dmr freq question

[dave3825]

How do you tell if dmr freqs is part of a system or if they are single stand alone freqs?

The following freqs are listed in the db but they are definitely dmr, cap plus to be exact. Islip (Town) Suffolk County, New York (NY) Scanner Frequencies and Radio Frequency Reference

Frequency License Type Tone Alpha Tag Description Mode Tag
470.91250 WIL716 RM 136.5 PL Islip OEM Office of Emergency Management FM Emergency Ops
471.33750 WEC745 RM 136.5 PL Islip Code 1 Code FM Multi-Dispatch
471.36250 WEC745 RM 136.5 PL Islip Code 2 Code FM Multi-Tac
470.36250 WEC745 RM 136.5 PL Islip Code 3 Code FM Multi-Tac
471.38750 WEC745 RM 136.5 PL Islip Code 4 Code FM Multi-Talk

Just curious since the detail info is what it is and the freqs are now dmr. How do you tell?

 

[natedawg1604]

Monitor each frequency individually with a single instance of DSD+, the event log & channel activity windows should display all the relevant system information pretty darn quickly.

 

[dave3825]

Monitor each frequency individually with a single instance of DSD+, the event log & channel activity windows should display all the relevant system information pretty darn quickly.

What exactly am I looking for? Ch1 ch2 ch3 etc? That would be a system as opposed to slot 1 and slot 2?

 

[natedawg1604]

What exactly am I looking for? Ch1 ch2 ch3 etc? That would be a system as opposed to slot 1 and slot 2?

Honestly I wouldn't even worry about it, first you just need to get DSD+ up and running along with a rtl sdr source program such as FMP or SDR# (assuming you have an RTL SDR dongle or a tapped scanner, one of which will be needed to get started).

If you have a Cap+ or Con+ system (DSD+ will also tell you this automatically), you need to determine which OTA channel pairs (1/2, 3/4, 5/6, 7/8 etc) are associated with a specific frequency. In the newer Fastlane versions it displays an explicit message as soon as a channel pair is detected. But with DSD+ 1.101 (latest free version) you can still easily figure it out, just wait to hear voice grants and then see which OTA channel is displayed when you hear voice traffic.

 

[slicerwizard]

How do you tell if dmr freqs is part of a system or if they are single stand alone freqs?

Just keep track of what talkgroups and radio IDs show up on each frequency. If there is a correlation, like calls jumping from one frequency to another, the frequencies are part of the same system (site) or network. You can speed up the process by monitoring multiple channels. You could set up FMP with a scanlist to cycle through all of the channels - that way, you automatically catch most of the calls. Per-call audio files can be useful as well. And as noted, the FL versions help by determining Cap+ repeater numbers and by adding frequency information to the event log entries, which lets you set up unattended monitoring - overnight, all day, whatever - and then analyze the logged data: which frequencies does each talkgroup show up on? do group calls ever move from one frequency to another? stuff like that...