Epson PX-8 Technical Manual page 269

REV.-A
(2) Adjustment
Check the output signal from the test connector (or the RDSP signal of pin 5 on CN 1) with an
oscilloscope. Turn the azimuth adjustment screw clockwise or counterclockwise until the
peak position of the wave is found, then adjust the azimuth according to the following proce-
dure. (For the location of the adjustment screw, see Fig. 6-20.)
1. Turn the adjustment screw slightly in a counterclockwise direction to deviate from the peak.
2. Slowly turn the adjustment screw clockwise to the peak position. (Be sure to adjust the screw
to the peak position turning it clockwise.)
3. Lock the adjustment screw.
Set the oscilloscope near the following range.
Sweep DIV. 200 J1S
Reference: Output signal of pin 7 of IC4 on MAP-MC board.
The signal wave form should be about
200 mVP-P as shown in Fig. 6-19.
G .....
--I---+-I----t~__1l--1l---'t--t___t__f_-t-
Fig.6-19
6.6.3 Tape Speed (2.4 cm/s)
Make sure, by using the AZIMUTH test tape, that the output is within a range of 3 kHz ± 15 Hz
(as directly measured with a frequency meter). Make sure that the signal at pin 3 of IC2 on the
MAP-MC board is in a frequency range within 400 Hz
±
4 Hz (a pulse cycle range from 2.57 to
2.44 ms). If either deviates from the specified range, readjust the tape speed with variable resistor
VR 1 on the board.
Location
Azimuth adjustment screw
(Located right beneath the azimuth
hole cover.)
Fig. 6-20
6-14