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GNS 400W Series Maintenance Manual
Page 4-35
190-00356-05
Rev. A
Desensitization
Set generator to the desired frequency. Input the following:
•
-87 dBm signal
•
30% modulation
•
1 kHz audio frequency
With the signal generator set to the parameters listed above, the receiver (S+N/N) ratio must not
decrease to less than 6 dB under the following conditions:
In the presence of an unmodulated carrier having a level of -33 dBm at the receiver input
terminals and at frequencies between 108 and 156 mHz, including the frequencies equivalent to
the next higher and the next lower channels to which the receiver can be tuned, but excluding the
frequency range between these two channels.
In the presence of an unmodulated carrier having a level of -7 dBm at the receiver input terminals
and at any frequency within the range 50 kHz and 1215 mHz, except for discrete spurious
response frequencies. This excludes the frequencies within the range 87.5 and 156 mHz. At the
discrete spurious response frequencies, the unmodulated carrier (undesired signal) must have a
level of -33 dBm at the receiver input terminals.
In the presence of an unmodulated carrier having a level of -5 dBm at the receiver input terminals
and at frequencies between 87.5 and 107.9 mHz.
Signal Pin
Signal Name
Reference Pin
Reference Name
Load
J2-7
COMM AUDIO HI
J2-19
COMM AUDIO LO
500 Ohms
Manually test per instructions found in DO186a 2.2.11.
