Figure 4-8. AN/PRR-S(XE-9) if. selectivity test.
i. Return AN/GRM-50 to 455 kHz and tune each
d. Adjust the receiver volume control for squelch
side of 455 kHz until the ME-26/U indicates 0.6 volts
"off" and midposition.
difference from reference level noted in step f. above.
e. Adjust the AN/GRM-50 output for 500
j. Note and record the 0.6 volt difference
frequency, as indicated on the AN/USM-207.
f. Note and record the voltage reading on the ME-
k. Determine the Af, and Af, of each 0.6 volt
26/U. This is the reference level for the test.
g. Vary the frequency of the AN/GRM-50 on each
I. The asymmetry ratio of the discriminator shall
side of 455 kHz until the ME-26/U indicates maximum
not exceed 1.3:1.
difference from the reference level noted in step f.
h. Note and record the frequencies at which
maximum difference occurs, as indicated by the
AN/USM-207. The peak to peak separation shall be at
least 40 kHz.