I'm new to DSD+ and am using it mostly to research new systems. I find it difficult to identify the LCN (LSNs) of the frequency I am decoding on Cap+ systems. Only the Channel Activity window seems to provide useful information in this regard, which itself is frustrating because it changes rapidly and doesn't record anything. At first I thought that the first LSNs to show up in the Channel Activity window when I start DSD+ applied to the monitored frequency, but this is not consistent. Is there a simple way to identify the LCN/LSNs of the frequency I'm monitoring?
A secondary puzzle not directly related to DSD+: I'm monitoring two nearby frequencies with DSD+ that are clearly related as the two frequencies of a Cap+ system (same TGs active at the same time, active GPS reports on the same mobiles, etc.). DSD+ shows 4 LSNs (1-4) while sitting on either frequency. But one frequency consistently shows Site 5 and Color Code 5, and the other consistently shows Site 1 and Color Code 11! I have carefully scanned the whole band, and there is nothing else related to this system. Has anyone seen a case like this? What am I to think??
So you have two separate sites (1 and 5), each with 4 LSNs (two LCNs -- two frequencies), and they are related (same talkgroup activity at the same times). Makes sense for a multisite Cap+ system.
Obviously, the two frequencies you have been listening to (one from each site). Although likely that two-channel Cap+ sites will have LCN 1 and LCN 2, they could be LCN 5 and LCN 9 for example, if that is how the sysadmin configured them.
Time to look up FCC data and find other frequencies associated with those site locations. You didn't mention anything about what FCC licenses you believe are associated with these sites, and that would be helpful in instructing you where to look next.
If you sit on any Cap+ freq long enough for a voice transmission to occur, at that time you will see a notification in the main DSDPlus window that specifically tells you which LCN it is. Without voice activity though, determining LCNs becomes much harder. So you want to monitor these systems during their peak days/hours. If you do that, and if you know for sure the agency and cross reference it to FCC licenses, it should be fairly simple to determine the other frequency associated with each of those two sites. Once you know freqs/lcns for a site and you populate DSDPlus.Networks, DSDPlus.Sites and DSDPlus.Frequencies , you should have no trouble tracking each site.
As is the case with all Cap+ sites, since they do not broadcast a System/Network ID, you have to make one up of your own to add them to the appropriate DSDPlus.* files. Or, if the system is known and is in the DB, you can use RR's SID as the system ID.
Example: local to me - First Energy Sammis Plant -
First Energy - Sammis Plant Trunking System, Stratton, Ohio - Scanner Frequencies
Note that the ?sid=10126 in the RRDB. This has NOTHING to do with the actual trunked system configuration. But it is useful to use the sid as the fake network/system ID when adding the system, site and frequencies to the DSDPlus.* files.
In my example, the fake system/network ID is going to be 10126
DSDPlus.Networks
; line format: protocol, networkID, "network name"[, TIIIareaLength]
Cap+,10126,"First Energy Sammis"
DSDPlus.Sites
; line format: protocol, networkID, siteNumber, "site name"
Cap+,10126,2,"Hilltop"
DSDPlus.frequencies
; protocol, networkID, siteNumber, OTAchannelNumber, TXfrequency, RXfrequency, sortOrder
Cap+,10126,2,1,451.275,456.275,1 ; LCN 1
Cap+,10126,2,2,451.275,456.275,2 ; LCN 1
Cap+,10126,2,3,452.075,457.075,3 ; LCN 2
Cap+,10126,2,4,452.075,457.075,4 ; LCN 2
Cap+,10126,2,5,451.200,456.200,5 ; LCN 3
Cap+,10126,2,6,451.200,456.200,6 ; LCN 3
Notice that in the DSDPlus.frequencies file the OTAchannelNumber is the LSN (not the LCN). And you don't have to include each LSN, but you need to include one for each LCN/freq. You could just do:
Cap+,10126,2,1,451.275,456.275,1 ; LCN 1
Cap+,10126,2,3,452.075,457.075,3 ; LCN 2
Cap+,10126,2,5,451.200,456.200,5 ; LCN 3
Mike
