Wavetek 171 Manual page 7

1.1 THE MODEL 171
The Wavetek Model 171 Synthesizer/Function Generator is
a precision source of sine, triangle and square waveforms
and dc voltage. The generator combines the precision fre-
quency of a synthesizer with the versatility and operating
convenience of a function generator. The two major modes
of operation are synthesizer and function generator.
Function generator output frequency can be varied from
0.1 Hz to 2 MHz in seven ranges manually by dial and re-
motely by an applied voltage. In addition to this analog
control of frequency, the Model 171 has a 4% digit switch
for synthesizer control of function generator frequency.
The synthesizer gives precision (0.005%) frequency accuracy
and stability (0.0001%/°C) from 1.000 Hz to 1.9999 MHz
in six ranges. When the synthesizer is used to set the fre-
quency, in addition to greater frequency accuracy and sta-
bility, the waveform purity is improved over that of the
function generator alone.
Amplitude of the waveform is continuously variable from
10V peak-to-peak in a matching termination load (502 or
6002) down to 10 mV peak-to-peak in four ranges of at-
tenuation (0, 20,40, 60 dB). DC reference of the waveforms
can be offset positively and negatively. The synthesizer can
be locked to its own internal reference or to an external
1 MHz reference.
1.2 SPECIFICATIONS
The available waveforms, frequencies, amplitudes, operating
modes, precision (accuracy) and purity (quality) are listed
in the following paragraphs.
1.2.1 Versatility
Output Signals
Sine "N, , triangle ^v ‚square "L and DC selectable. TTL
pulse ri, 1 MHz reference pulse 71 and GCV signal
proportional to output frequency are also available.
Control
Generator operates in continuous mode. Frequency is
controlled manually by dial or digital switch, or externally
thru VCG input voltage. Digital switch is operable between
0.1000 and 1.9999 settings and works with all frequency
multipliers except X 1.
SECTION
INTRODUCTION
Frequency Range
0.1 Hz to 2 MHz in seven overlapping ranges.
Operating Frequency Ranges
FREQ MULT Range Digital Resolution
X1 0.1 Hz to2 Hz N. A.
X 10 1 Hz to 20 Hz 0.001 Hz
X 100 10 Hz to 200 Hz 0.01 Hz
X 1K 100 Hz to 2 kHz 0.1 Hz
X 10K 1K Hz to 20 kHz 1.0 Hz
X 100K 10K Hz to 200 kHz 10 Hz
X 1M 100K kHz to 2 MHz 100 Hz
NOTE
Digital switch valid with all frequency multipliers
except X 1 (first range). Frequency ratio of
1000: 1 on dial, 20:1 on digital switch.
Main Output
N, ^v , L ; variable to 20V р-р into open circuit and
10V р-р with matching load at either 500 OUT or 60022
OUT. DC offset of waveform (or DC if selected) is adjustable
to +10 volts open circuit and +5 volts into matching load.
Waveform plus offset is limited to +10V peak (open circuit).
Output waveforms can be attenuated from 0 dB to 80 dB:
60 dB in 20 dB steps plus a 20 dB vernier for continuous
variation (20 dB vernier does not affect offset or DC output).
Optional output protection circuit of zeners and fuses protect
both output and common sides from inadvertent connection
to external voltage or ac line.
DC Offset and DC Output
DC offset of waveform and DC output are selectable and
variable thru +10V (+5V into matching load). Waveform
plus offset is limited to +10V peak (open circuit). Step at-
tenuator attenuates dc level.
Generator Frequency TTL Output
TTL pulse has an approximately 50% duty cycle at gener-
ator frequency and can drive up to 20 TTL loads.
Optional TTL buffer circuit provides high power TTL com-
patible signal capable of driving load impedances as low as
500.