General Description; The Model 143 , 1·1; Specifications - Wavetek 143 Instruction Manual

1.1 THE MODEL 143
The Model 143 20 MHz Function Generator is a precision
source of sine, triangle and square waveforms, negative and
positive pulses and de levels. All are front panel and external
control variable from 0.0001 Hz to 20 MHz and can be
modulated, swept or de controlled over a 1000: 1 range by
an external voltage. Output can be continuous or the gener-
ator can be triggered or gated by an external voltage or front
panel switch.
The waveform amplitude can be varied up to 30 volts peak-
to-peak (open circuit) and attenuated up to 80 dB. Pulse
amplitude can be varied from ±15 volts peak (open circuit).
DC voltage or de offset of signal is variable by front panel
control and by external control between ±15 volts (open cir-
cuit). Waveform symmetry is variable from 19:1to1 :19 for
control of duty cycle and ramp rise/fall times. Triggered
waveform start/stop point is adjustable for creation of spe-
cial waveforms such as the haversine. A voltage representing
generator frequency and a TTL level sync pulse at the fre-
quency of the generator are auxiliary outputs.
1.2 SPECIFICATIONS
1.2.1 Versatility
Waveforms
Selectable sine
"v ,
square
'1 ,
triangle
"v ,
positive
square n . negative square u , TTL sync pulse and de.
Symmetry of waveforms may be varied for sawtooth and
variable duty cycle pulses.
Operational Modes
Continuous: Generator oscillates continuously at selected
frequency.
Triggered: Generator is quiescent until triggered by an
external signal or manual trigger. then generates one cycle
at selected frequency.
Gated: As triggered mode, except generator oscillates for
the duration of the gate signal.
SECTION
1
GENERAL DESCRIPTION
Frequency Range
0.0001 Hz to 20 MHz in 10 overlapping ranges with 1%
vernier control.
Function Output
"v,
'1 ,
"v
selectable and variable to 30V p-p ( 15V p-p
into 50!1).
n , u ,
to 15 Vp (7.5 Vp into 50!1). All
waveforms and de can supply 150 mA peak current and
may be attenuated to 60 dB in 20 dB steps with an additional
20 dB vernier.
DC Output and DC Offset
Selectable thru FUNCTION OUT output. Controlled by
front panel control or by applying an external voltage. Ad-
justable between ±15 Vdc (±7.5 Vdc into 50!1) with signal
peak plus offset limited to ±15 Vdc (±7.5 Vdc into 50!1).
External offset sensitivity approximately -1 VIV with
output into open circuit. DC offset and output wave-
form attenuated proportionately by the 60 dB output
attenuator.
Sync Output
A TTL level pulse. Will drive 50!1 termination.
GCV - Generator Controlled Voltage
At GCV OUT connector, a 0 to +2V signal proportional to
generator frequency. 600!1 source impedance.
VCG - Voltage Controlled Generator
Up to 1000: 1 frequency change with external 0 to 2 volt
signal to VCG IN connector. Upper and lower frequencies
limited to maximum and minimum of selected range.
Slew rate: 2% of range per µs.
Linearity:
±0.2% for 10 Hz to 100 kHz.
±0.75% for 0.001 Hz to 2 MHz.
Input Impedance: 2 kl1.
Trigger and Gate
Input Range: 1V p-p to ±10V.
Impedance: 10 k!l, 33 pF.
Pulse Width: 25 ns minimum.
Repetition Rate: 10 MHz maximum.
Adjustable Triggered Signal Start/Stop Point (sine and tri-
angle only): Approximately -90° to +90° to 2 MHz.
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