Compère will need this guy before November (4)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

I think this is a triple definition, though the second and third may be intended in combination. Short for microphone, typically used by a compère hosting an event; a man’s name (guy = slang for man); or the code-word for the letter M in the radio alphabet, so immediately before November which represents N.