Table 3-4-Continued
Step
Procedure
Normal indication
Possible cause of malfunction
Corrective measure
10
Note digital counter readout at
Frequency display on digital
Defect within digital counter.
Refer to digital counter manual
zero beat and record five most
counter.
significant figures, fH.
11
Tune frequency converter to next
Zero beat on oscilloscope and fre-
Defect within digital counter.
Refer to digital counter manual
lower zero beat and record five
quency display on digital counter.
most significant figures, fL.
12
Divide fH by fH-fL,. to obtain
Digital counter indicates frequency
Defect within digital counter.
Refer to digital counter manual
harmonic number of fL. Set
of signal source no. 2.
HARMONIC PRESET selec-
Frequency converter set to incor-
Repeat 6 through 12.
tor switches to harmonic num-
rect harmonic number.
her of fL, and read frequency
of signal source no. 2 directly
on counter display.
13
Tune frequency converter to fH.
Frequency display is the same as
Harmonic preselector switches set
Repeat 6 through 13.
Reduce setting of harmonic
obtained in 12 above.
too high.
selector switches by 1. Verify
the indication obtained in 12
above with the indication
shown directly on counter dis-
play.
14
When a correct readout is ob-
1/2- to 3/4-inch stable display on
Defect within frequency converter.
Refer to frequency converter
tained, set AFC switch to ON
built-in cathode ray tube.
manual.
ADD 1 MC. Adjust gain con-
trol for a 1/2- to 3/4-inch ver-
tical presentation on built-in
cathode ray tube.
15
Adjust main and FINE TUNING
Built-in cathode ray tube displays
Defect within frequency converter.
Refer to frequency converter
controls to obtain 1:1 Lissa-
a 1:1 Lissajous pattern.
manual.
jous pattern on built-in cath-
ode ray tube.
16
Record indication displayed on
Digital counter displays frequency
Defect within digital counter.
Refer to digital counter manual.
counter.
1 MHz lower than frequency of
signal source no. 2.
17
Multiply counter readout obtained
Frequency of point of interest on
in 16 above by appropriate
response curve of unknown pas-
harmonic number.
sive device is obtained
3-10
