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SECTION 5. REFERENCE OSCILLATOR
FREQUENCY CALLIBRATION
Your DG-5 was completely aligned at the
factory. However, the reference oscillator fre-
quency sometimes may deviate with secular
change. In such an event, calibrate it as directed
below.
CAUTION
Before calibration, wait over one
hour for the DG-5 to warm up after
power-on.
1.
Set the TS-520S BAND switch to WWV to
receive the 15MHz standard wave.
2.
Connect the supplied signal cable from the
DG-5 CAL connector to the TS-520S X
VERTER IN connector as shown in Figure
7. The fifteenth harmonic of the DG-5
reference oscillator fundamental,
1
MHz,
will superimpose on the 15MHz WWV
signal. Then you will hear of an impure,
double beat.
3.
Adjust the trimmer located inside the
bottom cover using an adjust screwdriver
until the impure beat becomes clear, as
shown in Figure 7. For more precise adjust-
ment, the S meter on the TS-520S is helpful.
The S meter pointer will vibrate finely on
either side of the true calibration point.
As the reference oscillator frequency comes
close to the calibration point, the pointer
deflection becomes large and slow. When
it is largest and slowest, set the trimmer.
ANT
1
S7
DG-5
COUNT IN
HET VFO CAR CAL
-1-
0
0 0 0
13.8 V
ADJUST SCREWDRIVER
TS-520S
COUNTER
0 00
0 0 °
0
0
X VERTER')
IN
0
0
120 /220 V
Figure 7. Reference Oscillator Calibration.
11
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