OK Don-- very good--- since you program them as "Private" TGRP objects, you will only be alerted when they transmit in private mode-- is that correct? If they transmit in "Group" mode, you will not be alerted. I hope I am reading this right.
If you program a "Private" TGRP object with a specific RadioID, you'll get that object's "Alert" when:
1. that RadioID is involved in a private (Radio -> Radio) call
2. that RadioID initiates a group (talkgroup ID -based) call, IF AND ONLY IF you have the "RadioIDAlert" option set to "Yes" AND the scanner is able to detect that RadioID from the control channel messages.
For example, my local system rarely (if ever) uses private calls. I do have some RadioIDs programmed into "Private" TGRP objects, though. I have the "RadioIDAlert" option set to "Yes". My local system is not very busy. For about 45% of the "group" calls, I do get the RadioID alerts - these are "talkgroup ID" calls initiated by the dispatch consoles, fire apparatus, etc. that I have programmed as "Private" TGRP objects.
Here's how "group calls" work in the scanner:
1. Monitoring CC
2. Get "call grant" or "call update" message
3. TGID in message matches not-locked-out programmed TGID? If no, back to #1
4. If the message does NOT contain a radio ID (e.g. an "update" message), just show the "group" TGRP info
5. Do we have a "private" TGRP object for this RadioID? If no, just show the numeric RadioID on line 4.
6. "RadioIDAlert" enabled? If no, just show the "private" TGRP object's alpha tag
7. Any alert settings (LED, Audio) for this "private" TGRP? If no, use any alert settings for the TGID's TGRP object
8. Show/sound any alert settings for the "private" TGRP object.
If my scanner sees a "call grant" message on the "Police Dispatch" talkgroup, and the call was initiated by one of the dispatch consoles, I get an alert specific to that console, since I have them programmed as "private" TGRP objects. If, however, some random officer calls from his vehicle radio on the Police Dispatch talkgroup, I'll just see the vehicle's RadioID on line 4 - since I don't have the vehicles programmed as private TGRP objects.