LASD Gang Units normally monitor their home channel or the dispatch channel for the area they are working on any given day. You can usually identify them by their call sign as the general rule is they use the first number of their stations call sign designator or "series" which (like all stations callsigns) is derived from the station number;
For Example, Lancaster is station # 11 - And their designated callsigns are the "110 - 119" series - A gang unit working Lancaster would more than likely have a "110G, 110G1, 110G2, etc" callsign.
East LA is station #2 and their callsigns fall into the 20-29 series, so an East LA Gang Car would more than likely use a "20G, G1 G2" series as their callsign.
South LA (Lennox) is station #3 and they use 30-35 series so 30G, G1 etc...
Temple is #5 and uses 50-59, Santa Clarita #6, so they use 60-69 .. Norwalk is # 4 so they use 40 - 49 series, and on down the line, you get the idea;
There is a fair amount of radio traffic from the gang units on the home dispatch channel, as they will run a lot of subjects over the air via SCC to check for wants and warrants, especially when running a subject with a very common name as the dispatcher at SCC can ascertain quicker if the subject has warrants, as a common name can produce up to 30+ pages of returns or "hits" on a subject and this ultimately clogs up a field units MDT if they run a common name from their car's MDT, and in some cases they might have to use SCC if they are in a U/C car not equipped with an MDT.
However, more often than not, most specialized cars working a target area will probably be on a tactical simplex channel that they reserve via SCC for an operation, so this might be why you're not hearing too much chatter, especially if they are using a "Star Tac" channel in simplex mode. Unless you're close to them, you won't hear much since they aren't utilizing a repeater;
Just to clarify, not all callsigns with a "G" or "George" designator are gang cars; You will hear other "George" units out and about, but the general rule is if it's a stations first "series" number with a G in it, then that would be a gang car. Special Countywide units that conduct saturation patrols/operations in each city or region for, say a week at a time will use a "Nora" callsign with the stations first designated numbers, IE: Lancaster 110N4, East LA 20N2, Norwalk 40N1, etc, and a Sergeant would use a "Nora Sam" callsign that corresponds to the respected station area/city they are working in on that given day/week.
Then there are the OSS Units out and about countywide and they are numbered by the area they work - An OSSG60 series unit would be a north county Lancaster/Palmdale car, but this isn't set in stone as they sometimes work different regions, yet keep the same callsign - You will probably hear more traffic from an OSS unit on the home dispatch channel and L-Tac more often than on an area tactical, Star tac or Mutual Aid frequency.
Something else to consider if you aren't hearing much traffic on the primary channels is that almost any "working" channel can be used in simplex mode - Thus allowing units to operate in close range, in simplex mode on any channel of their liking, a convenient tool if all of the "official" tactical channels are in use - The only hitch being they would have to use a channel that is out of the area so as to not interfere with the home channels units; So say East LA units need a simplex channel for an operation, they could simply switch their radios to Lancaster's L-Tac and communicate via simplex with one another - They are too far away to interfere with any Lancaster units using L-Tac and also too far away to pick up L-tac traffic from Lancaster, so now they have a clear channel to use. It's not uncommon to occasionally hear local simplex traffic on another stations L-Tac or home channel - It's just a matter of timing and antenna. If you have a good antenna setup you can usually hear most radio traffic on the input frequency of a dispatch channel - Always a plus and interesting to hear what the field units are saying to SCC, since all you will hear on the output frequency is the busy tone or "annoying beeps" as they are commonly referred as. Just program as many LASD freqs as you can and that should do the trick. Hope this info helped answer your question. Good luck!
