SSR Frequency Chg Action RNAV
If, hypothetically, you were squawking 7000 (conspicuity) and were asked by an ATCATC —Air Traffic Control unit to change to 3500, there is a chance you could change the second digit first, meaning for a small amount of time you are squawking 7500 — the code for unlawful interference. Seeing this squawk may cause, shall we say, a certain reaction in ATCATC —Air Traffic Control units that have seen it and may possibly lead to military or other intervention. Therefore, prior to changing any squawk, switch to standby as this means the transponder is on but not responding. You do not need to turn the transponder off.