I came across this frequency during a search and it showed alot of CAP+ activity with a strong signal and a CC of 9 switching between slot 1 and 2. I did not find it in the RRdb but I may have missed it. Anyway, I wanted to dig further so created a new MotoTRBO system with the frequency and color code and then ran LCN finder twice each for 2 days and no results came up. During the LCN sessions, there was alot of activity. Has anyone been able to program this system successfully and/or am I missing? I really appreciate any feedback. (I am using an SDS100.)
Houston 452.9875 - Cap+ System
- Thread starter mktee76
- Start date
Where in Houston did you pick it up?
LCN finder won’t find new frequencies, it will find the LCN of frequencies you have programmed in. Also be aware it won’t capture the LCN of a Cap+ rest channel until it’s no longer a rest channel and is used purely as a voice channel.
Cap+ are an unusual creature in comparison to a regular trunked system. Here's an overview of how it works:
Each radio is loaded with all frequencies and time slot assignments (there are 2 time slots per 12.5k frequency).
There is no control channel like a typical trunked system that the radio monitors, so there's very little over the air updates between the radios and the repeater (for example a radio will not announce a talkgroup affiliation, and a multi-site system will broadcast all traffic on repeaters on each site).
One time slot will broadcast a "rest" beacon (it pulses and is not continuous), which all radios will search for. Once found, the radios will monitor that beacon for instructions.
When a user keys up (for example on Talkgroup 1), the rest beacon will tell all radios "unless you are monitoring Talkgroup 1, go monitor this new time slot) - the voice traffic for that talkgroup then replaces the "rest" beacon, and the beacon itself will move to the timeslot it instructed all other radios to go to.
Depending on the configuration of the system, the rest beacon may rotate round-robin amongst all the time slots on all the frequencies, a portion of the frequencies, or default to a "home" frequency when idle.
If the feature is enabled, some Cap+ systems will have a second beacon that is used for LRRP "location" (GPS coordinates, direction of travel and speed).
So, getting back to @KevinC's point, if the system has no activity, LCN finder does not work (LCN finder works based on matching activity on a known frequency with the messages from the rest channel). Also, LCN finder is dependent on activity being on all frequencies at some point, otherwise it will never finish. Likewise, if you fall upon the LRRP beacon, the scanner might show a Cap+ system, but you'll never see any traffic, and thus LCN finder will not work, unless the rest channel mysteriously finds it onto the same frequency (but the other timeslot) as the LRRP data.
Because of the intermittent nature of the beacons, a band search on the SDS's might miss the beacon (but once it locks on, it will hold on it). Also, because the Cap+ system doesn't broadcast a unique system ID, you don't have that to fall back on either. The new waterfall addon for the SDS's, or an SDR radio and a laptop (I use the paid "fast lane" version of a software program called DSDPlus on my mobile setup) is your best friend for finding those beacons and their strength, since sometimes a distance signal may throw you off, and it takes getting close to the source (and thus a very strong signal) to confirm where it's from. Likewise, the Software on a laptop can decode the LRRP broadcasts to make sure that's not what's throwing your scanner off.
Nope, not falling for it.
wtp
Member
mktee, i sent a PM with some possible users with that freq.
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