Probably not. You'll need something a bit more broadbanded - that antenna is fine for public service work, though. I seem to recall that ComTelco or Scanner Master had advertised on RR a mag mount antenna that covered 25-1300 mhz. Now I know it's not going to cover all bands equally - no antenna, not even a discone - can do that all the time. But it's a start.
Hmm, even an off center fed dipole would work pretty well, if you can camoflauge it somehow (say, if there's a wooden post about 6 foot high near the end of the balcony)...in theory, you could also put that air band duckie I've heard about on a mag mount, then put that on the balcony. It would be pretty hard to spot... 73 Mike
[edit] Here's the air band duckie I meant...
http://www.universal-radio.com/catalog/scanants/1687.html
As for frequencies, generally speaking 30-50 mhz is all FM - rarely have I seen a report of a milcom freq in this range that was AM. In the 250-270 mhz area, where satellites are heard, freqs can be FM, sideband and other things, too. By and large if you stick with AM in the 225-380 mhz band you will be fine for most apps. However, there are many mil and fed bases moving FM trunks into the 380-390 Mhz area. If you hear control channels in that area you know what you have found.
The 296 cannot trunk these freqs. The 396, 996 and PSR 500 and 600 can. 73 Mike