How scanners trunk track
So, tell me if I'm doing more harm (to my listening pleasure) than good;
I've got an RS Pro-162 (20 banks) and have the county system spread through 3 banks and the city system in two banks.
I'd have to look at how that scanner works, as it is made by Uniden and not GRE. But I am fairly certain they work the same way and you are missing stuff.
County is bank 0 Sac Metro, bank 3 is LE south of the river, bank 4 is LE north of the river and banks 1-2 split Sac FD/PD. I almost never listen to Metro Fire and SSD at the same time, and I am rarely interested in events in Elk Grove or RC, so I split them up.
Well, if you only have the same control channel turned on ONCE, then it is not a problem. You miss calls when the same control channel is activated in more than one bank at the same time. Let me explain ....
I don't quite understand what you have in what banks, but I'll give an example that I think is close. Let's say you have County in bank 0 ON and Sac LE ON in bank 4 at the same time. They are using the same control channel, but each bank has a different selection of TG IDs.
The scanner is in bank 0, it detects a TG ID from CHPD. That TG is not in bank 0 so the call is ignored. Eventually the scanner gets to bank 4. The data for the prior call is long gone, now it detects a TG ID for SSD 1. That TG is not in bank 4 so the call is ignored.
The thing about TG ID transmissions is that they are not continuous. Some do repeat, but many do not. I've found that fire dispatch calls are repeated the most, but general LE traffic is not. You can test this condition easily. Turn on ONE bank in your scanner (in theory only one channel is on, the channel with the active control channel). Press SCAN and wait for a call. When the call starts to talk (the scanner is on the voice channel) press SCAN. Does the scanner immediately return to the same call? It would if it were a conventional channel, but usually does not if it is a trunked channel.
Should I keep the county system in one bank (fire and LE) and the city in another? Does it make much difference?
Put the city sites in one bank and the county sites in another bank. My (GRE) scanners use sub-groups to help manage TGs. That is how a user is supposed to select what they want to hear on a TRS, not via banks. I have Sac PD in one sub-group because I don't monitor them 24/7. I have 2 sub-groups of fire, 1 sub-group for Sac Sheriff and 1 sub-group for other LE. Additionally individual TGs can be locked out.
My newer scanners can hold 150 TGs per bank. If you want to listen to more than 150 TGs, perhaps you should be in ID search mode (open on GRE scanners). The newer scanners (like the PSR-300) also let you run an open bank and list TGs to ignore, another way to get past the 150 TG limit.
While these things can be programmed in many different ways, there is really only one best way which facilitates how you want to monitor. Unfortunately that best way does not always make it easy to turn stuff on and off. Another reason to run multiple scanners.