Maybe a crazy question form a noob.....

So here's the deal. I know nothing about Ham radio. I've been doing a little reading about the Tech license but that's about it. I'm a police officer also. Our local departments, state-county-city, all use different frequencies to talk on and we can't hear each other. So I was thinking about getting a scanner. But then I thought, why not get a radio instead. I was looking at the Yaesu radio's and they can scan, although not transmit, in the police bands (700-999mhz). If I got a Tech license, I could use the radio to scan while I'm patrolling and in my off time I could talk on the lower bands.



Now my question, which may sound silly, but I'm confused regarding the nomenclature regarding 2m, 6m, 10m, 70cm, etc. If for instance, I got a Yaesu RT60, which I believe is a 2m radio, does that mean I can only transmit on a certain set of frequencies and not on the others? or is it simply a matter of hooking up a different length antennae to it? If I attach a longer anntenae can I talk on 10m? Maybe what I'm asking is so far off it doesn't make any sense?



I understand that the there are difference frequencies associated with different antennae lengths, but does that mean you have to have specific radios also?



Can someone explain?



Thanks.

Maybe a crazy question form a noob.....