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400 SERIES MAINTENANCE MANUAL
Rev. C
P/N 190-00140-05
5.7.5.9
Nose Bandwidth
1.
Apply standard glideslope test signal to the unit (-56dBm).
2.
Find the AGC voltage and use it as a reference.
3.
Vary the input signal frequency over the range of
r
17 kHz from the assigned channel
frequency.
4.
Verify the input signal level needed to maintain the AGC reference voltage level does not
vary more than 6 dB.
Input Signal Level Variance______ <6 dB @ +17 KHz
Input Signal Level Variance______ <6 dB @ -17 KHz
5.7.5.10
Skirt Bandwidth
1.
Apply standard glideslope test signal to unit at a signal amplitude of –93dBm.
2.
Find AGC voltage and use as a reference.
3.
Increase signal level to –33 dBm.
4.
Vary selected frequency
r
132 kHz.
5.
Verify the AGC voltage is less than the reference AGC voltage from step 2.
AGC Reference Voltage______ dB @ +132 KHz
AGC Skirt Voltage______ dB @ -132 KHz
5.7.5.11
Spurious Response
1.
Tune the Glideslope receiver to 335 MHz.
2.
Apply a 335 MHz signal at a –87dBm level.
3.
Measure the AGC Voltage and use it as a reference.
4.
Remove the test signal.
5.
Apply an undesired image frequency test signal of 245 MHz with a 150 Hz signal, amplitude
modulated at 30%.
6.
Verify the RF level of the undesired image frequency test signal of 245 MHz shall be greater
than –27 dBm to produce an AGC level equal to that of a desired frequency having a level of
–87 dBm.
AGC Reference Voltage___________should be greater than -27 dBm image AGC
voltage