come out and then there's quick breaks in transmission before the radio resumes scanning. Is this simulcast distortion?

 

[Hit_Factor]

Some of the calls seem to sound like someone talking with marbles in their mouth. A few words come out and then there's quick breaks in transmission before the radio resumes scanning. Is this simulcast distortion?

Probably so, encryption would not be recognizable as voices.

 

[Whiskey3JMC]

Let's cut to the chase. All talkgroups here designated as mode "DE" are encrypted full time. It's a very large system and most talkgroups are mode "D" meaning they are in the clear. Hope this helps

 

[Whiskey3JMC]

If you have a Uniden scanner you won't hear anything if the signal is encrypted.

Partially true. While scanning, no audio will pass through. (in most cases) However once in a blue moon you'll hear a blip or two if you're held on the frequency (quick search on a 536hp for example). You'll hear even more segments of a transmission if it is simulcast but it will be somewhat intelligible, unlike encryption

 

[fredva]

Raleigh, Wake County, NC. Trying to listen to EMS, LEO. I didn't listen for a long time during the protests, as it seemed that RPD went encrypted. I resumed yesterday. No RPD calls appearing that I'm aware of; perhaps I'm not checking the display when they do hit.

Ok, you said in your first post that you were listening to ViPR. But now you mention Raleigh PD in Wake County. Raleigh PD is not on ViPR but rather the separate Wake County Simulcast system, according to the database. If that is what you are actually monitoring, then simulcast distortion is very possible.

ViPR has at least a couple of simulcast sites in the state (Gaston and Davidson), but it doesn't look like ViPR is simulcast in your county.