Why mode A when squawking 7700?
According to my CD-Rom on Air Law, when squawking 7700 (mayday), 7600 (radio failure) or 7500 (unlawful interference), it is to be done in mode Alpha.
The narration says so.
The set in the example picture has an 'Alt' setting which I guess is mode Charlie but is selected to 'On' which I assume is mode Alpha, confirming the narration.
Why not squawk 7700 in mode Charlie during an emergency?