"tango4" wrote in message
...
Colibri Loggers and LX vario avionics get very unpredictable over 16 volts
( in spite of what the original manuals said - up to 24v iirc ) I had a
Colibri reading over 75000 feet amsl whilst on the runway.

Ian

My Colibri manual, dated Feb. 2001, gives the operating voltage as 10-15
volts.