Earlier this summer, I answered a call on 123.300 from an glider pilot
flying overhead at FL370 asking how things were down there. So, I think
there are still many listening on frequencies we use, and on 121.500.

I also remember hearing Ned Wilson tell of calling a tower on 121.500 and
apologizing because he didn't know their frequency. By all means, use
121.500 if you need it. Tell them it is not life threatening (if indeed
it isn't), and someone will be happy to help.

This same tower had previously (not that day) not responded to calls by a
glider on their frequency. The glider was in their airspace and might be
needing to land at their airport. After his third or fourth call, the
tower responded in a winded voice "Say again calling tower? We were out
watching the glider!"

Steve Leonard