Originally Posted by
disctilt
Can anyone explain what the definition of a DME X-channel is. I have searched the web for a few hours and have found varying definitions.
I am studying for JAA ATPL and have ground school notes that tell me:
An X-channel is where the response from the (X-channel) ground transponder is 63MHz higher than the interrogators request frequency
and that
a Y-channel DME responds 63MHz lower than the interrogators.
I have found evidence that this is incorrect and that it is in fact the other way around (i.e. that the X-Channel DME responds 63 MHz lower). Can someone please tell me which is correct
The ground based DME responder will respond to pulse pairs in the first 63 channels (1025-1088MHz) at -63MHz for X channels and +63MHz for Y. This reverses for the upper 63 channels (1089-1213MHz)