190-01879-11
GMA 245/245R Installation Manual
Revision 6
Page C-1
APPENDIX C
INTERCONNECT DRAWINGS
Figure C-1 Notes for Example Interconnect Drawings
GMA 245 INSTALLATION NOTES
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:
SHIELDED 2 CONDUCTOR
WHT
BLU
SHIELDED 3 CONDUCTOR
TIP
SLEEVE
RING
STEREO
PLUG
TIP
SLEEVE
MONO
PLUG
NOTE 7
TIP
TIP
RING
RING
E
V
E
E
L
S
E
V
E
E
L
S
STEREO PLUG
INSERTED INTO
JACK
MONO PLUG
INSERTED INTO
JACK
RING SHORTED
TO SLEEVE
WHT
BLU
ORN
TIP (LEFT CHANNEL)
RING (RIGHT CHANNEL)
SLEEVE (LO)
NOTE 5
NOTE 7
STEREO JACK
HEADSET EAR SPEAKER
TIP (*PTT)
RING (MIC HI)
SLEEVE (MIC LO)
NOTE 5
NOTE 7
JACK HEADSET MIC
AIRCRAFT GROUND
SHIELD BLOCK GROUND
WIRE SPLICE
MOMENTARY CONTACT
PUSH BUTTON
NOTE 5. AUDIO JACK ISOLATION DIAGRAM
AIRCRAFT PANEL
SHOULDER
WASHER
FLAT INSULATED
WASHER
FLAT METAL
WASHER
METAL
NUT
AUDIO
JACK
5. ISOLATE JACK SLEEVE (MOUNTING NUT AND NUT PLATE) FROM AIRCRAFT CHASSIS.
7. THE HEADSET EAR SPEAKER SLEEVE DIAMETER IS 0.25 INCH AND LARGER THAN THE HEADSET MIC SLEEVE DIAMETER 0.206 INCH.
6. THE CONNECTION BETWEEN PTT AND THE MIC JACK TIP IS REQUIRED IF HAND MICS WILL BE USED. *DENOTES AN ACTIVE LOW SIGNAL.
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
14. * DENOTES ACTIVE LOW.
15. MONO ONLY HEADSET JACK CONNECTION DETAIL.
16. USE A MINIMUM 10 WATT SPEAKER.
1.UNLESS OTHERWISE INDICATED, ALL SHIELDS MUST BE TERMINATED AT THE GMA 245 END ONLY.
ALL SHIELDS ARE TIED TO THE BACKSHELL USING RING TERMINALS. FOR GMA 245, USE THE RING
TERMINAL ADAPTERS PROVIDED FOR THE BACKSHELLS IN THE CONNECTOR KIT. FOR GMA 245R,
CONNECT RING TERMINALS TO THE BACKSHELLS. FOR BOTH UNITS, #8 SCREWS, WASHERS, AND SPLIT
WASHERS ARE PROVIDED.
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.
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.
TWISTED SHIELDED 3 CONDUCTOR
SHIELD FLOATS
TWISTED SHIELDED 2 CONDUCTOR
SHIELD FLOATS
TWISTED SHIELDED 3 CONDUCTOR
SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS
TWISTED SHIELDED 2 CONDUCTOR
SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS
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.
NOTE 18
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. IF THE GMA IS AT THE END OF THE CAN BUS, ADD GPN 011-03002-00 CAN TERMINATION KIT TO THE CAN BUS AS SHOWN.
ONLY INSTALL CAN TERMINATION KIT IF THE GMA IS AT THE END OF THE CAN BUS. THE TERMINATION STUB LENGTH SHOULD NOT EXCEED 0.3 METERS.
IT IS RECOMMENDED THAT THE GMA BE LOCATED IN THE MIDDLE OF THE CAN BUS SO A TERMINATION KIT IS NOT NEEDED.
THE TERMINATION KIT IS AN OPTIONAL ACCESSORY.
