I use the control tower to guide me to airports. Recently, right after being asked by the controller to inform him/her when the field is in sight, the controller will tell me he is "out of range" and that I should "switch to another frequency" which is usually not available. It doesn't matter what airport I'm approaching. I know it worked before, but the issue occurred in the past few days. Please help.
Also, my altimeter constantly has a reading of 100,000 ft and I don't know how to change it or reset it. Any ideas?