SDS100/SDS200: police scanner and technical functionality

[GROL]

what exactly i am planning to do it is to program on my sds100 in a way to mimic the beartracker warning system of 885 model or Target BluEYE. just reporting transmissions just from LE talkgroups nearby. I think This should be totally possible with P25 systems since the uniden system is able to pick P25 Phase 1 and 2. I even do not care about that talks go full encrypted but i also need to configurate a beep sound alert when they appear

Not going to work the way you describe. Traffic of individual units you may have programmed an LE talkgroup for, will be coming from a repeater site, not the local unit. If you program in all the repeater inputs coming from the mobile units and attempt to monitor those, there are two issues. You will not be able to tell if they are even law enforcement or just the trash pickup or social services or anything else on the same system until you listen a while, and a conversation between two units will not stay on the same frequency. You can program unit IDs that are used by LE, but you are going to have to meticulously monitor to discover all of them and they can change whenever a units radio is replaced for repair. That would be every single mobile and hand held unit. And whatever you monitor you will not be able to tell if they are nearby let alone from what direction. Even trying this with a conventional system let alone a trunked system is highly unreliable. Even the idea of the Beartracker units was a joke and more marketing than useful. Also LE units are not constantly talking on the radio. You could happen upon units that have not transmitted for several minutes or an hour. Recently I was monitoring the Highway Patrol on a Friday night when it is often busy with drunk drivers and high speed chases other than the usual accidents. I realized I hadn't heard anything for about 2 hours. I thought something was wrong with my radio but it was fine. Troopers were just lucky to have a slow night.

 

[nessnet]

what exactly i am planning to do it is to program on my sds100 in a way to mimic the beartracker warning system of 885 model or Target BluEYE. just reporting transmissions just from LE talkgroups nearby. I think This should be totally possible with P25 systems since the uniden system is able to pick P25 Phase 1 and 2. I even do not care about that talks go full encrypted but i also need to configurate a beep sound alert when they appear

Why not look in the direction of a couple of RTL-SDRs and do everything via software?

 

[DeaconHarry16]

I was intrigued by this thread, so I looked up "the BearTracker Warning System."
This explanation came from the Uniden wiki for the 885 and makes the OP's request a bit more clear to me.

The BearTracker Warning System (BWS) alerts you to nearby public safety radio activity. This can give you an advanced warning of police activity and other hazards when you are driving.

The earliest BWS implementations primarily monitored for the frequencies used by mobile radio extenders -- radio units installed in patrol cars that extended the range of the officer's handheld radio. BWS has been extended to now include the "input" frequencies used by public safety agencies in each state. These frequencies are typically only receivable when you are up to 2 miles from the unit transmitting.

Because the frequencies used vary from location to location, we've set up the scanner so that all you need to do is select what state you are in. From that point, BWS will use frequencies most often used in your state to alert you to nearby activity.

That being said the 885 uses a database of input frequencies and scans these frequencies as a priority and sounds an alarm if one of the "close by" frequencies becomes active. All you hear is a sound or a panel indication of a hit...no audio. This function requires a specialized database of frequencies of interest, which I am sure would require periodic updates.

I suppose you could configure a favorites list for an SDS if you knew the frequencies of interest for a particular location and program a beep or light to indicate a hit.... BUT I can only imagine the trouble it would be to obtain and manually enter the data.... Whew

Good Luck
Harry

 

[GROL]

I was intrigued by this thread, so I looked up "the BearTracker Warning System."
This explanation came from the Uniden wiki for the 885 and makes the OP's request a bit more clear to me.

The BearTracker Warning System (BWS) alerts you to nearby public safety radio activity. This can give you an advanced warning of police activity and other hazards when you are driving.

The earliest BWS implementations primarily monitored for the frequencies used by mobile radio extenders -- radio units installed in patrol cars that extended the range of the officer's handheld radio. BWS has been extended to now include the "input" frequencies used by public safety agencies in each state. These frequencies are typically only receivable when you are up to 2 miles from the unit transmitting.

Because the frequencies used vary from location to location, we've set up the scanner so that all you need to do is select what state you are in. From that point, BWS will use frequencies most often used in your state to alert you to nearby activity.

That being said the 885 uses a database of input frequencies and scans these frequencies as a priority and sounds an alarm if one of the "close by" frequencies becomes active. All you hear is a sound or a panel indication of a hit...no audio. This function requires a specialized database of frequencies of interest, which I am sure would require periodic updates.

I suppose you could configure a favorites list for an SDS if you knew the frequencies of interest for a particular location and program a beep or light to indicate a hit.... BUT I can only imagine the trouble it would be to obtain and manually enter the data.... Whew

Good Luck
Harry

That all sounds good, but in practice not very effective. No way to tell how close they are or in which direction. And they don't transmit continuously. It's not as though they are constantly transmitting a signal and you have a direction finding antenna array on your roof. With monitoring trunked system repeater inputs no way to identify law enforcement units vs. everything else using the system. What if you are near a chatty city or county utility crew. Until you find out all the radio IDs of the LEO mobile and handhelds to scan for, you cannot know who is talking and still cannot depend on them transmitting to alert you and then know how far away and which direction. On a city, county or state trunked system frequencies are not assigned to just law enforcement. All departments use all the frequencies assigned by the system controller for an active transmission. And a conversation between units does not necessarily stay on the same frequency during the entire exchange. If you were attempting to avoid speeding tickets you would be putting on the brakes when you didn't need to and not braking when you need to. The whole idea is a futile effort.

If someone wants to attempt it, have at it. There will be great disappointment.

 

[dave3825]

While the concept totally makes sense, I don't see it happening with trunked systems. As @GROL said,

If you program in all the repeater inputs coming from the mobile units and attempt to monitor those, there are two issues. You will not be able to tell if they are even law enforcement or just the trash pickup or social services or anything else on the same system until you listen a while, and a conversation between two units will not stay on the same frequency.

Maybe with conventional freqs that use repeaters and those inputs tied to a location based database. In any event, I don't really see it functioning 100%

 

[OPTreadstone]

Why not look in the direction of a couple of RTL-SDRs and do everything via software?

Yes, I was thinking the same but i am absolute unexperienced about telecom so it would take me several weeks understanding and developing such project but if there is not anything that i can do with the sds100 i will take the SDR way

 

[mmckenna]

The earliest BWS implementations primarily monitored for the frequencies used by mobile radio extenders -- radio units installed in patrol cars that extended the range of the officer's handheld radio. BWS has been extended to now include the "input" frequencies used by public safety agencies in each state. These frequencies are typically only receivable when you are up to 2 miles from the unit transmitting.

It worked well, and you could do it with any scanner. I did it with my VHF "back in the day".

California Highway Patrol used VHF Low for everything back then. VHF low portable were not a reliable option. The solution was to use a VHF simplex frequency with a mobile extender. The mobile extender would interface to the higher power low band radio and provide a connection to the VHF hand held the officer carried.
In California, that was done on 154.905MHz. The mobile repeaters were only a few watts, so you knew if you heard radio traffic on there, you were close. The mobile repeaters could be shut off when not needed, so it wasn't always a good solution.

They switched to 700MHz for their mobile repeaters many years back. Others did to. Different areas used different frequencies, so it was no longer as easy as it used to be.

With better radio systems, the hand held/portable radio coverage improved, and the need for mobile repeaters disappeared in some areas, so again, not a solution for everyone any more. Some do still use mobile repeaters.

I still think this is going to be very difficult to do reliably. There are a lot of variables involved, and it won't be a slam dunk solution that fits every situation.

 

[Randyk4661]

I'm doing some bench testing here,
Using a 996P2 (mutes encrypted) listing to the local site inputs my PD uses and on a 796D (does not mute encrypted) side by side.
This is a phase 1 system and have not heard anything yet on either. Phase 2 system? Highly unlikely anything will work(?), more testing would be needed.

 

[GROL]

It worked well, and you could do it with any scanner. I did it with my VHF "back in the day".

California Highway Patrol used VHF Low for everything back then. VHF low portable were not a reliable option. The solution was to use a VHF simplex frequency with a mobile extender. The mobile extender would interface to the higher power low band radio and provide a connection to the VHF hand held the officer carried.
In California, that was done on 154.905MHz. The mobile repeaters were only a few watts, so you knew if you heard radio traffic on there, you were close. The mobile repeaters could be shut off when not needed, so it wasn't always a good solution.

They switched to 700MHz for their mobile repeaters many years back. Others did to. Different areas used different frequencies, so it was no longer as easy as it used to be.

With better radio systems, the hand held/portable radio coverage improved, and the need for mobile repeaters disappeared in some areas, so again, not a solution for everyone any more. Some do still use mobile repeaters.

I still think this is going to be very difficult to do reliably. There are a lot of variables involved, and it won't be a slam dunk solution that fits every situation.

North Carolina Highway Patrol was on Low Band until Viper trunked system and also had mobile repeaters. I think they were 154.415 Mhz. Problem is they did not have the mobile repeater active until they took the handheld out of the cradle. So it was not reliable for detecting their presence, and it didn't mean they were within your path of travel when it was active.

NCSHP was also on some of the same 42Mhz frequencies as CHP, and it was interesting to hear their traffic when conditions were right. My dad retired from NCSHP and told me about a time back in the 1960's when he and a CHP Trooper talked on the same simplex car to car frequency for a few mimutrs until it faded away.

 

[KN4EKW]

I nominate @MTS2000des.

Sure @MTS2000des is welcome to take a demonstration ride. Members of the radardetectorforum.org are using the Police Detector all over the country from FL,GA,TN,AL,SC,VA,PA,MD,WA,AZ So far. Greetings from KN4EKW - THE POLICE DETECTOR.

 

[AK9R]

This thread is no longer dealing with a Uniden Tech Support issue and the OP hasn't visited the forums for over a month. Thread locked.