Table of Contents
Advertisement
61
— If necessary readjust RV306.
Sometimes it may be necessary to make a compromise between the pulse shapes
in the NORMAL and INVERTED mode.
— Turn the AMPLITUDE FINE control, RV5, to MAX.
— Check that the amplitude is 3.2 V +0.1 V (applies to an instrument which has
been switched on for at least 30 minutes).
— Readjust, if necessary, by replacing resistor R1 across potentiometer RV5 with
another value. The value may vary between 6 kQ and 12 kQ,
i)
a
b
c
MA 6617
Fig's a and b show possible deviations (exaggerated) before adjustment
Fig. c shows correct shape (idealised) after adjustment.
Fig. X-5. Pulse diagram
Waveform distortion
Distortion may be observed on the output pulse when the instrument is set as
follows:
S4 (S9)
AMPLITUDE
+3V
RV5(RV7)_—
Vernier
MAX. (fully clockwise)
RV4(RV6)
DC OFFSET
+1.5.V (fully clockwise)
83
WIDTH
100 ns
58 (S10)
NORM/INV.
NORMAL
At these settings transistors Z339 and Z340 will be saturated and, depending on
their saturation properties, cause distortion. See figure below.
distortion
correct shape
MA6731
Fig. X-6. Pulse diagram
Advertisement
Table of Contents
