UPS Aviation Technologies
SL10 Series Audio Selector Panel and Intercom System
User’s Guide
Page 2
1.2.1 Speaker Amplifier
The "S" in the push-button section stands for speaker. This switch will
place all selected audio on the cockpit speaker when this switch is
selected. NOTE: with the exception of unswitched unmuted inputs
(Altimeter warning), the speaker amplifier is not active in the "Split
Mode." To reduce power consumption and internal heat buildup in the
avionics stack, switch off the speaker amplifier when not in use.
1.3 Mic Selector Switch (Fail Safe Operation)
Unit power is turned on and off by the Mic
selector switch. In the OFF or "FAIL-SAFE"
position, the pilot is connected directly to Com
1 allowing transmit and receive capability
regardless of unit condition. Any time power is
removed or turned OFF, the audio selector will
be placed in the fail-safe mode. The first
position clockwise from OFF is COM 1. Both
pilot and copilot will be connected to the Com
l transceiver. While in the COM 1 or COM 2
mode, the intercom functions normally. Both
the pilot and copilot have transmit capabilities
on the selected transceiver. All hear the selected audio if the intercom is
in the ALL mode. Only the person who presses their Push To Talk (PTT),
will be heard over the aircraft radio. Turning the rotary switch to the
COM 2 position will place pilot and copilot on Com 2.
The SL10-Series has an automatic selector mode. Audio from the
selected transceiver is automatically heard in the headsets and speaker
(when selected). You can check this function by switching from COM 1
to COM 2 and watch the selected audio light on the selector change from
C1 to C2. This ensures the pilot will never transmit on a radio is not
listening to.
In SL10-series units, Serial Number T03092 and above, when switching
the mic selector rotary switch from COM 1 to COM 2, while COM 2 audio
had been selected, Com 1 audio will continue to be heard. This
eliminates the pilot having to switch Com 1 audio back on, if desired.
When switching from COM 1 to COM 2 while Com 2 has NOT been
selected, Com 1 audio will be switched off. In essence, switching the mic
selector will not effect the selection of Com audio.
Important: When the mic selector is in the full counter clockwise
position, the SL10 power is removed, and it is in the FAIL-SAFE mode.
The pilot headset and microphone is connected directly to Com 1.
Figure 2
Mic Selector
