Garmin SL10 - Manual (Page 13)

UPS Aviation Technologies
SL10 Series Audio Selector Panel and Intercom System
User’s Guide
Page 9
If using an external marker receiver, the audio input is lower connector,
pin 11 (Aux. input).
1.6.3 Receiver Sensitivity
Although the SL10M meets FAA TSO-C35d sensitivity specifications,
the sensitivity of the receiver has been adjusted to meet real world
requirements (150
mV and 1400mV Soft). This will usually eliminate the
need for the avionics shop to reduce the sensitivity in the field so as to
prevent early detection of the marker beacons. If your particular
installation requires more or less sensitivity, please call the factory for
details on how to adjust the receiver sensitivity in the field.