Go find a guard in a boring place and go talk to him, then say "oh we use those radios, but they barely work in our building" and get a real good look at the antenna.
Is it a V/U long/short wide/thin 800/900 1.2G ?
What brand/model?
Or, our belt clips keep breaking, are yours plastic or metal?
Or battery life is better with lithium and super light (are your batteries light or heavy), antennas snap off when on the belt.
A friend had motorola "push to talk" phone and 2-way in one. 800mhz. Looked like a modern FRS radio.
Have a close-call in you pocket, and be there if he checks in.
Many check in 5-mins to the hour, and 10 after. Be there then.
If he talks or others do, are there repeater sounds in-between, chirps, digitized voice or analog?
Be creative, pack a lunch, report back and earn your badge.