GMA
340 Installation Manual
Page B
-15
(Page B
-16
blank)
190-
001
49
-01
Rev L
Figure B7. J2 INTERCONNECT WIRING DIAGRAM
PILOT HEADSET RETURN
AIRCRAFT PWR
PA MUTE
8 OHM SELECT
TONE ENABLE
(RESERVED, do not use)
ICS MUTE INHIBIT
SWAP RETURN
COPILOT MIC KEY*
PASS 4 MIC RETURN
PASS 2 MIC RETURN
PASS 1 MIC RETURN
J2
PTT
Cabin Speaker
See note 9
See note 7
Aircraft Power Buss
5A
1
31
16
2
4
3
34
33
32
35
36
37
38
39
40
41
42
24
23
25
27
26
28
44
43
Mute Trigger to EXT PA
13
14
20
21
12
17
19
18
8
9
10
11
5
6
7
15
22
29
30
14.
W
H
EN
NO
AIRCRAFT
RADIO
ACT
IVIT
Y
IS
D
ET
ECT
ED
BY
T
H
E
G
M
A
340,
T
H
E
A
M
O
UNT
OF
AM
BIENT
BACKGRO
UND
NO
ISE
FR
OM
T
H
E
R
A
D
IO
S
IS
F
UR
T
H
E
R
RE
DUC
ED
BY
T
H
E
M
ASQ
CI
RCU
IT
.
IF
T
H
IS
F
UN
CT
IO
N
IS
N
OT
DESI
RED
,
T
H
E
N
J
1
P
IN
16,
M
ASQ
IN
H
S
HOU
LD
BE
T
IED
T
O
G
R
OUN
D
.
T
HI
S
NOT
E
D
O
E
S
N
O
T
A
PPLY
T
O
T
H
E
F
OLLO
W
IN
G
G
M
A
340
SER
IA
L
NUM
BER
S:
94900000
T
O
9490
0499
AND
9
6
2
50000
TO
96250399.
15.
T
H
IS
NOT
E
APPLIES
ONLY
T
O
UNIT
S
CONFORM
ING
T
O
M
O
D
LEVEL
1.
NORM
AL
M
O
DE:
W
HEN
T
HIS
PIN
IS
TIE
D
TO
GROUND,
T
R
ANSM
IT
T
ING
(KEY
ING)
ON
ANY
COM
W
ILL
CAUSE
T
H
E
O
T
H
E
R
T
W
O
COM
A
UDIOS
T
O
BE
M
U
T
E
D
DU
RI
NG
T
H
E
T
RAN
SM
IT
.
SPLI
T
C
O
M
M
ODE
:
W
H
E
N
T
H
IS
P
IN
IS
T
IED
T
O
G
R
OU
ND,
NEI
T
H
E
R
C
O
M
1
AUDI
O
N
OR
CO
M
2
AUDIO
W
ILL
BE
M
U
T
E
D
D
URI
NG
A
N
Y
T
R
A
NS
M
IT
.
CO
M
3
A
UDI
O
W
IL
L
O
NLY
B
E
M
U
T
E
D
W
H
E
N
T
HE
PI
LOT
T
R
A
N
S
M
IT
S
.
16.
2
S
T
A
GE
M
O
M
E
NT
ARY
S
W
IT
CH.
FIRST
DET
E
NT
:
K
EY
E
D
INT
ERCOM
.
SECOND
DET
ENT
:
M
ICROPHONE
AUDIO
AND
P
T
T
A
C
T
IV
E
.
P
RO
VID
ES
K
E
Y
E
D
INT
ERC
O
M
IN
H
IG
H
N
O
ISE
EN
VIR
ONM
E
N
T
S
.
SECOND DETENT, FULL ACTIVATION (TX)
MICROPHONE LO
MIC
MIC KEY
MIC RETURN
340
DUAL
ADF
MICROPHONE HI
FIRST DETENT, (ICS)
DME Radio
See note 8
See note 12
See note 4
See note 4
See note 4
See note 15
PASS 1 MIC
PASS 2 MIC
PASS 3 MIC RETURN
PASS 3 MIC
PASS 4 MIC
MUSIC 1 RETURN
MUSIC 1 R
MUSIC 1 L
DME RETURN
DME IN
SPKR RETURN
SPKR OUT
See note 6
ICS MUTE INHIBIT RETURN
SWAP
AIRCRAFT PWR
AIRCRAFT GND
AIRCRAFT GND
COM TX MUTE
NC
NC
NC
PILOT HEADSET R
PILOT HEADSET L
14V LGT LO / 28V LGT LO
14V LGT HI / 28V LGT HI
14V LGT HI / 28V LGT LO
COPILOT HEADSET RETURN
COPILOT HEADSET R
COPILOT HEADSET L
COPILOT MIC RETURN
COPILOT MIC IN
HI MUSIC GAIN SELECT
See note 17
13A.
Headset L
IF
GENE
RAL AVIATION MONOPHONIC
HEADS
ETS HAVING
TRUE MONOPHONIC
PLUGS ARE
USED IN
AN
INST
ALLATION
HA
VING
STEREO
HEA
DPHONE
JACKS, THE
RING CONDUCT
OR
WILL
BE
SHORTED TO THE
B
A
RREL CONDUCT
OR
WHEN
THE HEADSET
IS
PLUGGED IN.
THIS WILL NOT
DAMAGE
THE GMA 340.
HOW
EVER,
THIS
WILL
PREVENT PROPER
FA
ILSA
FE OPERATION.
ADDITIONALLY, SINCE THE PASSE
NGE
R HEADSETS
ARE CONN
ECTE
D IN
PARALLEL, ALL
PA
SSENGERS WILL LOSE
ONE
CHANNEL IF
A MONO
HEADSET
IS
PLUGGED
INT
O
A P
ASSENGER P
O
SITION.
TO
AVOID
THIS,
S
T
ERE
O/MONO SWITCHES MAY
B
E
INS
TALLED
AS SHOWN BELOW.
WHEN A MONO HEA
DSE
T
IS
USED, THE
SWITCH MUST BE SET TO THE
OP
EN POS
ITION.
Switch open for mono
Headset Return
Headset R
NOTES PERTAINING TO J1
AND J2
(Cont
’d)
GMA 340
NOTE 13A APPLIES TO GMA 340
UNIT
S
WITHOUT
MOD
4.
NOTE
13B APPLIES
TO
GMA 340
UNITS WITH MOD 4.
13B.
IF UNIT MOD 4
IS
INCORPORATED,
THE ABOVE
CONDITIO
NS
STILL REMAIN EXCEPT
THAT MOD 4
ENSURES PROPER
FAILSAFE
OPERA
TION
F
O
R BOTH
S
T
ERE
O AND MONO
H
EADS
ETS WITHOUT REQUIRING A STERE
O/MONO SWIT
CH.
17.
CONNECT TO GROUND FOR TIMES
TEN
(20 dB) GA
IN,
OR IN
STALL SWITCH TO SELECT
BE
TWEEN UNITY GA
IN (0
dB)
AND TIMES TEN GA
IN (20
dB) FOR MUSIC1.
THIS FUNCTION APPLIES ONLY
T
O
UNITS WITH MOD 5
INCORPORATE
D.
