Frequency control at your club
We have a Plexiglass board and right underneath the Number board is shelves for the transmitters. Pretty basic. You take a pin, clamp it on the number you're using and then leave with your transmitter. IF you're planning on flying, then there's 4 colored cards. Red, yellow green and blue. There's 4 pilot boxes. red yellow green and blue. if you want to fly out of an empty box, then you take that colored boxes coordinating card, and clamp that with your pin to the number you're using. Then you own the box, and the frequency. We had pins engraved with our names on them and our frequency number so no matter what you know what number they're using, what box they're in, and who they are. Not fool proof, and not much different than most clubs, but it's worked so far for us. I think the most surest way to avoid a mishap is to double check every one. "Hey, you got yer pin up?" whether you know if they do or don't. And then it just becomes habit. one hands gets the radio off the shelf, and the other is posting the pin.