Garmin GNC 420 GPS Receiver User Manual


 
Page 5-32 400 SERIES MAINTENANCE MANUAL
Rev. C P/N 190-00140-05
5.7.4 Navigation Assembly I/O Tests
5.7.4.1 Localizer Course Deviation Test
1. Display the VOR/LOC/GS CDI Test Page (Figure 5-6).
Figure 5-6. VOR/LOC/GS CDI Test Page
2. Display the following on the VOR/LOC/GS CDI Test Page and verify the following voltages,
measuring across VOR/LOC +LEFT (J6-3) with respect to VOR/LOC +RIGHT (J6-4).
Full Right ___________ (-150 ±15 mV)
Standard Right ___________ (-90 ±9 mV)
Centered ___________ (0 ±4.5 mV)
Standard Left ___________ (+90 ±9 mV)
Full Left________ (+150 ±15 mV)
5.7.4.2 To/From Deflection Output Characteristic Test
Verify the TO/FROM (VOR/LOC +TO) output is capable of driving up to three meter loads of
200 ohms each.
5.7.4.3 To/From Deflection Accuracy Test
1. Display TO.
2. Measure VOR/LOC +TO J6-1 with respect to VOR/LOC +FROM J6-2.
3. Verify the following output:
TO/FROM (VOR/LOC +TO) ______ (225
r
75 mV)
4. Display FROM.
5. Measure VOR/LOC +TO J6-1 with respect to VOR/LOC +FROM J6-2.