First, welcome to RR, best scanning and other listening site on the web.
Dead time is not all that uncommon. Especially for smaller areas. St. Louis should be much more active.
Taking a look at the
database for St. Louis county, the 246 will be able to scan nearly everything that is there. It does look like the city is going to a P25 (that is digital) system in the forseeable future. The 246 will not be able to pick that up when it happens.
The county itself is still showing conventional frequencies, so the 246 will be excellant for that.
As to whether or not you can mix trunked and conventional, the answer is yes you can. With the dynamic memory allocation of the 246, you can even set more than one trunked system up under the same quick key.
Now you cannot mix conventional and trunked information in the same system. That one may take some getting used to. As you work into the scanning world and begin to better understand the 246, that statement will become a bit clearer.
Software is the best way to program, so you started out smartly.
Also take time to look through the rest of the forums (there are close to 100 including one for each state and various types of radios). Learn to use the database. It is better now than ever.
Some systems that you cannot track with the 246 (or anyother scanner for that matter) include EDACS Provoice and LTR Multinet (system? forget the proper name as I don't have any near me). Provoice is a proprietary digital format and LTR in general is difficult to track, the Multinet cannot be.