Wavetek 180 User manual

I
INSTRUCTION MANUAL
MODELS 180 AND 180 LF
SWEEP/FUNCTION
GENERATORS
SWeEP-FUMCTiONGf^NLRATOR 180
St«F»:P«A! E on OFFSET FREQMULT^Hij S^.EEPWIOTH
I
smi.c PUISEOUT
iTTt
^ m m
SWEEP/FUNCTION GENERATOR MODtc jeotF
SWeiPRATE DC OFFSET
FRtQMUtT iH*l SWEEPWIDTH
\ f Tj
\ r /
WR<
AMPLtrUDE
PULSE OUT
ITTL)
WVas/'

WARRANTY
All Wavetek instruments are warranteed against defects in material and workmanship for a period
of one year after date of manufacture. Wavetek agrees to repair or replace any assembly or
component (except batteries) found to be defective, under normal use, during this period.
Wavetek's obligation under this warranty is limited solely to repairing any such instrument which in
Wavetek's sole opinion proves to be defective within the scope of the warranty when returned
to the factory or to an authorized service center. Transportation to the factory or service center
is to be prepaid by purchaser. Shipment should not be made without prior authorization by
Wavetek.
This warranty does not apply to any products repaired or altered by persons not authorized by
Wavetek, or not in accordance with instructions furnished by Wavetek. If the instrument is
defective as a result of misuse, improper repair, or abnormal conditions or operations, repairs will
be billed at cost.
Wavetek assumes no responsibility for its product being used in a hazardous or dangerous manner
either alone or in conjunction with other equipment. High voltage used in some instruments may
be dangerous if misused. Special disclaimers apply to these instruments. Wavetek assumes no
liability for secondary charges or consequential damages and, in any event, Wavetek's liability for
breach of warranty under any contract or otherwise, shall not exceed the purchase price of the
specific instrument shipped and against which a claim is made.
Any recommendations made by Wavetek for use of its products are based upon tests believed to be
reliable, but Wavetek makes no warranty of the results to be obtained. This warranty is in lieu of
all other warranties, expressed or implied, and no representative or person is authorized to
represent or assume for Wavetek any liability in connection with the sale of our products other
than set forth herein.

INSTRUCTION MANUAL
MODELS 180 AND 180 LF
SWEEP/FUNCTION
GENERATORS
\\^\VETEK
Box 651, San Diego, Calif., 714-279-2200
3/77

CONTENTS
SECTION 1 GENERAL DESCRIPTION
1.1 THE MODELS 180 AND 180LF
1.2 SPECIFICATIONS
SECTION 2 INITIAL PREPARATION
2.1 UNPACKING INSPECTION
2.2 PREPARATION FOR USE
2.3 ELECTRICAL ACCEPTANCE CHECK
2.4 CHANGING THE OUTPUT IMPEDANCE . .. .
SECTION 3 OPERATION
3.1 CONTROLS AND CONNECTORS .
3.1.1 Power/Frequency Controls
3.1.2 Amplitude Controls
3.1.3 Function Selections
3.1.4 Sweep Controls
3.2 OPERATION
3.2.1 Signal Termination
3.2.2 Manually Controlled Operation
3.2.3 Voltage Controlled Operation
3.2.4 Sweep Generator Operation
SECTION 4 CIRCUIT DESCRIPTION
4.1 VOLTAGE CONTROLLED GENERATOR (VCG)
4.2 FREQUENCY CONTROL
4.3 WAVEFORM OUTPUT
4.4 SWEEP CIRCUITS
4.5 CRYSTAL CONTROL
SECTION 5 CALIBRATION
5.1 FACTORY REPAIR
5.2 REQUIRED TEST EQUIPMENT
5.3 REMOVING GENERATOR COVER
5.4 CALIBRATION
SECTION 6 TROUBLESHOOTING
6.1 FACTORY REPAIR
6.2 TROUBLESHOOTING CHART
6.3 TROUBLESHOOTING INDIVIDUAL COMPONENTS
SECTION? PARTS AND SCHEMATICS
7.1 DRAWINGS
7.2 ORDERING PARTS
7.3 ADDENDA
1-1
1-1
2-1
2-1
2-1
2-1
3-1
3-1
3-1
3-2
3-2
3-2
3-2
3-3
3-3
3-4
4-1
4-1
4-2
4-2
4-2
5-1
5-1
5-1
5-1
6-1
6-1
6-1
7-1
7-1
7-1

1
SECTION
GENERAL DESCRiPTION
1.1 THE MODELS 180 AND 180LF
The Wavetek Model 180 Sweep/Function Generator is a
precision source of sine, triangle, and square waveforms.
Frequency of the waveforms is manually and remotely
variable from 0.1 Hz to 2 MHz. The generator can repeti
tively sweep from one frequency to a higher frequency,
with controllable rate and range of sweep. Amplitude of
the waveforms is variable from 10V peak-to-peak into 50f2
down to 30 mV p-p. DC reference of the waveforms can be
offset positively and negatively.
A voltage representing generator frequency, a fixed
amplitude pulse train of that frequency, and a voltage ramp
representing frequency sweep rate are provided as front
panel outputs.
The Wavetek Model 180LF (Low Frequency) Sweep/Func
tion Generator is identical to the Model 180 except for
frequency range: 0.01 Hz to 200 kHz.
1.2 SPECIFICATIONS
The specifications (available waveforms, frequencies, and
amplitudes), operating modes, precision (accuracy), and
purity (quality) are listed in the following paragraphs.
1.2.1 Versatility
Output Signals
Sine % , triangle
ramp ^ and DC.
square ""Lj , TTL pulse J~L
Control
Generator operates in continuous and sweep modes. Fre
quency controlled manually or with external voltage.
Frequency Range
0.1 Hz to 2 MHz (180); 0.01 Hz to 200 kHz (180LF).
Operating Frequency Ranges
Model 180:
XI 0.1 Hz to 2 Hz
X 10 0.1 Hz to 20 Hz
X100 0.2 Hz to 200 Hz
X IK 2 Hz to 2 kHz
XIOK 20 Hz to 20 kHz
X 100K 200 Hz to 200 kHz
X 1M 2 kHz to 2 MHz
Model 180LF:
X.I 0.01 Hz to 0.2 Hz
X I 0.01 Hz to 2 Hz
X 10 0.02 Hz to 20 Hz
X100 0.2 Hz to 200 Hz
X IK 2 Hz to 2 kHz
X10K 20 Hz to 20 kHz
X 100K 200 Hz to 200 kHz
Main Output
Sine, triangle and square waveforms and DC are selectable.
HI (0 dB) and LO (-20 dS) BNC outputs are available for
simultaneous usage; outputs may be varied to HI (—30dB)
and LO (—50 dB) by amplitude control. HI output provides
20V peak-to-peak max open circuit (10V peak-to-peak max
into 50n load). LO output provides IV peak-to-peak max
into 50n load. Both output impedances are 50^2.
DC Offset and DC Output
DC offset of waveform and DC output selectable and variable
through HI and LO BNC outputs. HI output ±10V max
(±5V into 50n load) as offset or Vdc output. LO output
±1V max into 50n load as offset or Vdc output. Waveform
offset limited to ±10 Vp HI and ±1 Vp LO (both open
circuit voltages).
Pulse Output
TTL pulse (50% duty cycle) at generator frequency. Drives
up to 20 TTL loads.
GCV Output
0 to +2V (nominal, open circuit) proportional to frequency
of main generator. Output impedance 600J2.
VCG — Voltage Controlled Generator Input
VCG voltage as well as control settings select generator
frequency. Frequency may be dc-programmed or ac-mod-
ulated by external 0 to 2V signal. Input impedance is 2 kS7.
VCG input can change generator output 1000:1 on all
ranges except X 10 Hz and X 1 Hz ranges (Model 180) and
X 1 Hz and X .1 Hz (Model 180LF).
VCG Input Signal Bandwidth; 100 kHz.
VCG Slew Rate: O.IVZ/JS.
1-1

Sweep Output
Ramp waveform output with 5V peak into open circuit.
Output impedance 600n.
1.2.2 Operating Modes
Continuous
Operates as standard VCG. Frequency of main generator
determined by dial/range setting and VCG input voltage.
Sweep
Main generator is frequency modulated by internal sweep
generator. When swept, main generator frequency rises from
frequency set by the dial and range setting to a frequency
set by sweep width control.
Sweep Rate: 30 ms to 20s (nominal) continuously adjustable
by single turn control on front panel.
Sweep Width: Up to 1:1000 adjustable on all ranges except
X 1 Hz and X 10 Hz ranges (Model 180) and X .1 Hz and
X 1 Hz (Model 180LF).
1.2.3 Horizontal Precision
Dial Accuracy
Model 180: ±3% of full scale for 0.1 Hz to 2 MHz.
Model 180LF: ±3% of full scale for 0.01 Hz to 200 kHz.
Time Symmetry
Models 180 and 180LF, as applicable: ±1% on all but
X 1M range.
1.2.4 Vertical Precision
Amplitude Change With Frequency (Sine)
Models 180 and 180LF, as applicable:
Less than ±0.1 dB on all ranges thru X 100K.
Less than ±0.5 dB on X 1M range.
1.2.5 Waveform Purity
(Models 180 and 180LF, as applicable)
Sine Distortion
Less than 0.5% on X 100, X 1K, X 10K ranges (typically
0.2%).
Less than 1.0% on X 1, X 10, X TOOK ranges (typically
0.5%).
All harmonics 30 dB down on X 1M range.
Square Wave Rise and Fall Time
Less than 75 nanoseconds.
Triangle Linearity
Greater than 99% to 200 kHz.
1.2.6 Environmental
Specifications apply at 25°C ±5°C. Instrument will operate
from 0°C to +50°C.
1.2.7 Mechanical
Dimensions
11% in./28.6 cm wide; 4 in./10.2 cm high; lOVa in./26.7 cm
deep.
Weight
6.5 lb/2.9 kg net; 9.5 lb/4.3 kg shipping.
1.2.8 Power
105 to 125V or 200 to 250V, 50 Hz to 400 Hz. Less than
15 watts.
NOTE
AH specifications apply when frequency dial is
between 0.1 and 2.0, amplitude is at 10V p-p
and output is from HI BNC into 500. load.
1-2

2
SECTION
INITIAL PREPARATION
2.1 UNPACKING INSPECTION
After carefully unpacking the instrument, inspect the ex
ternal parts for damage to knobs, dials, indicators, surface
areas, etc. If there is damage, file a claim with the carrier
who transported the instrument. Retain the shipping con
tainer and packing material for use in case reshipment is
required.
2.2 PREPARATION FOR USE
Before connecting the instrument to line power, check that
the rear panel 115/230V switch is set to the value nearest
the line voltage and that the fuse is correct for the switch
setting. Check that the plug on the power cord is the mate
for the line receptacle.
2.3 ELECTRICAL ACCEPTANCE CHECK
This checkout procedure provides a general verification of
generator operation. Should a malfunction be found, refer
to the Warranty in the front of this manual.
An oscilloscope, BOH coax cable, and a 50f2 feedthru are
needed for this procedure (figure 2-1). Preset the generator
front panel controls as follows:
Control
Position
FREQMULT PWR OFF
Frequency Dial l.Q
Function
AMPLITUDE Full clockwise
DC OFFSET OFF
SWEEPWIDTH OFF
SWEEP RATE 9 o'clock
Perform the steps in table 2-1; monitor the 50n OUT HI
connector at the oscilloscope.
2.4 CHANGING THE OUTPUT IMPEDANCE
The output impedance is normally:
HI 50n@10Vp-p
LO 50J2 @ 1V p-p
Attenuation is normally 0 - 30 dS. Lowest possible ampli
tude is —50 dB.
If simultaneous BOOH and 50n output impedances are
desired:
MODEL 180
50L2„
LOAD
OUT®
Clh
OSCILLOSCOPE
Figure 2-1. Acceptance Check Setup
1. Change value of R145 from 49912 to 604S2.
2. Remove R147.
The result is:
HI 5012 @ 10V p-p
LO 60012 @ 10V p-p (low power)
Attenuation is 0 - 30 dB. Lowest possible amplitude is
—30 dB. Square wave rise and fall is < 150 ns.
If 5012 and any other impedance greater than 60012 are
desired, replace R145 with resistor of that value.
If 50 dB of attenuation control is desired in a modified
instrument, change R121 from 33.212 to 1.812. Waveform
quality above 20 kHz will be considerably impaired at
-50 dB compared to a standard instrument.
2-1

Table 2-1. Acceptance Check
Step Control Position/Operation Observe at 50SJ OUT
1
FREQMULT X 1 (Model 180)
X .1 (Model 180LF)
1 Hz, 10V p-p sine wave (Model 180)
0.1 Hz, 10V p-p sine wave (Model 180LF)
2
FREQ MULT
X 1, X 10, X 100, - - - X 1M
(as applicable)
Frequency increases by a decade for every change of
switch position
3
FREQ MULT
X IK
4
Function Triangle wave
5 Function "b Square wave
6 AMPLITUDE ccw Decrease in waveform amplitude
7
DC OFFSET
cw Positive slew of waveform from full negative offset
8
DC OFFSET ccw Negative slew of waveform
g
DC OFFSET OFF
10
AMPLITUDE Full cw
11 Dial Full cw
12 SWEEP WIDTH Full cw Frequency of waveform repetitively sweeps
2-2

3
SECTION
OPERATiON
3.1 CONTROLS AND CONNECTORS
The generator front panel controls and connections shown
in figure 3-1 are keyed by circled numbers to the following
descriptions.
3.1.1 Power/Frequency Controls
(T) FREQMULT/PWR OFF
Power is turned on when frequency range is selected
at the FREQ MULT (Hz) control. The ranges
multiplied by frequency dial settings deter
mine output frequency. The frequency dial index
lights when power is turned on.
(2) Frequency Dial
Frequency dial settings multiplied by frequency
range determine output frequency.
VCG IN Connector
Voltage controlled generator input (VCG IN) dc
excursions proportionally control frequency within
a selected range. Positive inputs increase frequencies
set by the frequency dial and range control; nega
tive inputs decrease the frequencies.
GCV OUT Connector
Generator controlled voltage output (GCV OUT)
dc excursions of OV to about 2V proportionally
represent output frequency within a given range.
3.1.2 Amplitude Controls
@ DC OFFSET
Rotating the DC OFFSET control clockwise offsets
dc center reference of waveform positive; when
POWER/FREQUENCY
FREQ
UlTiH/t
SWEEP WiOTH
SWEEP
AMPLITUDE
© @ ®
SWEEP/FUNCTION
a'VEEPRATE DC Of
\ ^ iiv
F \ / OFF
\GCV jTSiNeBP PULSE OUT
OUT / OUT (TTLI I
ENERATt
DEL 180
FUNCTIONS
Figure 3-1. Model 180 Controls and Connectors
3-1

counterclockwise, negative. When OFF, the wave
form is balanced around signal ground (figure 3-2).
TTL PULSE
Figure 3-2. Output Waveforms
@ AMPLITUDE
Rotating the AMPLITUDE control fully clockwise
provides maximum peak-to-peak output at the
50n OUT connectors; counterclockwise for up to
30 dB attenuation of output amplitude.
50n OUT Connectors
Maximum output of 10V p-p signals into a 5012
load (20V p-p open circuit) is provided at the
50n OUT HI connector, and 20 dB below (1/10
or a 1V p-p maximum) of that level at the 5012 OUT
LO connector.
3.1.3 Function Selections
(D %
Tj , and DC (Waveforms)
Sine 'V , triangle 'V , and square ""L wave
forms are selected by the larger of the two concen
tric controls; the DC position provides a dc voltage
output of the waveform center reference level at
the 5012 OUT connectors.
@ TTL PULSE OUT Connector
A fixed amplitude Transistor-Transistor Logic
(TTL) square pulse train of the output frequency
is provided at the PULSE OUT (TTL) connector.
(TTL levels are OV to 0.4V for a logic low and
2.4V to 5V for a logic high.) The output can drive
up to 20 TTL loads. The pulse train can also be
used as a synchronizing reference for the main
output @ . Phase of the waveforms relative to
the TTL pulse is shown in figure 3-2.
3.1.4 Sweep Controls
@ SWEEP WIDTH/OFF
Main output (at 5012 OUT HI or LO) frequency
sweep is turned on when SWEEP WIDTH is rotated
past OFF. Rotation of the control varies the peak
amplitude of an internal ramp signal (seen at GCV
OUT) whose voltage controls the frequency of the
main generator (seen at 5012 OUT). See figure 3-3.
. SWEEP TIME
GCV
OUT
5012
OUT
SWEEP START
FREQUENCY SET BY
FREQUENCY DIAL
SWEEP
WIDTH
SWEEP STOP
FREQUENCY SET BY
SWEEP WIDTH
Figure 3-3. Effect of Sweep on Output Frequency
SWEEP OUT Connector
The sweep generator ramp is available at the
SWEEP OUT connector. Amplitude is OV to 5V
peak (60012 source impedance).
SWEEP RATE
Rotation of SWEEP RATE controls duration of
the sweep voltage ramp, and thus frequency of
sweep repetition.
3.2 OPERATION
Operation can be quite varied but is described here as
manual, voltage controlled or sweep controlled. The gen
erator is ready to operate as soon as a frequency multiplier
is selected; however, when output is critical, allow Vi hour
warm up.
3.2.1 Signal Termination
Proper signal termination, or loading, of the generator con
nectors is necessary for its specified operation. For example,
the proper termination of the main output is shown in
figure 3-4. Placing the 50 ohm terminator, or 50 ohm
resistance, in parallel with a higher impedance, matches
the receiving instrument input impedance to the generator
3-2