Does your school have a network analyzer? If so, you could hook a couple of the antennas up to it, and determine their frequency response, impedance, etc. (you're looking for the frequency range where the antenna impedance is about the same as the line impedance--probably 75 ohms).
Chances are, there's a frequency somewhere in that region that you can legally transmit on; if not, you can always use stub-matching to get acceptable performance at further-away frequencies.