Many years ago entering the Mirabel QC Canada control zone at 0600 with a 206L helicopter:
"Mirabel Tower C-GUXT"
Silence
" Mirabel Tower Charlie Golf Uniform X-ray Tango"
Silence
"Mirabel Tower UXT?"
Silence
"Mirabel, Mirabel, Mirabel -UXT?"
Silence
"Houston - Apollo 13 - with a problem!"
Reply
"Aircraft calling Mirabel- say again"
It all worked out from there -being as there had probably been no AC movements since 0030 local completely understandable.
I was not fully awake myself.
Night shift is a bitch - used to work in a smelter in Northern Quebec and after 0400 it was always a problem to stay awake if nothing was happening.