PS Engineering PMA8000B Pilot's Manual And Operation Manual page 12

There are three special functions. Function Button "A" is related to
the intercom function, and allows the crew to mute passengers' inter-
com feed when radios are active.
Function Buttons "B" and "C" control how music is distributed in
your airplane.
Function A
AUX
Intercom Mode
State 1 State 2
"
"
Standard
Alternate
Intercom
intercom
Function"
"
function
There are two music sources available to the PMA8000B. Music 1
input can be either on the front jack, OR the Music 1 input at the rear
connector (Pins 23 and 24, J2). Music 2 is wired into the rear connec-
tor, only (Pins 26 and 27, J2)
The volume of the audio annunciations and recorder playback can be
adjusted through a hole on the top of the unit marked "ANN VOL."
Function "A"
Function "A" controls the distribution of aircraft radio within the in-
tercom, as well as passenger intercom muting. In the "standard inter-
com function" mode, aircraft radios are distributed to all, when the
intercom is in the ALL mode. In CREW mode, only the pilot and co-
pilot positions will hear aircraft radios.
When Function A is toggled into "Alternate Intercom Function," the
passengers will NOT hear aircraft radios, even in the All mode. In
addition, when in the ALL mode, passengers will be able to converse
with the crew. However, when the aircraft radio becomes active, the
intercom audio from the passengers is muted, allowing the crew to
focus on the radio. Passengers will be able to talk to each other,
unless the radios are active AND the crew speaking on the intercom,
in this case the passengers will only hear the crew intercom, and their
microphone will be muted.
Page 12
Function B
MUTE
Music 1
Propagation
State 1 State 2
"Music #1 "Music
all head- #1 distri-
sets" bution
crew."
Button Function Table
202-890-0202 PMA8000B
Function C
SPR
Music Distribution
State 1 State 2
"Alternate
"
Standard
music
Music
distribu-
Distribu-
tion "
tion
Pilot Guide Rev. 7