User's Manual

TY91/TY92 VHF Radio Installation Manual 11 April 2012
00839-00 Issue AA
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36 Trig Avionics Limited
8.4 Tuning Knobs
The right hand knobs are used to tune the radio. The large knob adjusts the
MHz portion of the standby frequency, and the smaller knob adjusts the kHz
portion of the standby frequency.
Pressing the end of the small knob changes the channel spacing that the small
knob operates through. If the radio is configured for 8.33 kHz operation, the
steps toggle between 8.33 kHz channels and 25 kHz channels. If the radio is
configured only for 25 kHz operation, the steps toggle between 25 kHz and 50
kHz channels. Changing the step size does not change the behaviour of the
radio, only the tuning knob step size – it helps to quickly tune a frequency.
8.5 Flip-flop Button
The Flip-flop button swaps the frequency in the standby display, at the bottom
of the screen, into the active position, and moves the active frequency to the
standby position.
8.6 MON Button
The TY91/TY92 includes a dual-frequency listen feature; pressing the MON
button toggles this feature on and off.
When the feature is active, a +2 icon appears next to the standby frequency,
and the radio will scan between the active and standby frequencies listening for
transmissions.
This is useful in an aircraft with only a single radio, since it allows you, for
example, to copy the ATIS whilst maintaining a listening watch on the ATC
frequency.
8.7 MEM Button
Behaviour of the MEM button depends on whether you have a GPS connected
that can load frequencies into the TC90. If you do, then pressing the MEM
button allows access to those frequencies. Turning the LARGE knob steps
through the airports for which frequencies have been loaded. Turning the