Figure 1-2 Gtx 335 Front Panel - Garmin GTX 335 w GPS Installation Guidance

NOTE
If the transponder is in the ON or ALT operating mode, the transponder becomes an active
part of the Air Traffic Control Radar Beacon System (ATCRBS). The transponder will reply
to interrogations from aircraft with TCAS installed.
Key Selection Functions for GTX 335:
OFF
SBY
ON
ALT
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Rev. 1

Figure 1-2 GTX 335 Front Panel

Turn off the GTX 335.
Selects the Standby mode. Push the STBY key when the GTX 335 is
powered off to automatically energize the unit on in standby mode. When
in standby mode, the transponder does not reply to any interrogations but
new codes can be put in and a SBY indication will show on the display.
Selects the On mode, which gives Mode A and Mode S replies, but Mode
C altitude reporting is prevented. Push the ON key when the GTX 335 is
powered off to automatically energize the unit in Mode A, and transmit a
squawk code when interrogated. ADS-B Out will not return barometric
altitude as it switches to GPS altitude while in this mode. Interrogations
are shown by the reply symbol (R). For On mode, the replies do not
include altitude information.
Altitude mode is automatically selected when the aircraft becomes
airborne, using the units air/ground logic, or when the ALT key is pushed.
Push the ALT key when the GTX 335 is powered off to automatically
energize the unit in altitude reporting mode. While the aircraft is on the
ground and in ALT mode, the transponder does not give Mode A and
Mode C replies, but it does give acquisition squitter and replies to
discretely addressed Mode S interrogations.
While the aircraft is in ALT mode and airborne it will give Mode A,
Mode C, and Mode S replies and give transmissions of acquisition and
extended squitter, to include ADS-B Out.
All transponder interrogation replies are shown by the Reply symbol (R).
VFR Sets the transponder code to the pre-programmed VFR code
selected in Configuration mode (set to 1200 at the factory). Push the
GTX 335 w/GPS Installation Guidance
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