Where did you perform the test flight? If it was sufficiently local, it could be a ground station off-line.
There are a number of plane with metallic paint and trackers so That may not be the [full] problem.
If you know a HAM radio operator and/or can find a radio that will receive 144.39Mhz, you can verify you are transmitting.
Originally Posted by Bill Boyd
he better _be_ a ham operator
Clarification (for smarty people
): "find a HAM operator with lots of useful tech toys like 2M portable radios, antenna and transmitter testers, etc.