Yes, if you press F12 you should be transmitting on range (others within a certain range of you should hear you). If you press T you will transmit on the tuned channel on your "v" radio. If you press / to bring up your radios, you can tune the v channel (vox channel) to your own gameid and if you can hear yourself, your radio is working properly.
Just remember to hold the transmit key for a second before and after you talk so you don't cut off the beginning or ending when you speak. If none of this helps you, then I don't know what else could be the problem. If you still can't get it working, perhaps Skuzzy will figure it out when he's in the office during the week.