Garmin CIRRUS PERSPECTIVE SR20 Line Maintenance Manual page 110

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6. Turn off the PFD and MFD by pulling their circuit breakers.
7. Restart the PFD and MFD in Configuration Mode.
8. On the PFD, turn to the COM SETUP page.
9. Activate the cursor and select the desired tuning frequency using the FMS knobs. Only
the frequencies 118.00, 127.00, & 136.975 may be used when setting squelch and
sidetone levels.
10. Select GIA1 or GIA2 in the COM Setup window. This forces an update of the calibration
data values and must be accomplished prior to making any changes. Failure to do so
may allow COM calibration values to be inadvertently stored into incorrect memory
locations requiring GIA replacement.
11. For 25kHz operation, adjust the SQ 250 value. It may be set to any value between 0
(zero) and 63. The higher the number, the less signal is required to break squelch.
12. For 8.33kHz operation, adjust the SQ 833 value. It may be set to any value between 0
(zero) and 63. The higher the number, the more signal is required to break squelch.
13. After the squelch value is adjusted to the desired number, press the STORE softkey at
the bottom of the display to save the value to the GIA.
14. Repeat steps 7‐11 for tuning additional frequencies.
Page 5-64
Rev. E
Cirrus Perspective™ Line Maintenance Manual
190-00920-00