Garmin GMA 342 Installation Manual page 57

APPENDIX C INTERCONNECT DRAWINGS
190-01878-02
Revision 5
GMA 342/345 INSTALLATION NOTES
1.UNLESS OTHERWISE INDICATED, ALL SHIELDS MUST BE TERMINATED AT THE GMA END ONLY.
ALL SHIELDS ARE TIED TO THE SHIELD BLOCK OF THE BACKSHELL USING RING TERMINALS.
USE 190-00313-09 FOR GUIDANCE FOR SHIELD TERMINATIONS.
2. UNLESS OTHERWISE NOTED, ALL STRANDED WIRE MUST CONFORM TO MIL-W-22759/16 OR EQUIVALENT.
UNLESS OTHERWISE NOTED, ALL SHIELDED WIRE MUST CONFORM TO MIL-C-27500 OR EQUIVALENT.
3. UNLESS OTHERWISE NOTED, ALL WIRES ARE 22 AWG MINIMUM.
4. SYMBOL DESIGNATIONS AND CONNECTOR GUIDANCE:
WHT
SHIELDED 2 CONDUCTOR
BLU
WHT
SHIELDED 3 CONDUCTOR
BLU
ORN
TWISTED SHIELDED 3 CONDUCTOR
SHIELD FLOATS
AIRCRAFT GROUND
SHIELD BLOCK GROUND TWISTED SHIELDED 2 CONDUCTOR
SHIELD FLOATS
WIRE SPLICE
TWISTED SHIELDED 3 CONDUCTOR
SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS
MOMENTARY CONTACT
PUSH BUTTON
TWISTED SHIELDED 2 CONDUCTOR
SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS
SLEEVE
SLEEVE
TIP TIP
STEREO
PLUG
NOTE 7
RING
TIP
STEREO PLUG TIP
INSERTED INTO
JACK
RING RING
S L E E V E S L E E V E
RING SHORTED
TO SLEEVE
NOTE 5. AUDIO JACK ISOLATION DIAGRAM
AUDIO
FLAT METAL STEREO JACK
JACK
WASHER HEADSET EAR SPEAKER
TIP (LEFT CHANNEL)
RING (RIGHT CHANNEL)
METAL SLEEVE (LO)
NUT
JACK HEADSET MIC
TIP (*PTT)
FLAT INSULATED
RING (MIC HI)
SHOULDER WASHER
SLEEVE (MIC LO)
WASHER
AIRCRAFT PANEL
5. ISOLATE JACK SLEEVE (MOUNTING NUT AND NUT PLATE) FROM AIRCRAFT CHASSIS.
ALL HEADSET, MICROPHONE, AND MUSIC PHONE JACKS MUST BE ELECTRICALLY ISOLATED FROM GROUND.
REFER TO THE FIGURE ABOVE FOR HOW THE JACK IS ISOLATED. NOT ISOLATING WILL CAUSE GROUND LOOPS AND NOISE.
6. THE CONNECTION BETWEEN PTT AND THE MIC JACK TIP IS REQUIRED IF HAND MICS WILL BE USED. *DENOTES AN ACTIVE LOW SIGNAL.
7. THE HEADSET EAR SPEAKER SLEEVE DIAMETER IS 0.25 INCH AND LARGER THAN THE HEADSET MIC SLEEVE DIAMETER 0.206 INCH.
8. IF THE TRANSCIEVER HAS A SEPARATE RETURN FOR AUDIO IN AND AUDO OUT, CONNECT BOTH TO THE GMA AUDIO LO AT THE GMA.
9. DO NOT CONNECT THE SPEAKER GROUND RETURN TO THE AIRCRAFT CHASSIS. THE GROUND RETURN MUST GO TO THE GMA.
10. THE LIGHTING BUS VOLTAGE RANGE IS CONFIGURABLE FOR EITHER 14 OR 28 VOLT SYSTEMS. REFER TO INSTALL MANUAL CONFIGURATION OPTIONS.
11. GARMIN RECOMMENDS USING STEREO HEADPHONES. IF MONO JACKS ARE DESIRED, GARMIN RECOMMENDS THE USE OF THE LEFT
OUTPUT ONLY (LEAVE THE RIGHT CHANNEL UNCONNECTED). DO NOT CONNECT THE LEFT AND RIGHT CHANNELS TOGETHER.
12. THE TELEPHONE INTERFACE MAY BE WIRED TO A FIXED MOUNTED TELEPHONE SOURCE (SHOWN) OR TO A SUITABLE JACK FOR
PORTABLE TELEPHONE.
13. TRANSCEIVER INTERFACES CAN ALSO BE WIRED THROUGH SUITABLE JACKS AND CABLES TO HANDHELD COMS THAT HAVE HEADSET
INTERFACE CAPABILITY. THE HANDHELD'S HEADSET OUTPUT (LEFT CHANNEL ONLY IF STEREO) CONNECTS TO THE GMA'S COM AUDIO
IN HI AND COM AUDIO LO PINS, THE HANDHELD'S MIC INPUT CONNECTS TO GMA'S COM MIC AUDIO OUT HI AND COM AUDIO LO PINS, AND
THE HANDHELD'S PTT KEY CONNECTS TO GMA'S COM MIC KEY* OUT. SEE TRANSCEIVER'S INSTRUCTION MANUAL.
14. * DENOTES ACTIVE LOW.
15. MONO ONLY HEADSET JACK CONNECTION DETAIL.
16. USE A MINIMUM 10 WATT SPEAKER.
USE 8 OHM SPEAKER FOR 28 VOLT SYSTEMS ONLY.
USE 4 OHM SPEAKER FOR 14 OR 28 VOLT SYSTEMS.
17. ICS KEY INPUTS ARE ALSO COMPATIBLE WITH TWO-STAGE PTT KEYS IN WHICH THE FIRST DETENT ACTIVATES THE ICS KEY AND THE
SECOND DETENT ACTIVATES THE TRANSCEIVER PTT (CREW ONLY) FOR THAT POSITION.
18. PLUGGING A MONORAIL HEADSET INTO A STEREO JACK SHORTS THE RIGHT CHANNEL OUTPUT TO GROUND. THIS WILL CAUSE EXCESS CURRENT TO BE
DRAWN. THIS WILL NOT DAMAGE THE GMA, BUT IS NOT RECOMMENDED. THE GMA WILL DETECT THE SHORTED CHANNEL AND SHUT THE AUDIO TO THE SHORTED
CHANNEL OFF TO PREVENT THE INTERNAL AMPLIFIER FROM DRIVING A SIGNAL INTO A SHORT.
19. THE MUSIC LO SIGNALS ARE NOT THE SAME REFERENCE AS OTHER GROUNDS. THE MUSIC LO SIGNALS ARE PART OF A DIFFERENTIAL PAIR WITH THE
RIGHT AND LEFT SIGNALS. IF THE MUSIC LO SIGNAL IS TIED TO A GROUND, THE MUSIC WILL CONTAIN NOISE, AND THE AUDIO QUALITY WILL BE DEGRADED.
20. USE RG400 FOR MARKER BEACON COAXIAL CABLE. THE RF MATING CONNECTION FOR THE ANTENNA (BNC, TNC, N) WILL DEPEND ON THE MARKER BEACON ANTENNA USED
FOR DSUB COAXIAL CABLE INSTALLATION GUIDELINES REFER TO MARKER INSTALLATION SECTION OF INSTALL MANUAL. AVOID SHARP CORNERS AND ROUTE AWAY FROM
HIGH CURRENT WIRING AND ANY TRANSMITTER CABLES.
MONO
PLUG
NOTE 18
MONO PLUG
INSERTED INTO
JACK
NOTE 5
NOTE 7
NOTE 5
NOTE 7
Figure C-1 Notes for Example Interconnect Drawings
GMA 342/345 Installation Manual
Page C-1