In article ,
Roy Smith wrote:

Sometime later, you realize you havn't heard from them for a while and
upon calling, get no response.

Jim had a good answer, but you might try broadcasting your intentions
blind in case they can hear you. I had a radio failure on the way to
my private checkride and got a green light from the tower surprisingly
fast. Turns out they could hear me even though I couldn't hear them.
After shutting down and talking to the examiner we tried it again and
the problem went away, at which point the tower said they'd heard all of
my calls. I bet that was annoying, too, since I used every combination
of 2 radios and 2 headset jacks and the hand mic!

--
Ben Jackson

http://www.ben.com/