User's Manual

TY91/TY92 VHF Radio Installation Manual 11 April 2012
00839-00 Issue AA
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Trig Avionics Limited 37
SMALL knob then steps through the individual frequencies for that airport.
After you have stepped through all the loaded airports, or if there is no GPS
attached, the built-in memory of the TC90 is displayed.
The TC90 has nine frequency memories. Each frequency position can be
selected by turning the SMALL tuning knob.
Whether from a GPS or from the onboard memory bank, the selected
frequency is loaded into the standby window. Pressing MEM again leaves the
stored frequency in the standby window. Pressing the Flip-flop button loads
the stored frequency directly into the active channel.
To store a frequency in one of the memory locations it must first be tuned and
active. Press MEM to enter the memory mode in the usual way. Select the
channel you want to overwrite with the tuning knobs. Now press, AND
HOLD, the MEM button for 2 seconds. The current active frequency will be
moved to the selected memory location, overwriting the existing contents.
8.8 General Low Temperature Operation
The TY91/TY92 is certified to operate correctly down to -20°C, but at low
temperatures the controller display may be impaired. On a cold day you may
need to wait for the cockpit to warm up to ensure normal operation.
8.9 Warning Messages
If the VHF radio detects a problem, the screen will indicate WARNING and a
brief statement of the problem. Depending on the nature of the problem, your
VHF radio may not be working properly. Note the message on the screen and
pass that information to your avionics maintenance organisation. Press ENT to
clear the message; if the fault is still present the message will reappear.
8.10 Fault Annunciation
If the VHF radio detects a catastrophic internal failure, the screen will indicate
FAULT and a brief statement of the problem. No replies will be made to
interrogations when a fault has been detected.