Transponder code selection
Hi all, a quick question, what is the reccomended procedure for dailing in an ATC 'squawk' code. I have seen some pilots select the transponder to Standby , dial in the code and return the transponder to ON/mode 'C', I was taught to select the code once it is given by ATC, because turning the transponder to STBY and back ON gives some kind of alert , don't know what kind , maybe an ATC'er could shed some light.