long islands Ltr mixed county system??

[tommyscan]

Here in long isalnd there are a few easily heard Ltr systems used by bus/ambulance and taxi-delivery services. Many are mixed county!! How does one know what frequency belongs to what system?? I am trying to catch,log and post the nassau norcom system. Suffolk norcom,our adjoining county was much easier to configure the Lcn order cause it did not share frequencies. Any help would be appreciated. I am just using the radios feature of putting the home repeatres in order. No software or other equipment.

[captclint]

Originally Posted by tommyscan

Here in long island there are a few easily heard Ltr systems used by bus/ambulance and taxi-delivery services. Many are mixed county!! How does one know what frequency belongs to what system??

Have the same problem, which is compounded by the use of one or two frequencies from a different FCC license, and location, in other systems/FCC but same FRN licensee. I use signal strength, and type of conversations. If you keep good notes about names and places heard with each TGID, you can often tell that the TGID's that don't fit with a particular system. Also, you will find that the same users can have different TGID's when roaming on different systems if the same FRN licensee is involved in more than 1 system.

The key to verification is making sure that the LCN's do switch properly when channels are busy. For example, I have two LCN05 frequencies. When I insert one into a system, if the 05 users don't switch to another LCN in the system with voice, I know I have the wrong LCN05. Doesn't have to be proper LCN05 switching. If a verified LCN02 tries to switch to LCN05, and there is no voice, you also know it is wrong.
This is very painful and challenging, but I don't know of a better way without using the discriminator tap...which I have resisted so far.