190-01182-02
GTR 225/GNC 255 TSO Installation Manual
Rev. F
Page 6-16
6.5 Ground Checks (Configuration Mode)
The following checks are performed in configuration mode, see section 6.4.
6.5.1
Calibrate Resolver (GNC Only)
It is necessary to calibrate the interface between the GNC and the resolver after selecting RESOLVER as
the CDI indicator head type on the CDI INDICATOR page, figure 6-10. The accuracy of the system is
dependent on this calibration. The GNC cannot drive multiple resolvers at the same time. It is not
recommended that external resolvers be switched through a relay or other means because the resolver must
be calibrated to the radio. If multiple resolvers are desired in the installation, the primary unit must be
installed and calibrated as described here. The secondary unit should use the composite output.
To calibrate:
1. Turn outer knob to NAV CONFIGURATION.
2. Turn inner knob to CAL RESOLVER.
3. Press
ENT
.
4. Follow the directions on the GNC display.
Figure 6-24 Calibrate OBS Resolver Page
5. At the end of setup, press
ENT
to store results.
6. Tune to any VOR frequency.
7. Press
OBS
.
8. Verify that the OBS decoded properly from 0 to 360 degrees.
If the GNC will not accept the calibration, there may be a problem with the resolver interface. Verify
wiring and contact Garmin for assistance, if necessary.
