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
pressed, it will stay in the "in" position. Press the switch again and it be in the "out" posi-
tion 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 se-
lected audio on the cockpit speaker when this switch is selected. NOTE: The speaker am-
plifier 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 con-
nected 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 func-
tion 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 trans-
ceiver he is using.
When switching the mic selector rotary switch from C
OM
1 to C
OM
2, while C
OM
2 re-
ceive 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 se-
lected, Com 1 audio will be switched off. In essence, switching the mic selector will not
effect the selection of Com audio.
