Garmin GNS 430 - Agc; Selectivity (Bandwidth)

400 SERIES MAINTENANCE MANUAL Page 5-39
P/N 190-00140-05 Rev. C
5.7.5.6 Centering Accuracy
1. Apply a standard glideslope test signal to the unit.
2. Measure GLIDESLOPE +UP (J6-32) with respect to GLIDESLOPE +DOWN
(GLIDESLOPE Common) (J6-31).
3. Verify the centering accuracy is 0 mV r7.8 mV.
 Centering Accuracy _________mV
5.7.5.7 AGC
1. Apply a glideslope centering test signal to the unit.
2. Measure GLIDESLOPE +UP (J6-32) with respect to GLIDESLOPE +DOWN
(GLIDESLOPE Common) J6-31 to find the course deviation.
3. Vary the RF input level between -76 dBm and -33 dBm.
4. Verify the course deviation is 0 r7.8 mV
 Course Deviation _________mV
5. Apply a glideslope deviation test signal to the unit.
6. Measure GLIDESLOPE +UP with respect to GLIDESLOPE +DOWN (GLIDESLOPE
Common) J6-31 to find the course deviation.
7. Vary the RF level between -76 dBm and -33 dBm.
8. Verify the course deviation is 78 r7.8 mV.
 Course Deviation ______mV
5.7.5.8 Selectivity (Bandwidth)
1. Apply the glideslope centering test signal at a level of -87 dBm.
2. Vary the RF frequency r17 kHz from the assigned channel.
3. Measure GLIDESLOPE +UP with respect to GLIDESLOPE +DOWN (GLIDESLOPE
Common) J6-31 to find the course deviation.
4. Verify the course deviation is 0 mV r7.8 mV.
 Course Deviation ______mV @ +17 KHz
 Course Deviation ______mV @ -17 KHz