190-01007-A1
System Maintenance Manual GTN 6XX/7XX Part 23 AML STC
Rev. 5
Page 2-1
2 SYSTEM DESCRIPTION
2.1 Equipment Descriptions
2.1.1 GTN 6XX/7XX Navigators and GMA 35
The GTN (Garmin Touch Navigation) WAAS navigators are a family of aviation panel mounted retro-fit
products. The following sections will describe the available functions for each unit in the GTN 6XX/7XX
navigators.
2.1.1.1 GTN 6XX
The GTN 6XX WAAS navigators are a family of panel-mounted GPS/NAV/COM navigators.
The GTN 6XX units include the GTN 625, GTN 635, and GTN 650. They are 6.25 inches wide and 2.65
inches tall. The GTN 6XX features a 600 by 266 pixel color LCD touchscreen. The GTN 625 is a GPS/
SBAS unit that meets the requirements of Technical Standard Order TSO-C146c and may be approved for
IFR en route, terminal, oceanic, non-precision, and precision approach operations when installed in
accordance with the instructions in the manuals referenced in the GTN AML STC. The
GTN 635 includes all of the features of the GTN 625 in addition to an airborne VHF communications
transceiver. The GTN 650 includes all of the features of the GTN 625 in addition to an airborne VHF
communications transceiver and airborne VOR/localizer (LOC) and glideslope (G/S) receivers.
2.1.1.2 GTN 7XX
The GTN 7XX WAAS navigators are a family of GPS/NAV/COM aviation panel-mounted products. The
GTN 7XX units include the GTN 725 and GTN 750. The GTN 7XX units are 6.25 inches wide and 6.00
inches tall. They feature a 600 by 708 pixel color LCD touchscreen. The GTN 725 is a GPS/SBAS unit
that meets the requirements of Technical Standard Order TSO-C146c and may be approved for IFR en
route, terminal, oceanic, non-precision, and precision approach operations when installed in accordance
with the instructions in the manuals referenced in the GTN AML STC. The GTN 750 includes all of the
features of the GTN 725 in addition to an airborne VHF communications transceiver and airborne VOR/
localizer (LOC) and glideslope (G/S) receivers. The GTN 725 and 750 also have the ability to remotely
control GMA 35 audio panel functions.
2.1.1.3 GMA 35 Audio Panel
The GMA 35 audio panel is both a marker beacon receiver and an audio panel with 6-place intercom that
interfaces to the communications and navigation radios, headsets, microphones, and speakers. The
GMA 35 is remote-mounted and relies upon the GTN 725 or GTN 750 to control and display the audio
functions.
The GMA 35 interfaces to the GTN 7XX via RS-232 for control and display of audio panel functions.
Additionally, the GMA 35 includes a six-position intercom system (ICS) with electronic cabin noise de-
emphasis, two stereo music inputs, and independent pilot, copilot, and passenger volume controls. The
intercom provides three selectable isolation modes. A pilot-selectable cabin speaker output can be used to
listen to the selected aircraft radios or to broadcast PA announcements.
2.1.2 NAV Antenna Cable Splitter
The navigation antenna cable splitter (Garmin P/N 013-00112-00) is used for installations involving dual
VHF navigation capable GTNs or a single VHF navigation capable GTN installation with a second
non-Garmin aviation unit.
2.1.3 NAV Antenna Cable Diplexer
The GTN 650/750 navigation units have a single navigation antenna port and thus require a composite
signal for those installations which include separate VOR/LOC and G/S antennas. The navigation diplexer
(Comant diplexer VOR/GS, Model CI-507) is used for these installations.
