The DME is more limited in its operation than some. It has a 4 position switch which as shown, can set the DME either to the selected NAV1 or NAV2 frequency.

It is identified in the usual way using the Audio Box DME selector

The display shows Distance in Nautical Miles, Groundspeed and the frequency in use. There are few "frills" and it is not possible to select a standby frequency as such.

It is however possible to set the switch to the Hold position to retain the frequency currently in use, whilst a new frequency is selected - either on NAV1 or on NAV2.

Some thought and planning (and not a little practice) is necessary in order to gain the most from this instrument. The set is powered by a separate switch to the left