UNISource Corporation FG-8102 User manual
Operation Manual
FG-8102 2MHz Function Generator
FG-8103 3MHz Function Generator
FG-8105 5MHz Function Generator
FG-8110 10MHz Function Generator
UNISOURC CORPORATION
BENCHTOP INSTRUMENT
WARRANTY
Warranty service covers a period of one year fro 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 custo ers for repair after the one-year warranty period has been
expired. Provided that against any failure resulted fro the user’s negligence,
natural disaster or accident, we charge you for repairs regardless of the warranty
period.
For ore professional repair service, be sure to contact our service center or sales
outlet.
Introduction
Thank you for purchasing our product.Electronic easuring instru ents
produced by us are high technology products ade under strict quality control. We
guarantee their exceptional precision and ut ost reliability. For proper use of the
product, please read this operation anual carefully.
Note
1. To fully aintain the precision and reliability of the product use it within the range
of standard setting( te perature 10 °C~35 °C, hu idity 45%~85%)
2. After turning of power, please allow a pre-heating period of as long as so e 30
inutes before use.
3. This equip ent should be used with a triple line power cord for safety.
4. For quality i prove ent the exterior design and specification of the product can
be changed without prior notice.
5. If you have further questions concerning use, please contact our service center
or sales outlet
Safety Su ary
Please take a o ent to read these operating instructions thoroughly and
co pletely before operating this instru ent. Pay particular attention to WARNINGS
used for conditions and actions that pose hazard to the user and CAUTIONS used
for conditions and actions that ay da age the instru ent.
Always to inspect the instru ent and other accessories for any sign of da age
or abnor ality before every use.
Never ground yourself and keep your body isolated fro ground.
Never touch exposed wiring, connections or any live circuit conductors.
Do not install substitute parts or perfor any unauthorized odification to the
instru ent.
Use caution when working above 60V DC or 30V AC r s. Such voltages pose
a shock hazard.
Re e ber that line voltage is present on so e power input circuit points such
as on-off switches, fuse, power transfor ers, etc., even when the equip ent is
turn off.
Also, re e ber that high voltage ay appear at unexpected points in
defective equip ent.
Safety Symbols
1. Protective earth (ground)
To identify any ter inal which is intended for connection to
An exte al conductor for protection against electric shock
In case of a fault, or the ter inal of a protective earth
(ground) electrode.
2. Functional earth terminal on the rear panel.
3 “IN” position of a bi-stable push control
To associate the “IN” position of a bi-stable push control
With the corresponding function.
4. “OUT” position of a bi-stable push control
To associate the “OUT” position of a bi-stable push control
With the corresponding function.
5. Alternation current
To indicate on the rating plate that the equip ent is
Suitable for alte ating current only to identify relevant
ter inals.
6. Caution, risk of danger
7. Caution, risk of electric shock
CONT NTS
1. PRODUCT D SCRIPTION
1-1. Introduction -----------------------------------------------------------------
( 6 )
1-2. Technical Specifications -------------------------------------------------
( 6 )
1-3. Equip ent Ratings --------------------------------------------------------
( 8 )
1-4. Supplied Accessories ----------------------------------------------------
( 8 )
2. INSTALLATION
2-1. Initial Inspection -----------------------------------------------------------
( 9 )
2-2. Connecting Ac Power ----------------------------------------------------
( 9 )
2-3. Cooling And Ventilation --------------------------------------------------
( 9 )
2-4. Position ----------------------------------------------------------------------
( 9 )
2-5. War ing-Up ----------------------------------------------------------------
( 9 )
3. OP RATION
3-1. Controls, indicators and connectors ----------------------------------
( 10 )
3-2 2. Operating instruction --------------------------------------------------
( 13 )
3-3. Use As Function Generator ---------------------------------------------
( 13 )
3-4. Use As Pulse Generator -------------------------------------------------
( 16 )
3-5-1. TTL/CMOS Output -----------------------------------------------------
( 18 )
3-5-2. TTL/SYNC Output -----------------------------------------------------
( 19 )
3-6. Use As FM Signal Generator -------------------------------------------
( 19 )
3-7. External Control Of VCF -------------------------------------------------
( 21 )
3-8. Progra ed Frequency Selection ------------------------------------
( 22 )
3-9. Use As Sweep Generator -----------------------------------------------
( 22 )
3-10. Use As Externally Controlled Sweep Generator -----------------
( 23 )
3-11. Use As External Frequency Counter --------------------------------
( 23 )
4. MAINT NANC
4-1. Fuse Replace ent --------------------------------------------------------
( 25 )
4-2. Adjust ent And Calibration ---------------------------------------------
( 25 )
4-3. Cleaning and deconta ination -----------------------------------------
( 25 )
5. OTH RS
5-1. Introduction -----------------------------------------------------------------
( 25 )
5-2. Troubleshooting By Signal Substitution ------------------------------
( 26 )
5-3. Troubleshooting By Signal Tracing -----------------------------------
( 26 )
5-4. A plifier Overload Characteristics ------------------------------------
( 27 )
5-5. A plifier Perfor ance Evaluation Using Square Waves --------
( 28 )
5-6. Testing Speakers And I pedance Networks -----------------------
( 31 )
5-7. Digital Frequency Selection ---------------------------------------------
( 32 )
5-8. Additional Applications ---------------------------------------------------
( 32 )
1. PRODUCT D SCRIPTION
1.1. Introduction
This instru ent 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
electronics such as engineering, anufacturing, servicing, education and hobbyist
fields.
VCF(voltage controlled frequency) produces precision sine, square and triangle
waves over the 0.02 Hz to 10 MHz (FG-8102; 0.02Hz to 2MHz, FG-8103: 0.03Hz
to 3MHz, FG-8105; 0.05Hz to 5MHz, FG-8110; 0.1Hz to 10MHz) 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 sy etry of the output wavefor s converts the instru ent to a pulse
generator capable of generating rectangular waves or pulses, ra p 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 Maxi u
frequency of each odel can be deter ined.
1-2. Technical Specifications
OUTPUT CHARACTERISTICS
Wavefor s : Sine, Square, Triangle, Skewed Sine , Pulse , Ra p
Sawtooth, TTL Leveled Square, DC
CMOS Leveled Square(FG-8102, FG-8103 only)
Frequency Range : In 7 Range(1, 10, 100, 1K, 10K, 100K,1M)
FG-8102 ; 0.02 Hz to 2 MHz
FG-8103 ; 0.03 Hz to 3 MHz
FG-8105 ; 0.05 Hz to 5 MHz
FG-8110 ; 0.1 Hz to 10 MHz
Frequency Drift Accuracy: ±2% ( 1, 10 , 100 , 1K , 10K , 100K ,1M Range )
Output Level : 20 Vpp in open circuit, 10 Vpp into 50 Ω Load
Output I pedance : 50 Ω ±5%
Attenuator : 20 dB fixed and continuously variable
WAVEFORM CHARACTERISTICS
Sine wave -Flatness : ± 3dB to 2 MHz(8102), 3 MHz(8103),
5MHz(8105), 10MHz(8110)
-Distortion : Less than 1% at 0.2 Hz to 100 KHz
Square wave -Rise and Fall Ti e : Less than 120 nS
Triangle wave -Linearity : More than 99% at 0.2 Hz to 100 KHz
TTL Output -Rise and Fall ti e : Less than 25 nS
-Output Level : TTL Level(H 2.4V, L 0.4V)
CMOS Output -Rise and Fall Time : Less than 160 nS(Max. Out)
(8203, 8205 only)-Output Level : 4V to 15V ± 2V, Variable
DUTY RATIO : 1:1 to 10 : 1
SWEEP FUNCTION CHARACTERISTICS
Mode : Linear
Width : Variable fro 1 : 1 to 100 : 1
Rate : 0.5 Hz to 50 Hz (20 S to 2 S)
External VCF Input :
Input Voltage : 0 to 10 V
Input I pedance : Approx. 1KΩ
FREQUENCY COUNTER CHARACTERISTICS
Display :
8102/8103 : 6 digit green L D, Gate time, MHz, KHz, Hz, mHz.
8105/8110 : 7 digit green L D, Gate time, MHz, KHz, Hz, mHz.
Frequency Range :
8102/8103 : 200 mHz to 50 MHz With Auto Range.
8105/8110 : 200 mHz to 100 MHz With Auto Range.
Accuracy : ±Ti e base Error ± 1 count
Ti e base : 10 MHz Crystal, ±20pp
Input Sensitivity : 100 Vr s
Max. Input Voltage : 250 Vpp
DIMENSION AND WEIGHT
Di ension : 240(W)x 270(D) x90(H)
Weight : Approx. 2.0Kg(8102,8103), 3.0kg(8105, 8110)
1-3. quipment Ratings
Power & Fuse Ratings
Input Voltage Fuse Power Max.
115VAC +/-10%, 50/60Hz F 0.5A 250V 15W
230VAC +/-10% , 50/60Hz F 0.2A 250V (8102/8103)
F 0.25A 250V (8105/8110) 15W
NOT : AC Power is preset to 115V or 230V in factory according to the request
of customer. AC Power can be selected inside of unit.
Operating Environ ent
TEMPERATURE : 0 °C to + 40 °C (Accuracy Specified at 23°C ± 5 °C)
HUMIDITY :up to 85% to 40°C without te perature extre es
causing condensation within the instru ent.
Storage Environ ent
TEMPERATURE : -20°C to +70°C
HUMIDITY : below 85% RH
Overvoltage Category : CAT II,
Perfor ed on circuits directly connected to the low voltage installation.
Insulation Category II: Portable equip ent 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 instru ent was carefully inspected both echanically and electrically before
ship ent. It should be physically free of da age. To confir this, the instru ent
should be inspected for physical da age in transit. Also, check for supplied
accessories are present and correct.
2-2. Connecting AC Power
CAUTION
AC POW R OF THIS INSTRUM NT IS PR S T TO 115V OR 230V IN FACTORY
ACCORDING TO TH R QU ST OF CUSTOM R. B FOR POW RING ON
THIS INSTRUM NT, CH CK AND MAK SUR TH VOLTAG OF TH
POW R SOURC IS SAM WITH TH MARKING OF UNIT.
This instru ent requires 230V AC or 115V AC (50-60 Hz) power socket with
protective earth contact (PE-contact). If is available only a power socket without
PE-contact (so a 2-conductor ac power) then a power socket with PE-contact ust
be installed before or the appliance should be provided with a PE-screw-ter inal
which is not soluble by hand and not soluble before 2-conductor power lines.
2-3. Cooling and Ventilation
No special cooling and ventilation is required. However, the instru ent should be
operated where the a bient te perature is aintained.
2-4. Position
This instru ent is built as a bench-type instru ent 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 ore than 30 inutes for the unit to war up so that it is stabilized and
ready for use.
3. OP RATION
3-1. Controls, indicators and connectors
FIG 1-1. FRONT PANEL OPERATOR’S CONTROLS(8102,8103)
FIG 1-2. FRONT PANEL OPERATOR’S CONTROLS(8105,8110)
7 141 1311 6 8 912
20 2 173 184 16 5 15 19
10
21
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 Ti e Is Selected Auto atically By
Input Signal.
FREQUENCY DIAL.(Coarse,Fine) Controls Output Frequency in Selected
Range.
MHz, KHz , Hz, Hz 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
Per its External Sweep.
Frequency Control Sweep Rate Control
Should Be Off When Applying External
Voltage At This BNC.
SYMMETRY CONTROL. Adjust Sy etry Of Output Wavefor
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
Co ponent to Output Signal.
MAIN OUTPUT BNC. I pedance 50 Oh .
AMPLITUDE CONTROL. Adjusts Output Level fro 0 to 20 dB.
TILT STAND. Pull Out to Adjust Tilt.
POWER SWITCH. Push type switch. turning on the power
when pressed.
LOW PASS FILTER
FIG 2-1. REAR PANEL(8102,8103)
FIG 2-2. REAR PANEL(8105,8110)
AC INLET For connection of the supplied AC power
Voltage Selector Switch For selecting AC Input Voltage
FUSE HOLDER. Replacing fuse with unscrewing.
Ground Ter inal.
3-2. Operating instruction
This instru ent is capable of generating a wide variety of wavefor s and counting
Made in Korea
POWER MAX
230V ~
115V ~
VOLTAGE
S/N :
0.2A F
0.5A F
FUSE
10W
10W
POWER MAX
S/N :
VOLTAGE
230V ~
115V ~ 0.5A F
0.2A F
FUSE
20W
20W
an external frequency with high resolution of 6 digits L D for 8102/8103(7digits
L D for 8105/8110). The ost benefit and satisfaction can be gained fro the
instru ent by fully understanding its capabilities and versatility and beco ing
fa iliar with operation procedure. One of the best ways to initially gain this
fa iliarization is to connect the generator to an oscilloscope. Observe the
wavefor s and notice the effects of the various controls on the wavefor s. Use
this anual as a reference until beco ing accusto ed to operating procedures.
3-3. Use As Function Generator.
1) Procedure
A. Connect AC power cord into receptacle on rear panel and plug into AC inlet.
B. To turn on equip ent, push power on-off switch on.
C. To ake sure that the output is sy etrical and unaffected by the sweep
generator, set the following controls as below.
CONTROLS POSITION
Sweep width OFF(push)
Sy etry 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 ultiplied by the
Range Switch setting.
For exa ple, 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 2.0 and a
Range switch setting of 1M produces 2 MHz output(2.0x1M = 2M).
E. And also it can display the desired frequency by 6 digit L D display
FG-8102/FG-8103 – 7digit L D display for FG-8105/FG-8110.
F. Select sine, square, or triangle wave output by pressing the corresponding
FUNCTION button. FIG 3. illustrates the output wavefor s and their phase
relationships.
G. Connect a cable fro the 50Ω BNC to the point where it is desired to inject
the signal.
H. Adjust the 50Ω output to the desired a plitude with the AMPLITUDE control.
FIG. 3 OUTPUT WAVEFORMS AND PHASE RELATIONSHIPS
I. A positive or negative DC co ponent can be added to the signal at the 50Ω
BNC by use of the DC OFFSET control, as required by the circuit into which
the signal is being injected.
J. A fixed a plitude 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.
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 50Ω load. Re e ber that the co bined signal swing plus DC offset is
also li ited 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 ake sure that the
TTL Pulse 0V
Triangle 0V
Sine 0V
Square
0V
desired co bination is obtained without clipping. Keeping the A plitude
control in the lower half of its adjust ent 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
re oves signal fro the output and leaves the DC only. Measure the DC
output on an oscilloscope or DC volt eter and adjust the DC offset control for
the desired value.
C. It is easier to accurately set the FREQ. dial if settings between 0.1 and
2.0(8102) – 3.0(8103), 5.0(8105), 10(8110) 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 ain output BNC is labeled 50Ω. This eans that the source i pedance
is 50Ω, but the output ay be fed into any circuit i pedance. However, the
output level varies in proportion to the ter inating i pedance. If it is desired
to aintain a constant output level while injecting signal into various circuits
with various i pedance, a constant ter inating i pedance is necessary.
When the generator output is connected to a coaxial connector on the
equip ent under test, it usually oderate to high i pedance. A reasonably
A. Zero DC Offset
with axi u signal
B. Offset li its
without Clipping
C. Excessive Offset
all exa ple
output ter inated in 50
+5V
0V
-5V
+5V
0V
-5V
+5V
0V
-5V
Positive
DC Offset
Negative
DC Offset
Positive
DC Offset
Negative
DC Offset
constant ter inating i pedance ay be aintained while injecting signal into
oderate and high i pedance circuits(500Ω and up)by adding a coaxial tee
in the output cable and connecting a 50Ω ter ination to one leg. Re ove the
50Ω ter ination when injecting into a 50Ω circuit. Also keep DC injection
point, the DC offset should be set to atch the circuit voltage, or blocking
capacitor ay be required to avoid DC loading with 50Ω.
E. When using the higher output frequencies and when using the square wave
output, ter inate the cable in 50Ω to ini ize ringing. Keep the cables as
short as possible.
F. To set output a plitude to a specific level, easure peak to peak a plitude
on an oscilloscope.
3-4. Use As Pulse Generator
In a sy etrical square wave, sine wave, or triangle wave, the positive and
negative transitions are of equal ti e 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 wavefor s possible and includes a
su ary of control settings used to obtain the desired wavefor .
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 wavefor with the Function Switches. Press the
square wave button for pulses, triangle button for ra p 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 ti e and fall
ti e for ra p wave), :are required, The wavefor ay be obtained as
follows:
a. Adjust the shorter duration portion of the wavefor (pulse width for pulse,
fall ti e for ra p waves)with the frequency controls FREQ. dial and
RANGE switch.
b. Adjust the longer duration portion of the wavefor (rest ti e for pulses,
rise ti e for ra p waves)with the SYMMETRY control.
D. If a specific pulse width (specific fall ti e for ra p wave)is not critical, but a
specific repetition rate is required, the desired wavefor ay be obtained as
follows;
a. Observe the oscilloscope and adjust the SYMMETRY control to obtain
the approxi ate desired pulse width vs. rest ti e ratio(rise ti e vs. fall
ti e ratio for ra p 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.
Pulse
(Square)
Ra p
(Triangle)
Skewed
(Sine)
TTL
SYNC
Adjust Period Of Shorter
Duration With Freq. Controls
Adjust Period Of Longer
Duration With
Sy etry Controls
2) Considerations
A. When generating ra p waves or skewed sine waves, it ay be easier to
easure the ti e periods on oscilloscope using the square wave ode, then
switch to the desired operating ode.
B. For ease and accuracy in easure ent, use a higher sweep speed on the
oscilloscope to expand the pulse width for easure ent, then reduce sweep
speed to easure the repetition rate.
C. Repetition rate ay be expressed as a frequency or ti e period. Measure
the repetition rate as a ti e period on oscilloscope and convert to frequency
if required. The repetition rate includes the full cycle, both the pulse width
and rest ti e for pulses, the rise ti e and fall ti e for ra p waves.
D. Repetition rate can be easured accurately and easily as a frequency or
ti e period with a frequency counter.
E. Pulse width also can be easured on a frequency counter, but only with the
SYMMETRY control set off before the pulse wavefor is “stretched”. Pulse
width equals one-half the ti e period of the square wave. If the counter is
not equipped for period easure ent, calculate the frequency, which is
equivalent to the desired pulse width, and easure the frequency of the
wavefor .
1
DESIRED PULSE WIDTH x 2
3-5-1. TTL/CMOS OUTPUT(FG-8102/FG-8103 only)
TTL/CMOS output is specifically designed for co patibility with TTL/CMOS digital
logic circuits. Set-up ti e 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 fro accidental Application of too high a plitude or incorrect DC
offset which ight da age se iconductors. Another advantage is the extre ely
fast rise ti e and fall ti e of signal. To use the TTL/CMOS output, connect a cable
fro TTL/CMOS BNC on the Front panel to the point at which it is desired to inject
the signal. TL/CMOS output ay be used in several odes of operation. So e
exa ples follow.
DESIRED FREQUENCY =
A. Using the square wave generator or pulse generator odes, clock pulses
can be generated for testing, troubleshooting or circuit analysis. The
instru ent could even be used as a substitute aster clock generator as
TTL/CMOS circuits can be driven fro the TTL/CMOS BNC.
B. The CMOS Level Control potentio eter (pull out position) provides CMOS
level output fro 5V to 15V Variable and Continuously. For TTL/CMOS
output level, Rotate the potentio eter switch and Observe the TTL or CMOS
output : Push-in is TTL, Pull-out is CMOS.
3-5-2. TTL/SYNC OUTPUT(FG-8105/FG-8110 only)
TTL/SYNC output is specifically designed for co patibility with TTL SYNC digital
logic circuits. Set-up ti e is considerably reduced because the fixed logic levels
and polarity are ready for direct injection into TTL SYNC circuits. there is a need for
protection fro accidental Application of too high a plitude or incorrect DC offset
which ight da age se iconductors. Another advantage is the extre ely fast rise
ti e and fall ti e of signal. To use the TTL SYNC output, connect a cable fro
TTL SYNC BNC on the Front panel to the point at which it is desired to inject the
signal. TTL SYNC output ay be used in several odes of operation. So e
exa ples follow.
A. Using the square wave generator or pulse generator odes, clock pulses
can be generated for testing, troubleshooting or circuit analysis. The
instru ent could even be used as a substitute aster clock generator as
TTL SYNC circuits can be driven fro the TTL SYNC BNC.
3-6. Use As FM Signal Generator
1) Procedure
A. Set up equip ent as described for function generator operation. Use the
frequency and a plitude controls to set the carrier to the desired frequency
and a plitude.
B. Connect an AC odulating signal with no DC co ponent to the VCF IN BNC
on the front panel of generator.
C. Adjust a plitude of the AC odulating signal for the desired frequency
deviation.
2) Considerations
A. The approxi ate frequency deviation for a given VCF IN signal can be
deter ined 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 exa ple(8202), the highest frequency obtainable on the 100 K
range is 200 KHz. One percent of 200 KHz equals 2 KHz. Therefore, 0.1 V
change at the VCF IN BNC will deviate the output frequency 2 KHz on the
100K range. Following table su arizes the frequency deviation versus
VCF IN voltage for all ranges.
HIGHEST FREQ.
OBTAINABLE(Hz)
FREQ. DEVIATION FOR EACH
0.1 VOLT VCF IN CHANGE(Hz)
RANGE
8102
8103
8105
8110
8102
8103
8105
8110
1 2 3 5 10 0.02 0.03 0.05 0.1
10 20 30 50 100 0.2 0.3 0.5 1
100 200 300 500 1k 2 3 5 10
1K 2k 3k 5k 10k 20 30 50 100
10K 20k 30K 50k 100k 200 300 500 1k
100K 200k
300k 300k 1M 2K 3k 5k 10k
1M 2M 3M 5M 10M 20K 30k 50k 100k
Frequency deviation versus VCF IN voltage for each model.
B. For an exa ple(8102), it is assu ed 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 2 MHz. One percent of 2 MHz is 20
KHz. Our require ent of 30 KHz deviation is 1.5 ti es greater than 20 KHz
deviation produced by a 0.1 volt VCF IN swing, thus we will use 1.5 ti es as
uch peak-to-peak voltage swing or 0.15 V.
STATED ANOTHER WAY: SUBSTITUTING THIS EXAMPLE:
desired deviation 30 KHz
1% deviation 20 KHz
C. Re e ber that the value of VCF IN signal is the peak to peak a plitude.
x0.1 V = required VCF IN signal
x 0.1 = 1.5 x 0.1V = 0.15V
This manual suits for next models
3
Table of contents
