PS Engineering PMA7000CAP Installation Manual - Manual (Page 19)

PS Engineering
PMA7000M-S Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual for Civil Air Patrol
200-072-0004 Page 3-2 Rev. 4, Sept. 2000
the "in" position. Press the switch again and it be in the "out" position and remove that receiver
from the audio.
3.2.1 Speaker Amplifier
The "SPR" 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: The speaker amplifier is not
active in the "Split Mode."
3.3 Power Switch (Fail Safe Operation)
Unit power is turned on and off by pushing the volume knob. In the OFF or " FAIL - SAFE " position,
the pilot is connected directly to Com 1. This allows communication 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 power switch also controls the audio selector panel functions, intercom, and marker beacon
receiver. Unless the mic selector is in Com 3 mode, at least one of the selected audio LEDs will
be on (Com 1 or Com 2).
3.4 Microphone Selector
When the mic selector switch is in the Com 1 position, both pilot and copilot will be connected
to the Com l transceiver. 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 the Com 2 transceiver.
The PMA7000M-S gives priority to the pilot’s PTT. If the copilot it transmitting, and the pilot
presses his PTT, the pilot’s microphone will be heard over the selected transmitter.
Turning the mic selector fully counterclockwise places the pilot and copilot on Com 3. Com 3
receive audio is automatically placed in the headset (and speaker if selected). Com 1 and/or
Com 2 receiver audio can be selected to monitor those transceivers. The COM 3 button will
illuminate, indicating that Com 3 receive audio is present.
The PMA7000M-S-Series has an automatic selector mode. Audio from the selected
transceiver is automatically heard in the headsets and speaker. You can check this function by
switching from C
OM 1 to C OM 2 and watch the selected audio indicator change from COM 1
to COM 2. This ensures the pilot will always hear the audio from the transceiver he is using.
When switching the mic selector rotary switch from C OM 1 to C OM 2, while C OM 2 receive
audio had been selected, Com 1 receiver audio will continue to be heard. This eliminates the
pilot having to switch Com 1 audio back on with the receive audio button, if desired.
When switching from C OM 1 to C OM 2 while Com 2 receiver audio 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.