jDSDPlus n' AIRSPY SDR

[Chris0516]

I have a a 325p2. I upgraded the scanner from just Analog/P25. I activated the NXDN then activated DMR. Then I found out that the 325p2 doesn't have LCN Finder. I was told to get DSDPlus n' AIRSPY SDR, in order to find the LCNs' for DMR/NXDN systems.

According to these directions-


If you're using DSDPlus to visually monitor the system, you can try a trick developed by many people simultaneously back when trying to figure out the LCN layout on EDACS and LTR systems. . .

1. Park the DSDPlus monitor radio on the "rest" channel or "control" channel (whatever one is sending out channel assignment data, or a periodic beacon).

2. Program the site frequencies into an ordinary analog voice scanner.

3. While watching DSDPlus system activity on the computer screen, listen for which channel goes active on the analog scanner.

It may take a few passes to confirm a particular channel beyond reasonable doubt, but as you confirm each channel, lock it out on the analog scanner. Eventually you'll pin down the LCN layout.

This is easier to do on a weekend when there is activity, but not as much activity as you would see on a weekday. The preferred goal is one active voice channel at a time.

Finally. . .
Connect Plus systems can use a maximum of 15 repeaters per site. However, there is a maximum of 770 traffic slots, so for a 70-site system no more than 6 repeaters per site, and for a 250-site system no more than 2 repeaters per site).

Capacity Max (the new Motorola control-channel based system which uses the ETSI standard) can use a maximum of 250 sites with up to 15 channels per site. Limitations similar to Connect Plus probably apply.

Capacity Plus (single-site) and Linked Capacity Plus (multi-site) use a "rest" channel rather than a continuous control channel, maximum 1200 radios, up to 15 sites and up to 6 repeaters per site.

-----Why do I have to use my BC75XLT to get LCNs', instead of my BCD325p2? I am confused.

 

[lwvmobile]

That's the general method we've used in Florida to pin down LCN channels for the EDACS/SLERS system, but it really just works best if you already know which frequencies you should be testing ahead of time to nail down which frequency equals which LCN. Typically, you can use whatever scanner you want, I just put the suspected LCN frequencies in my analog scanner and let it scan while my SDR and software watch the output on the control channel for which LCN is currently active and just notate which frequency belongs to which LCN on a given system. Not to mention, like you said, anytime you want to figure something out, there is NEVER ANY TRAFFIC.

Not quite sure if its the exact method for other systems, but it should be good assuming that the LCN channels don't switch frequencies.

 

[sonm10]

Or to be simpler, just sit an any frequency and it will tell you the logical channel number (NXDN) or logical slot number (DMR).

Remember, for DMR, the LSN has to be converted to LCN for 325 to work. Divide by 2 and take the lower of (I think).