NJSP 800 Trunk System vs NJICS 700 system Part 2

So you have both systems programmed into your scanner, sometimes you hear things on 1 system, but not the other.  What is going on?

Most of it has to do with radio affiliations.  A good example of this are the NJSP radio's.  Most are 800 only, but the newer APX 700 radio's are slowing being introduced.  Not only NJSP,  but other agencies as well.  As I said in Part 1, the 700 sites are smaller, so if you live near the coast, you may hear the NJSP Marine police on 700, but those of us on the North West part of the state may never see that show up.

There is a 700 talkgroup equivalent for every 800 talkgroup.  On the 700 side, if you are trying to identify a 700 talkgroup, multiply it by 16, and chances are it will be an existing talkgroup on the 800 side.  If the 700 talkgroup is larger than 4096, then it would be a 700 only talkgroup (The 800 system will only go up to 65536).   Same thing goes for radio ID's, anything you see 66000 or higher will be a 700 only ID.   Any of the upper ID's will show up on the 800 side as 65520.

Real world example
Lets say we have 3 users all on StateCom 2.  User 1 has an 800 radio and is in Morristown.  User 2 has a 700 radio and is in Cape May with a Cape May Co radio (Woodbine Site) and User 3 has a 700 radio and is in Camden with a Camden Co Radio(Berlin Site).  No one else has affiliated with this talkgroup.

In this scenario, what you will wind up with is this:
StateCom 2 will come across the entire Troop B System, the Woodbine site and Berlin site.  No one anywhere else will hear it.  In addition, the 2 South Jersey sites will see all the radio ID's correctly, since they are both 700, however on the North Jersey 800 side, you will see the right radio ID for the guy in Morristown since it is an 800 radio, but for the 2 700 radios in South Jersey, both will show up as 65520.

Not everything can go everywhere, or sometimes they just don't
Not every talkgroup on the 700 can go everywhere in the state.  Union County talkgroups appear to be restricted to the Union and West Orange sites (maybe others).  They do not carry over to the Hunterdon Site, even though Union County radio's frequently show up in Unitrunker.   Another recent development is the new Rutgers 700 site, soon as that went live, the Rutgers activity on the Hunterdon site pretty much stopped.  

Another thing to bear in mind is that most, if not all the radios programmed on the 700 have all the StateCom talkgroups, so it is very possible to hear some units that you do not normally hear on them.  This is why it is important to program the radio ID's in your scanner if it is capable.  If someone shows up on one of these channels, you can easily identify who it is.

One Final Thought
There has been discussion on the NJ Transit radio's recently.  Often you hear activity on 800, 700, sometimes both, sometimes it bounces from 1 to the other.  They may be a few reasons for this.  1 is different radio's affiliated at different locations, plus these guys outside the North East are always on the move, so sites change often.  The other possible explanation for this may be that some of these guys keep their radios on scan, so they may be bouncing between the 700 & 800 talkgroups, depending on the radio.