"A spring loaded switch could be used to select QTE (True Bearing). "
Which is why we always said "True Bearing, True Bearing, True Bearing. Wherever Approach, ABC12, request True Bearing" (rather than just "Anywhere Approach, ABC12, Request Steer") as it gave the Air Trafficker time to reach up for the wiggly-worm switch. Since we navigated over 8/8th cloud using only UDF and Eureka DME, the ATCOs were pretty nimble with their True Bearings back then!
IIRC, there was a mast near Melton Mowbray which was 222 deg True from Cranwell - too good to resist!
And the students who agreed to hold at various points around the compass; when the ringleader pressed the tone button, it meant "Game on"...
1st Student "True Bearing...."
2nd Student "True Bearling...."
3rd Student "True Bearing."
1st Student "Wherever Approach..."
2nd Student "(Fake C/S)..."
3rd Student "Request True Bearing"
