Difficulty Scanning Federal Prison 3600 TRS

[vinzep491]

Hello, I posted an earlier thread in the Sout hCarolina forums and was looking to see if anyone on this side of the site could help me out. I'm not trying to double post, so if this will get me in trouble feel free to delete it mods. I'm just trying to direct people who may have my answer to the thread.

Anyways, I'm having a hard time tracking a Fed Prison TRS. It has a CC and at least 3 other freqs in the 407-410 range. I have tuned in to the voice freqs manually and heard p25 voice but can not get the system to trunk properly with just the CC entered into my Pro197, as well as failing to work when I enter all system freqs that I have discovered thus far.

Thee CC in tune mode on the 197 is reading M36 and comes in loud and clear, but the reciever will not monitor the system with any of the TRS modes, including Moto UHF/VHF, p25 manual, and p25 auto.

If anyone has any idea that can help me concure this mystery federal trs, please check out my original thread, which probaly should have been here in this section in the first place... Thanks everyone.
http://forums.radioreference.com/south-carolina-radio-discussion-forum/238568-fci-bennettsville.html
Mod please lock.

 

[mmtstc]

I have also had this problem on the federal BOP systems. their systems rotate control channels at midnight every day and with each control channel, comes a unique base offset and even with that, it is still not ideal listening.

The way that I have found works best for me, and only because I have the luxury of having bought plenty of toys BEFORE I got married, is that I take my 396t and program in the voice frequencies and just set it to scan. I then take my 396xt and tune to the control channel and open up UniTrunker and let it rip. This way I can hear the voice traffic, and make a very informed decision as to that talkgroup is being used.

Of the 10 or so BOP systems I have monitored, 2 have been easy to monitor and one of them was conventional VHF project 25.

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[ChrisP]

Anyways, I'm having a hard time tracking a Fed Prison TRS. It has a CC and at least 3 other freqs in the 407-410 range. I have tuned in to the voice freqs manually and heard p25 voice but can not get the system to trunk properly with just the CC entered into my Pro197, as well as failing to work when I enter all system freqs that I have discovered thus far.

These systems will not trunk track with just the control channels entered. You will need to add a table of base, offset & step frequencies for these Motorola Type II systems to trunk track. The voice is P-25 digital, but the control channel is not, and is not broadcasting these tables to the scanner, as a true P-25 system would do.

As far as figuring out these table settings, check the database info here in Radio Reference and see if they are already listed. If not, you will probably have to analyze the system control channel with a software package such as Trunker or Unitrunker to figure out what you need.

- Chris

 

[WayneH]

I have also had this problem on the federal BOP systems. their systems rotate control channels at midnight every day and with each control channel, comes a unique base offset and even with that, it is still not ideal listening.

This sounds like none of your calculations for base and spacing were right.

I've seen some off the wall setups for BOP but they're typically single ranges/bases. If the freqs are very far apart then there's a possibility there are multiple bases but for 406-420 operation it's not really needed. Sometimes the staging facility likes to get creative though.


To the OP, the 197 has an advanced option that when turned on will display the hex code for the control channel. Using that with the proper calculations can give you somewhere to start. There are countless threads on here going over doing the math.