Wavetek 188 Manual page 10

OSCILLOSCOPE
MODEL 188
еее
(СО) (НІ)
ЕОМСТІОМ СЕМЕВАТОВ
OR VOLTAGE SOURCE
(INITIALLY OFF)
Figure 2-1. First Setup
Amplitude is normally variable over 30 dB for each
output with a 50 dB amplitude range available by
utilizing both outputs.
If simultaneous 6000 and 500 output impedances are
desired:
1. Change value of R148 from 4990 to 6040.
2. Remove R149.
The result is:
HI 10V p-p (500 source) into 509.
LO 10V р-р (6000 source) into 6000.
Amplitude is variable over 30 dB. Square wave rise
and fall time is less than 150 ns. Any value greater
than 6000 may also be substituted for the value of
8148 for other output impedances.
To increase the range of the variable amplitude con-
trol in a modified unit beyond 30 dB, decrease the
value of R124 as necessary. Waveform quality
relative to the standard unit is not guaranteed below
— 30 dB and above 20 kHz.
Table 2-1. Initial Checkout
Step Control Position/Operation Observation
1 | POWER ON + 10V square wave on СНІ and + 1V on СН.
Return to CH1 only.
2 |Dial Rotate in both directions. Return} Rotation сем increases frequency of su Е
іо 2.0.
rotation cw decreases frequency.
3 | FREQUENCY
MULTIPLIER
return to x 1K.
Press each switch sequentially;
Frequency increases in decade steps, left to
right.
4 | AMPLITUDE Rotate ccw. Amplitude decreases.
5 | BG OEESET Rotate cw. Return to OFF.
Output immediately offset negative, then moves
positive. OFF return it to original level.
к
6 | AMPLITUDE Rotate суу.
Square returns to original атр иде.
7 | Function Generator
or DC Voltage nect УСа ІМ input.
„=
Vary input ас voltage; then discon-| Frequency increases with positive voltage апа
decreases with negative voltage.
Source
8 | FUNCTION Pressi Ave sil № Observe Ar , TL , ~ waveforms.
9 | MODE Gate (CONT depressed, А dc level near zero volts (except "L function).
TRIG/GATE released).
10 | MANUAL TRIGGER | Press and hold.
Continuous ^v .
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