Section VI
Paragraphs 6-8 to 6-18
TABLE 6-1
Table 6-2 (Continued)
FINE FREQUENCY OSCILLATOR
COARSE FREQUENCY OSCILLATOR
Freq.
Inner
Crystal
Freq.
Outer
Crystal
Position
KC
Position
Dial
Dial
KC
4875
.0
124
17
8706.333
1
4900
.1
8791.667
125
18
2
4925
.2
19
8875.000
126
3
4950
.3
8958.333
4
127
20
.4
4975
9041.667
128
21
5
.5
5000
9125.000
6
129
22
.6
5025
9208.333
23
130
7
.7
5050
9291.667
8
131
24
9
.8
5075
132
25
9375.000
.9
10
5100
9458.333
26
133
134
27
9541.667
28
9625.000
135
COARSE FREQUENCY OSCILLATOR
6-8. AUDIO SECTION TROUBLESHOOTING.
Outer
Freq.
Crystal
Dial
Position
KC
6-9. WAVE FORM CHECK. Troubles in the audio
108
1
7375.000
section may generally be isolated to the faulty circuit
by checking wave forms at the AUDIO OUT connector
109
7458.333
2
for the various positions of the AUDIO SELECTOR
switch. Connect an oscilloscope to the AUDIO OUT
110
7541.667
3
connector and compare the waveforms with those
shown below.
7625.000
111
4
6-10. VOR. Appears as a wide sine wave band at 30
7708.333
112
5
cps. See figure 6-1.
113
7791.667
6
6-11.
LOC. Same as VOR except smaller 30 cps
amplitude. See figure 6-2.
7875.000
114
7
6-12. TONE LOC. Appears as a composite 90 and
7958.333
115
8
150 cps wave. Varies in waveform as LOC-GS control
is rotated. See figure 6-4.
8041.667
116
9
6-13. GLIDE SLOPE. Same as TONE LOC except
8125.000
117
10
that amplitude is doubled.
11
8208.333
118
Waveform is that of a 1000 cps
6-14. 1000 CPS.
sine wave.
6291.667
119
12
Wave form is that of a 30
6-15. 30 CPS VAR
8375.000
120
13
cps sine wave.
14
8458.333
121
6-16. 9960 FM. Appears as a 9960 cps sine wave
with the frequency modulation causing a spreading out
122
15
of the wave form. See figure 6-3.
8541.667
123
16
8625.000
6-17. 90 CPS.
Wave form is that of a 90 cps sine
wave.
25
