Sharp GF-500, Service Manual

Page: 10 / 30

BIAS OSCILLATOR FREQUENCY CHECK
1. Make connection of instruments as shown in Fig.
2. Set the function selector switch to “tape” and the beat
cancel switch to “A”.
Record Mode
Oscilloscope
3 . P l a c e t h e u n i t i n r e c o r d m o d e , a n d c h e c k t h a t t h e
frequency counter reads 90
Changing the beat cancel switch from “A” to
position,
see that the frequency counter reading changes by
from the previous value 90 and with the beat
cancel switch set at “C” position, see that it changes by -3
5kHz from previous value 90
Figure
P L A Y B A C K A M P L I F I E R S E N S I T I V I T Y C H E C K
1. Make connection of instruments as shown in Fig.
2 . S e t t h e f u n c t i o n s w i t c h t o “tape”, the volume
control knob to and the treble/bass tone control
knob to “center” position.
Test Tape
MTT-118
3. Play a test tape M T T - 1 1 8 ,
prerecorded).
Head
4. See that the electronic voltmeter reads about
Figure
R E C O R D SENSITIVITY CHECK
Phono input
1.99
Using a CR oscillator, apply a signal of oscillation
( - 5 0 I V )
1 to each input socket of the unit.
Line input
39.8 79mV
2. Check for the input voltage available when the level
( - 2 5 I V )
indicator “OVU” lights up. See Table
External mic input
1.58
( - 5 3
Table
For the radio (high frequency) Circuit adjustment, refer to the GF-54542 Service Manual
or GF-5454 Service Manual