EZ Digital FG-7005C User manual

Bench-top Instrument
FG-7005C
Sweep Function Generator
Operation Manual
88 88

WARRANTY
Warranty service covers a period of one year from the date of original purchase.
In case of technical failure within one year, our service center or sales outlet free of
charge will provide repair service.
We charge customers for repair after the one-year warranty period has been
expired. Provided that against any failure resulted from the user’s negligence,
natural disaster or accident, we charge you for repairs regardless of the warranty
period.
For more professional repair service, be sure to contact our service center or sales
outlet.

Introduction
Thank you for purchasing a EZ product. Electronic measuring instruments
produced by EZ Digital are high technology products made under strict quality
control. We guarantee their exceptional precision and utmost reliability. For proper
use of the product, please read this operation manual carefully.
Digital Co., Ltd.
Note
1. To fully maintain the precision and reliability of the product use it within the range
of standard setting( temperature 10 °C~35 °C, humidity 45%~85%)
2. After turning of power, please allow a pre-heating period of as long as some 10
minutes before use.
3. This equipment should be used with a triple line power cord for safety.
4. For quality improvement the exterior design and specification of the product can
be changed without prior notice.
5. If you have further questions concerning use, please contact the EZ Digital
service center or sales outlet
Safety Summary
Please take a moment to read these operating instructions thoroughly and
completely before operating this instrument. Pay particular attention to WARNINGS
used for conditions and actions that pose hazard to the user and CAUTIONS used
for conditions and actions that may damage the instrument.
 Always to inspect the instrument and other accessories for any sign of damage
or abnormality before every use.
 Never ground yourself and keep your body isolated from ground.
 Never touch exposed wiring, connections or any live circuit conductors.
 Do not install substitute parts or perform any unauthorized modification to the
instrument.
 Use caution when working above 60V DC or 30V AC rms. Such voltages pose
a shock hazard.
 Remember that line voltage is present on some power input circuit points such
as on-off switches, fuse, power transformers, etc., even when the equipment is
turn off.
 Also, remember that high voltage may appear at unexpected points in defective
equipment.

CONTENTS
1. PRODUCT DESCRIPTION ----------------------------------------------------------- ( 2 )
1-1. Introduction ----------------------------------------------------------------- ( 2 )
1-2. Technical Specifications ------------------------------------------------- ( 2 )
1-3. Equipment Ratings -------------------------------------------------------- ( 3 )
1-4. Supplied Accessories ---------------------------------------------------- ( 4 )
2. INSTALLATION -------------------------------------------------------------------------- ( 5 )
2-1. Initial Inspection ----------------------------------------------------------- ( 5 )
2-2. Connecting Ac Power ---------------------------------------------------- ( 5 )
2-3. Cooling And Ventilation -------------------------------------------------- ( 5 )
2-4. Position ---------------------------------------------------------------------- ( 5 )
2-5. Warming-Up ---------------------------------------------------------------- ( 5 )
3. OPERATION ------------------------------------------------------------------------------ ( 6 )
3-1. Controls, indicators and connectors ---------------------------------- ( 6 )
3-2 Operating instruction -------------------------------------------------- ( 8 )
3-3. Use As Function Generator --------------------------------------------- ( 8 )
3-4. Use As Pulse Generator ------------------------------------------------- ( 11 )
3-5. TTL/CMOS Output -------------------------------------------------------- ( 12 )
3-6. Use As FM Signal Generator ------------------------------------------- ( 13 )
3-7. External Control Of VCF ------------------------------------------------- ( 14 )
3-8. Programmed Frequency Selection ------------------------------------ ( 15 )
3-9. Use As Sweep Generator ----------------------------------------------- ( 15 )
3-10. Use As Externally Controlled Sweep Generator ----------------- ( 16 )
3-11. Use As External Frequency Counter -------------------------------- ( 16 )
4. MAINTENANCE ------------------------------------------------------------------------- ( 17 )
4-1. Fuse Replacement -------------------------------------------------------- ( 17 )
4-2. Adjustment And Calibration --------------------------------------------- ( 17 )
4-3. Cleaning and Decontamination ---------------------------------------- ( 17 )
5. OTHERS ----------------------------------------------------------------------------------- ( 18 )
5-1. Introduction ----------------------------------------------------------------- ( 18 )
5-2. Troubleshooting By Signal Substitution ------------------------------ ( 18 )
5-3. Troubleshooting By Signal Tracing ----------------------------------- ( 18 )
5-4. Amplifier Overload Characteristics ------------------------------------ ( 19 )
5-5. Amplifier Performance Evaluation Using Square Waves ------- ( 19 )
5-6. Testing Speakers And Impedance Networks ----------------------- ( 22 )
5-7. Digital Frequency Selection --------------------------------------------- ( 23 )
5-8. Additional Applications --------------------------------------------- ( 23 )
1. PRODUCT DESCRIPTION

1-1. Introduction
This instrument is the Most Versatile Signal Source used as FUNCTION
GENERATOR, SWEEP GENERATOR, PULSE GENERATOR and a FREQUENCY
COUNTER, offering a wide range of applications in both analog and digital electro-
nics such as engineering, manufacturing, servicing, education and hobbyist fields.
VCF(voltage controlled frequency) produces precision sine, square and triangle
waves over the 0.05 Hz to 5 MHz for sub-audible, audio, ultrasonic and RF
applications. A continuously variable DC offset allows the output to be injected
directly into circuits at the correct bias level.
Variable symmetry of the output waveforms converts the instrument to a pulse
generator capable of generating rectangular waves or pulses, ramp or sawtooth
waves and skewed sine waves of variable duty cycle. The sweep generator offers
linear sweep with variable sweep rate and sweep width up to 100:1 frequency
change. The frequency response of any active or passive device up to 5 MHz can
be determined.
1-2. Technical Specifications
OUTPUT CHARACTERISTICS
Waveforms : Sine, Square, Triangle, Ramp, Pulse, Sawtooth,
TTL/CMOS Leveled Square, DC
Frequency Range : 0.05 Hz to 5 MHz in 7 Range(1,10,100,1K,10K,100K,1M)
Frequency Accuracy : ±5% (1,10,100,1K,10K,100K,1MHz Range ) (Full Scale)
Output Level : 20 Vp-p in open circuit, 10 Vp-p into 50 ΩLoad
Output Impedance : 50 Ω±5%
Attenuator : 20 dB fixed and continuously variable
WAVEFORM CHARACTERISTICS
Sine wave -Flatness : ±2.5V to 5 MHz
-Distortion : Less than 1% at 0.5 Hz to 100 KHz
Square wave -Rise and Fall Time : Less than 25 nS
Triangle wave -Linearity : More than 99% at 0.2 Hz to 100 KHz
TTL Output -Rise and Fall time : Less than 25 nS
-Output Level : TTL Level(H 2.4V, L 0.4V)
CMOS Output -Rise and Fall Time : Less than 150 nS(Max. Out)
(DC – to 2MHz) -Output Level : 4V to 15V ±1V, Variable
DUTY RATIO : 1:1 to 10 : 1

SWEEP FUNCTION CHARACTERISTICS
Mode : Linear
Width : Variable from 1 : 1 to 100 : 1
Rate : 0.5 Hz to 50 Hz (20 mS to 2 S)
External VCF Input : Input Voltage : 0 to 10 V
Input Impedance : Approx. 10 KΩ
FREQUENCY COUNTER CHARACTERISTICS
Display : 6 digit green LED, Gate time, MHz, KHz, Hz, mHz.
Frequency Range : 500 mHz to 50 MHz With Auto Range.
Accuracy : ±Time base Error ±1 count
Time base : 10 MHz
Input Sensitivity : 100 mVrms
Max. Input Voltage : 250 Vp-p
DIMENSION AND WEIGHT
Dimension : 255(W)x 255(D) x90(H)mm
Weight : Approx. 2.0Kg
1-3. Equipment Ratings
Input Voltage Fuse Power Max.
103 󰾝 126V AC(50/60Hz) F 0.5A 250V 15W
206 󰾝 252V AC(50/60Hz) F 0.25A 250V 15W
 Operating Environment
TEMPERATURE : 0 °C to + 40 °C
HUMIDITY :up to 85% to 40°C without temperature extremes
causing condensation within the instrument.
 Storage Environment
TEMPERATURE : -20°C to +70°C
HUMIDITY : below 85% RH
 Insulation Category II : Portable equipment of local level.
 Pollution Degree : 2
 Protection to IEC 529: Ordinary

1-4. Supplied Accessories
 User’s Manual ---------------------------------------------------------------------------- 1
 BNC Cable ------------------------------------------------------------------------------ 1
 Power Cord ------------------------------------------------------------------------------ 1
 Spare Fuse ------------------------------------------------------------------------------- 1
specifications are subject to change without notice.

2. INSTALLATION
2-1. Initial Inspection
This instrument was carefully inspected both mechanically and electrically before
shipment. It should be physically free of damage. To confirm this, the instrument
should be inspected for physical damage in transit. Also, check for supplied
accessories.
2-2. Connecting AC Power
This instrument requires AC 230V/115V,50-60Hz power through 3-conductor ac
power cable to be fit into three-contact electrical outlet to secure grounding.
If forced to use 2-conductor cable, use ground terminal in rear panel for grounding
instrument.
CAUTION
THIS INSTRUMENT IS SET TO AC 230V. BEFORE POWERING ON THIS
INSTRUMENT, MAKE SURE THE VOLTAGE OF THE POWER SOURCE IS AC
230V. IN CASE OF AC115V, SWITCH SHOULD BE SELECTED DOWN TO 115V
POSITION.
2-3. Cooling And Ventilation
No special cooling and ventilation is required. However, the instrument should be
operated where the ambient temperature is maintained.
2-4. Position
This instrument is built as a bench-type instrument with rubber feet and tilt stand in
place. Stand-up angle can be adjusted by rotating angle of carrying handle.
2-5. WARMING-UP
Allow more than 20 minutes for the unit to warm up so that it is stabilized and ready
for use.

3. OPERATION
3-1. Controls, indicators and connectors
FIG 1. FRONT PANEL OPERATOR’S CONTROLS
LED DISPLAY. Displays Internal Or External
Frequency.
INTERNAL/EXTERNAL SWITCH. PUSH IN : External Frequency
Counter.
PUSH OUT: Internal Frequency
Counter.
RANGE SWITCHES. Frequency Range Selector.
FUNCTION SWITCHES. Select Sine wave, Triangle Wave Or
Square Wave Output.
ATTENUATOR. Selects Output Level By -20 dB.
GATE TIME INDICATOR. Gate Time Is Selected Automatically By
Input Signal.
FREQUENCY DIAL. Controls Output Frequency In Selected
Range.
MHz, KHz , Hz, mHz INDICATOR. Indicates Unit Of Frequency.
EXTERNAL COUNTER INPUT BNC. Used As An External Frequency
Counter.
SWEEP RATE CONTROL. On-Off Switch For Internal Sweep
Generator, Adjusts Sweep Rate Of
Internal Sweep Generator.
SWEEP WIDTH CONTROL. Pullout And Adjusts Magnitude Of

Sweep.
VCF INPUT BNC. Voltage Controlled Frequency Input
Permits External Sweep.
Frequency Control Sweep Rate Control
Should Be Off When Applying External
Voltage At This BNC.
SYMMETRY CONTROL. Adjust Symmetry Of Output
Waveform 1:1 to 10:1 With Push/Pull
Switch On.
TTL/CMOS CONTROL. Selects TTL Or CMOS Mode
Pull-out : CMOS Level Control, Push-
In: TTL Level.
TTL/CMOS OUTPUT BNC. TTL/CMOS Level Output.
DC OFFSET CONTROLS. Adds Positive Or Negative DC
Component To Output Signal.
MAIN OUTPUT BNC. Impedance 50 Ohm.
AMPLITUDE CONTROL. Adjusts Output Level From 0 TO -20 dB.
TILT STAND. Pull Out To Adjust Tilt.
POWER SWITCH. Push type switch. turning on the power
when pressed.
FIG 2. REAR PANEL
FUSE HOLDER. Replacing fuse with unscrewing
AC INLET. For connection of the supplied AC
power
115V 230V
115V
230V
SN :
VOLTAGE POWER MAX
0.5AF
0.25AF
FUSE 10W
10W
22
21

3-2. Operating instruction
This instrument is capable of generating a wide variety of waveforms and counting an
external frequency with high resolution of 6 digits LED. The most benefit and satisfaction
can be gained from the instrument by fully understanding its capabilities and versatility and
becoming familiar with operation procedure. One of the best ways to initially gain this
familiarization is to connect the generator to an oscilloscope. Observe the waveforms and
notice the effects of the various controls on the waveforms. Use this manual as a reference
until becoming accustomed to operating procedures.
3-3. Use As Function Generator.
3-3-1. Procedure
A. Connect AC power cord into receptacle on rear panel and plug into AC inlet.
B. To turn on equipment, push power on-off switch on.
C. To make sure that the output is symmetrical and unaffected by the sweep
generator, set the following controls as below.
CONTROLS POSITION
Sweep width OFF(push)
Symmetry OFF(push)
DC offset OFF(push)
Attenuator RELEASE(button out)
Counter INTERNAL(button out)
D. To select the desired frequency, set the Range Switch and FREQ. dial as
follows; The output frequency equals the FREQ. dial setting multiplied by the
Range Switch setting.
For example, a FREQ. dial setting of 0.6 and a Range switch setting of 10K
produces a 6 KHz output(.6x10 = 6K). A FREQ. dial setting of 5.0 and a Range
switch setting of 1M produces 5 MHz output(5.0x1M = 5M).
E. And also it can display the desired frequency by 4 digit LED display.
F. Select sine, square, or triangle wave output by pressing the corresponding
FUNCTION button. FIG 3. illustrates the output waveforms and their phase
relationships.
G. Connect a cable from the 50ΩBNC to the point where it is desired to inject the signal.
H. Adjust the 50Ωoutput to the desired amplitude with the AMPLITUDE control.

FIG. 3 OUTPUT WAVEFORMS AND PHASE RELATIONSHIPS
I. A positive or negative DC component can be added to the signal at the 50ΩBNC
by use of the DC OFFSET control, as required by the circuit into which the signal
is being injected.
J. A fixed amplitude TTL square wave is available at the TTL OUT BNC on the front
panel. This signal is unaffected by the AMPLITUDE, ATTENUATOR or DC
OFFSET. TTL output is a square wave for use in digital circuits, even though
FUNCTION SWITCH is on sine or triangle wave.
3-3-2. Considerations CAUTION
KNOWLEDGE OF THE FOLLOWING FACTORS IS ESSENTIAL FOR PROPER
OPERATION OF THE INSTRUMENT:
A. The DC offset control can provide over ±10 volts open-circuited, or ±5 volts
into 50Ωload. Remember that the combined signal swing plus DC offset is also
limited to ±10 V open-circuited, or ±5 V into 50Ω. Clipping occurs slightly next
page these levels. FIG 4. illustrates the various operating conditions encountered
when using DC offset. If the desired output signal is large or if a large DC offset is
used, an oscilloscope should be used to make sure that the desired combination is
obtained without clipping. Keeping the Amplitude control in the lower half of its
adjustment range reduces the probability of clipping.
B. To set the DC offset to zero or a specific DC voltage, depress the Function
Switches slightly so that all switches are released(all buttons out). This removes
signal from the output and leaves the DC only. Measure the DC output on an
oscilloscope or DC voltmeter and adjust the DC offset control for the desired value.
Trian
g
le 0V
Square 0V
TTL Pulse 0V
Sine 0V

C. It is easier to accurately set the FREQ. dial if settings between 0.5 and 5.0 are
used. Since the dial rotation overlaps ranges, it is not usually necessary to use
readings below 1. Just change to a lower range and use a higher dial setting.
FIG 4. USE OF DC OFFSET CONTROL
D. The main output BNC is labeled 50Ω. This means that the source impedance is
50Ω, but the output may be fed into any circuit impedance. However, the output
level varies in proportion to the terminating impedance. If it is desired to maintain a
constant output level while injecting signal into various circuits with various
impedance, a constant terminating impedance is necessary. When the generator
output is connected to a coaxial connector on the equipment under test, it usually
moderate to high impedance. A reasonably constant terminating
impedance may be maintained while injecting signal into moderate and high
impedance circuits(500Ωand up)by adding a coaxial tee in the output cable and
connecting a 50Ωtermination to one leg. Remove the 50Ωtermination when
injecting into a 50Ωcircuit. Also keep DC injection point, the DC offset should be
set to match the circuit voltage, or blocking capacitor may be required to avoid DC
loading with 50Ω.
E. When using the higher output frequencies and when using the square wave
output, terminate the cable in 50Ωto minimize ringing. Keep the cables as short as
possible.
F. To set output amplitude to a specific level, measure peak to peak amplitude on
an oscilloscope.
+5V
0V
-5V
+5V
0V
-5V
Positive
DC Offset Negative DC Offset
Positive
DC Offset Negative DC Offset
A. Zero DC Offset
With Maximum Signal
B. Offset Limits
Without /Clipping
C. Excessive Offset
All Example
Output Terminated In 50Ω
+5V
0V
-5V

3-4. Use As Pulse Generator
In a symmetrical square wave, sine wave, or triangle wave, the positive and
negative transitions are of equal time duration, or 1:1 ratio. This is the condition
when the SYMMETRY control off. When the SYMMETRY control is pulled and
rotated, the positive transition can be stretched in relation to the negative transition,
up to at least, 10:1 ratio. Square waves can be stretched into rectangular waves or
pulses, triangle waves can be stretched into distorted wave shape called a skewed
sine wave. FIG 5. illustrates the types of waveforms possible and includes a
summary of control settings used to obtain the desired waveform.
3-4-1. Procedure
A. Setup generator as described for function generator operation. Display the
output of generator on an oscilloscope.
B. Select the desired type of waveform with the Function Switches. Press the
square wave button for pulses, triangle button for ramp waves or sine wave button
for skewed sine waves.
FIG 5. PULSE, RAMP, AND SKEWED SINE WAVE GENERATION
C. If both a specific pulse width and repetition rate (specific rise time and fall time
for ramp wave), :are required, The waveform may be obtained as follows:
a. Adjust the shorter duration portion of the waveform(pulse width for pulse, fall
time for ramp waves)with the frequency controls FREQ. dial and RANGE switch.
b. Adjust the longer duration portion of the waveform(rest time for pulses, rise time
Adjust Period Of Shorter
Duration With Fre
q
. Controls
Pulse
(Square)
Ramp
(Triangle)
Skewed
(Sine)

for ramp waves)with the SYMMETRY control.
D. If a specific pulse width (specific fall time for ramp wave)is not critical, but a
specific repetition rate is required, the desired waveform may be obtained as
follows;
a. Observe the oscilloscope and adjust the SYMMETRY control to obtain the
approximate desired pulse width vs. rest time ratio(rise time vs. fall time ratio for
ramp waves).
b. Adjust the repetition rate with the frequency controls FREQ. dial and RANGE
switch. the frequency controls affect both the pulse width and repetition rate.
3-4-2. Considerations
A. When generating ramp waves or skewed sine waves, it may be easier to
measure the time periods on oscilloscope using the square wave mode, then switch
to the desired operating mode.
B. For ease and accuracy in measurement, use a higher sweep speed on the
oscilloscope to expand the pulse width for measurement, then reduce sweep speed
to measure the repetition rate.
C. Repetition rate may be expressed as a frequency or time period. Measure the
repetition rate as a time period on oscilloscope and convert to frequency if required.
The repetition rate includes the full cycle, both the pulse width and rest time for
pulses, the rise time and fall time for ramp waves.
D. Repetition rate can be measured accurately and easily as a frequency or time
period with a frequency counter.
E. Pulse width also can be measured on a frequency counter, but only with the
SYMMETRY control set off before the pulse waveform is “stretched”. Pulse width
equals one-half the time period of the square wave. If the counter is not equipped
for period measurement, calculate the frequency, which is equivalent to the desired
pulse width, and measure the frequency of the waveform.
1
DESIRED PULSE WIDTH x 2
3-5. TTL/CMOS OUTPUT
TTL/CMOS output is specifically designed for compatibility with TTL/CMOS digital
logic circuits. Set-up time is considerably reduced because the fixed logic levels
and polarity are ready for direct injection into TTL/CMOS circuits. there is a need for
protection from accidental Application of too high amplitude or incorrect DC offset
which might damage semiconductors. Another advantage is the extremely fast rise
time and fall time of signal. To use the TTL/CMOS output, connect a cable from
TTL/CMOS BNC on the Front panel to the point at which it is desired to inject the
signal. TL/CMOS output may be used in several modes of operation. Some
examples follow.
A. Using the square wave generator or pulse generator modes, clock pulses can be
generated for testing, troubleshooting or circuit analysis. The instrument could even
be used as a substitute master clock generator as TTL/CMOS circuits can be driven
from the TTL/CMOS BNC.
B. The CMOS Level Control potentiometer (pull out position) provides CMOS level
output from 5V to 15V Variable and Continuously. For TTL/CMOS output level,
Rotate the potentiometer switch and Observe the TTL or CMOS output : Push-in is
TTL, Pull-out is CMOS.
DESIRED FREQUENCY =

3-6. Use As FM Signal Generator
3-6-1. Procedure
A. Set up equipment as described for function generator operation. Use the
frequency and amplitude controls to set the carrier to the desired frequency and
amplitude.
B. Connect an AC modulating signal with no DC component to the VCF IN BNC on
the front panel of generator.
C. Adjust amplitude of the AC modulating signal for the desired frequency deviation.
3-6-2. Considerations
A. The approximate frequency deviation for a given VCF IN signal can be
determined as follows,
The 0.1 V change at the VCF IN BNC produces a frequency change of 1% of the
highest frequency obtainable on a given range. For example, the highest frequency
obtainable on the 100 K range is 500 KHz. One percent of 500 KHz equals 5 KHz.
Therefore, 0.1 V change at the VCF IN BNC will deviate the output frequency 5
KHz on the 100K range. Following table summarizes the frequency deviation
versus VCF IN voltage for all ranges.
HIGHEST FREQ. FREQ. DEVIATION FOR EACH
RANGE OBTAINABLE(Hz) 0.1 VOLT VCF IN CHANGE(Hz)
1 5 0.05
10 50 0.5
100 500 5
1K 5K 50
10K 50K 500
100K 500K 5K
1M 5M 50K
Frequency deviation versus VCF IN voltage.
B. For an example, it is assumed that we wish to generate a 455 KHz signal with
FM deviation of ±15 KHz (30 KHz swing). 1M range will be used to obtain the 455
KHz carrier with the FREQ. dial set to 0.455. The highest frequency obtainable on
the 1M range is 5 MHz. One percent of 5 MHz is 50 KHz. Our requirement of 30
KHz deviation is 0.6 times less than 50 KHz deviation produced by a 0.1 volt VCF
IN swing, thus we will use 0.6 times as much peak-to-peak voltage swing, or
0.06 V.
STATED ANOTHER WAY: SUBSTITUTING THIS
EXAMPLE:
desired deviation 30 KHz
1% deviation 50 KHz
x0.1 V = re
q
uired VCF IN si
g
nal x 0.1 = 0.06 x 0.1V = 0.06V

C. Remember that the value of VCF IN signal is the peak to peak amplitude.
3-7. External Control Of VCF
Within a given range, the FREQ. dial setting normally controls the output
frequency of generator. However, applying voltage at the VCF IN BNC on the front
panel also may control it. There are three basic possible modes of external VCF
control as detailed below,
A. Applying an AC voltage produces FM modulation(previously described in “Use
as FM Signal Generator” paragraph)
B. Applying a specific fixed DC voltage will produce a specific output frequency
described in following “Programmed Frequency Selection”paragraph
C. Applying a ramp voltage(or other type waveform if desired)provides externally
controlled sweep generator operation(described in following “Use as Externally
Controlled Sweep Generator” paragraph)
The following consideration apply to all modes of operation involving external
control of the VCF(voltage controlled frequency)
A. The output frequency of generator is determined by the voltage applied to the
VCF. First of all, this voltage is established by the setting of the FREQ. dial. Any
voltage input drives the VCF TO A HIGHER FREQUENCY. However. The VCF can
never be driven beyond its range limits (the highest and lowest frequencies that can
be attained with the dial on a given range.)
B. With the FREQ. dial set at minimum(0.05) and 0 volts at the VCF in BNC, the
generator output frequency is at the lower limit of the selected range. Increasing the
voltage to + 10 volts drives the generator frequency to the upper limit of the range.
Between 0 and + 10 Volts, the generator output frequency is proportional to the
VCF IN voltage. The VCF IN voltage can be correlated to equivalent dial settings as
given in Table below.
VCF voltage Equivalent dial Setting
0 0.05
1 .5
2 1.0
3 1.5
4 2.0
5 2.5
6 3.0
7 3.5
8 4.0
9 4.5
10 5.0

Correlation between VCF IN voltage and equivalent dial setting(dial set to 0.05)
C. The FREQ. dial is usually set to 0.05 when using external VCF control. This
reduces the dialed VCF voltage to zero and allows the external VCF voltage to
exercise complete control. It also reduces the effects of dial setting inaccuracy.
D. If the summed dial setting and VCF IN voltage exceeds +10 volts, oscillation
ceases and no output is produced. If the swing of the VCF IN signal is too great,
oscillation will cease each time the instantaneous voltage reaches the limit.
3-8. Programmed Frequency Selection
A specific output frequency can be selected each time a specific VCF input voltage
is applied(assuming a common dial setting). Such operation may be advantageous
where there is a requirement to return to a specific frequency periodically.
Eliminating the need for frequency measurement reduces set-up time and precision
tuning each time frequency is needed. Just set the dial against its lower stop and
turn on the external VCF voltage. Using multiple DC voltage values, which may be
selected by a switch or electronic switching circuits, may program a set of two or
more specific frequencies. This type of operation would be desirable in production
testing where signals at several specific frequencies are required for various tests.
FSK(frequency shift keying)signals also may be generated in this manner. To
maintain the original accuracy each time the operation is repeated, the FREQ. dial
must be accurately set to the same position. Probably the easiest way to assure
this common dial setting is to set it against its lower stop(0.05). Additional
information on programmed frequency selection is given in APPLICATIONS chapter
of this manual.
3-9. Use As Sweep Generator
3-9-1. Procedure
A. Set up equipment as for function generator operation.
B. Select the highest frequency to be swept with RANGE switch and the
lowest frequency to be swept with FREQ. dial.
C. Adjust amount of sweep with the sweep rate control.
D. Adjust repetition rate of sweep with the sweep rate control.
3-9-2. Considerations
0.05 or low FREQ. dial setting is recommended for most sweep generator operation.
The dial setting determines the lowest frequency of generator. The sweep
generator will sweep upward from that point. However, it will sweep upward only to
the range limit(highest frequency to which the dial can tune on the selected range).
Therefore, a low dial setting is required to obtain a sweep covering a wide
frequency range. The 0.05 setting must be used to obtain the maximum sweep
width of 100:1(highest frequency sweep is 100 times that of lowest frequency
swept).If a high dial setting and high SWEEP WIDTH setting are used
simultaneously, the generator will sweep to the range limit and ceases operation for
a portion of the sweep cycle, effectively clipping the sweep. Of course, if only a
small frequency band is to be swept, a low dial setting is not important. In fact, it

may be easier to set to the desired frequencies if the dial setting is 0.5 or higher.
3-10. Use As Externally Controlled Sweep Generator
A ramp voltage, or any other type waveform desired, can be applied for externally
controlled sweep generator operation. 0 to 10 volt swing will sweep frequencies
over a 100:1 ratio(with dial set to 0.05) Set up the instrument as described for
internally controlled sweep generator operation, except turn the SWEEP WIDTH
control to OFF. Apply the sweep voltage with no DC component at the VCF Input
BNC. Set the FREQ. dial to the highest frequency to be swept and apply a
negative-going ramp voltage.
3-11. Use As External Frequency Counter
3-11-1. USE AS EXTERNAL FREQUENCY COUNTER
A. EXTERNAL AND INTERNAL COUNTER SELECTION
This instrument can be used as a counter by Push-in of INT/EXT selection switch.
B. EXT COUNT IN BNC accepts external frequency input.
C. COUNTER DISPLAY
Input frequency is displayed with high resolution on a 6 digit LED display.
D. mHz, Hz, KHz, MHz INDICATOR
mHz, Hz, KHz, MHz indicators & decimal points display the max. 50 MHz of
external frequency.
E. PUSHED-IN FREQ.RANGE S.W X1.
F. When there is no input signal, the most current data is displayed. And when the
new signal has entered, the display will show updated data.
CAUTION
1. APPLICATION OF INPUT VOLTAGES HIGHER THAN THE LIMITS LISTED IN
THE SPECIFICATIONS SECTION MAY DAMAGE THE COUNTER. BEFORE
APPLYING ANY SIGNAL TO THE INPUTS, MAKE CERTAIN THAT IT DOES NOT
EXCEED THESE SPECIFIED MAXIMUMS.
2. FREQUENCY COUNTER GROUND POINTS ARE CONNECTED DIRECTLY TO
EARTH GROUND. ALWAYS CONNECT FREQUENCY COUNTER GROUND
ONLY TO GROUND POINTS IN THE CIRCUIT UNDER TES

4. MAINTENANCE
CAUTION
IT IS ESSENTIAL FOR SAFETY TO PROPERLY MAINTAIN AND SERVICE THIS
INSTRUMENT
WARNING
VOLTAGES WITHIN THIS INSTRUMENT ARE SUFFICIENTLY HIGH TO
ENDANGER LIFE. COVERS MUST NOT BE REMOVED EXCEPT BY PERSONS
QUALIFIED AND AUTHORIZED TO DO SO AND THESE PERSONS SHOULD
ALWAYS TAKE EXTREME CARE ONCE THE COVERS HAVE BEEN REMOVED.
4-1. Fuse replacement
 Disconnect and remove all connections from any live power source.
 Unscrew fuse holder by screw driver.
 Locate the defective fuse and remove it by gently pulling-out.
 Install a new fuse of the SAME SIZE AND RATING.
 Screwing fuse holder.
CAUTION
MAKE SURE THAT THE RATED AND SPECIFIED FUSES ARE USED FOR
REPLACEMENT.
4-2. Adjustment and calibration
It is recommendable to regularly adjust and calibrate this instrument. Qualified and
authorized personnel only should execute performance and procedures
4-3. Cleaning and decontamination
The instrument can be cleaned with a soft clean cloth to remove any oil, grease or
grime. Never use liquid solvents or detergents. If the instrument gets wet for any
reason, dry the instrument using low pressure clean air at less than 25 PSI. Use
care and caution around the window cover areas where water or air could enter into
the instrument while drying.