Garmin GNC 420 Maintenance Manual page 88

5.7.5 Glideslope Final Tests
5.7.5.1 Glideslope Course Deviation Output Characteristic Test
1. Apply a standard course deviation input signal to the unit.
2. Measure GLIDESLOPE +UP (J6-32) with respect to GLIDESLOPE +DOWN (J6-31).
3. Verify the deviation output voltages (GLIDESLOPE +UP) for the following conditions.
Full Scale Deflection
________ mV (150 ±15 mV)
Greater than Full Scale Deflection (0.4 ddM input signal):
________ mV (300 ±30 mV)
5.7.5.2 Course Deviation Deflection Accuracy Test
1. With a standard deflection 'FLY DOWN' condition (90 Hz dominant), verify the output is
-78 ±7.8 mV.
'FLY DOWN'______ mV
2. With a standard deflection 'FLY UP' condition (150 Hz dominant), verify the output is
+78 ±7.8 mV.
'FLY UP'______ mV
5.7.5.3 Course Deviation Flag Test
1. Select Flag 'HIDDEN'.
2. Verify the course deviation flag output is 375 ± 80 mV.
Course Deviation Flag ______ mV
3. Select Flag 'IN VIEW'.
4. Verify the course deviation flag output is 0 mV ±25 mV.
Course Deviation Flag ______ mV
400 SERIES MAINTENANCE MANUAL
P/N 190-00140-05
(0.175 ddM input signal):
Page 5-37
Rev. C