Sharp C-1020G Serviceanleitung Seite 15

FM Tracking
(The screwdriver to be used must be non-metallic.)
1.
2:
10.
Take the same step-1. as of the before-mentioned FM IF
adjustment.
Connect a standard dummy antenna to a signal generator
(75 ohm input impedance for the receiver side), and
further connect one of its two teminals to the rod an-
tenna terminal K11 and another to the earth ae
point TP-A2.
. Connect a VI'VM to the speaker output seniinal via a
resistor of 16 ohm.
. Regulate the output level of signal generator to be
30 dB, 22.5 kHz frequency-modulated at. modulation
frequency 400 Hz.
. Set the signal generator to 87.25 MHz. Rotate the radio
tuning knob to tune in the lowerst frequencies (with the
variable capacitor set to "MAX" position), then adjust
the core of LAOQ2 to attain the maximum output: for
this adjustment, the maximum output should never be
taken for that at the side peaks. The volume control
must have been lowered down to the point which
doesn't enable the audio output to saturate.
. Set the signal generator to 109 MHz. Rotate the radio
tuning knob to tune in the highest frequencies (with the
variable capacitor set to "MIN" position), then adjust
the trimmer (CA16) of the variable capacitor which is
coupled in parallel with the LAO2, to achieve the maxi-
mum output. Also here, this maximum output should
never be taken for that at the side peaks.
. Repeat the steps 5. and 6. until the coverage in reception
will be 87.25 MHz to 109 MHz. Upon completion of this
frequency coverage work, finish it up by adjusting the
said trimmer again.
. Set the signal generator to 90 MHz and rotate the radio
tuning knob to tune in this signal. Reduce the output of
signal generator until it gets out of a limiter's operating
effect and adjust the core of LAO1 to achieve the maxi-
mum output.
. Set the signal generator to 106 MHz and rotate the radio
tuning knob to tune in this signal. As in the step 8, re-
duce the signal generator's output and adjust the
trimmer (CA04) which is coupled in parallel with the
LAO], to attain the maximum output.
Repeat the steps 8. and 9. to reach a perfect tracking.
Upon completion of this tracking, finish it up by adjust-
ing the said trimmer again.
MW Tracking
(The screwdriver to be used must be non-metallic.)
1.
2.
ON
10.
16
Take the same procedure as of ""AMIF Adjustment 1.".
Connect a standard loop antenna to the signal generator
and positionally arrange the loop antenna and MW coil
of the bar antenna as shown in Fig. 17.
. Connect VTVM to the output terminal of speaker
through a resistor of 16 ohm.
. Set the signal generator to be approx. 70 dB, 30% fre-
quency-modulated at modulation frequency 400 Hz.
Next, set the volume control to "MAX" position and ad-
just the output of signal generator to have the sound
output be 50 mW.
. Set the signal generator to 515 kHz and rotate the radio
tuning knob to tune in the lowest frequencies, adjust the
core of TA04 to provide the maximum output.
. Set the signal generator to 1,650 kHz and rotate the
radio tuning knob to tune in the highest frequencies.
Then, adjust the trimmer (CA62) of the variable capaci-
tor which is coupled in parallel with the TA 04, to pro-
vide the maximum output.
. Repeat the steps 5. and 6. until the frequency coverage
will range from 515 kHz to 1,650 kHz. Upon comple-
tion of this frequency coverage, finish it up by adjusting
the said trimmer again.
. Set the signal generator'to 600 kHz and rotate the radio
tuning knob to tune in this signal. Then, reduce the out-
put of signal generator to become low (by about 70 dB)
enough to be got rid of AGC operating effect and posi-
tionally adjust the bar antenna's MW coil to attain the .
maximum output.
. Set the signal generator to 1,400 kHz and rotate the
radio 'tuning knob to tune in this signal. Next as in the
step 8, reduce the output of signal generator, and adjust
the trimmer of the variable capacitor (CA48) which is
coupled in parallel with the bar antenna coil, to achieve
the maximum output.
Repeat the steps 8. and 9. so that the tracking will be
perfect. Finish it up by adjusting the said trimmer again.
Loop Antenna
Figure 17.