Motech FG 700F Series User manual

Operating Manual
FG 700S/F Series
Direct Digital Synthesis
Function Generator

SAFETY PRECAUTION
SAFETY CONSIDRATIONS
The Model FG700S/F series Direct Digital Synthesis Function Generator has been designed and tested
according to EN61010-1:2001 and EN61326:1997.
SAFETY PRECAUTIONS
SAFETY NOTES
The following general safety precautions must be observed during all phases of operation, service, and
repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in
this manual violates safety standards of design, manufacture, and intended use of the instrument. The
manufacturer assumes no liability for the customer‘s failure to comply with these requirements.
BEFORE APPLYING POWER 
Verify that the product is set to match the available line voltage is installed.
SAFETY SYMBOLS
Caution, risk of electric shock
Earth (ground) terminal
Equipment protected throughout by double insulation or
reinforced insulation

Caution (refer to accompanying documents)
Equipment complies with current EU directives
Protective earth (ground) terminal
Chassis terminal
Indoor use only
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT
Because of the danger of introducing additional hazards, do not install substitute parts or perform any
unauthorized modification to the instrument. Return the instrument to a qualified dealer for service and
repair to ensure that safety features are maintained.
INSTRUMENTS WHICH APPEAR DAMAGED OR DEFECTIVE SHOULD BE MADE
INOPERATIVE AND SECURED AGAINST UNINTENDED OPERATION UNTIL THEY CAN
BE REPAIRED BY QUALIFIED SERVICE PERSONNEL.

WARRANTY INFORMATION
ONE-YEAR-LIMITED WARRANTY
MOTECH INDUSTRIES INC. (MOTECH) warrants to the original user or purchaser that the unit is
free from any defects in material or workmanship for a period of one year from the date of purchase.
If any defect is discovered within the warranty period, MOTECH will repair or replace the unit, subject
to verification of the defect or malfunction, upon delivery or prepaid shipment to MOTECH.
This warranty does not apply to defects or to physical damage resulting from abuse, neglect, accident,
improper repair, alteration, or unreasonable use of the unit, resulting in (but not limited to) cracked or
broken case or parts, or to units damaged by excessive heat. Except upon initial purchase, this
warranty does not cover finish or appearance items nor does it cover items damaged in shipment to
MOTECH for repair or calibration.
To receive service under this warranty, you must include proof of purchase, including date and place of
purchase, (a copy of your purchase receipt) or MOTECH will not be responsible for repairs or
replacement of the unit under warranty.
Any applicable implied warranties, including warranties of merchant ability and fitness for a particular
use, are hereby limited to one year from the date of purchase. Consequential or incidental damages
resulting from loss of use, or from a breach of any applicable express or implied warranties are hereby
excluded.
The warranty is not to substitute all other agreements and warranties, general or special, express or
implied, and no representative or person is authorized to assume for us any other liability in connection
with the sale or use of this MOTECH product.

Table of Content
1. Introduction................................................................................................................................... 1
1.1 General .............................................................................................................................. 1
1.2 Key Features...................................................................................................................... 1
1.3 Physical Description .......................................................................................................... 1
1.4 Specification...................................................................................................................... 3
2. Operation....................................................................................................................................... 7
2.1 Keypad and Knob Description............................................................................................ 7
2.2 Opening Screen.................................................................................................................. 8
2.3 Setting Group Name........................................................................................................... 9
2.4 Adjust Frequency............................................................................................................... 9
2.5 Select Waveform................................................................................................................ 9
2.6 Frequency Sweep............................................................................................................. 10
2.7 Output Attenuation........................................................................................................... 13
2.8 Rotary Frequency Step Setting ......................................................................................... 13
2.9 Amplitude, Offset and Square Wave Pulse Width Display ................................................ 14
2.10 Trigger/Gate..................................................................................................................... 16
2.11 Phase-Shift Keying (PSK) and Frequency-Shift Keying (FSK) Modulation...................... 16
2.12 Sub Function.................................................................................................................... 18
2.13 Notice of Operating.......................................................................................................... 22

1
1. Introduction
1.1 General
The Motech Model FG700S/F series is a high-performance direct digital synthesize (DDS) function
generator with very low noise and distortion. Combined with the DDS technology, the FG 700S/F series
can output high accuracy and stable frequency to meet your test requirement of precision and accuracy.
The build-in trigger/gate function allows you to control the waveform generation by internal or external.
Also, the PSK and FSK modulation gives you the ability to generate such waveform for experiment or
communication purpose. The FG 700F series comes with AM/FM module and frequency counter to
make the function of this product more comprehensive.
1.2 Key Features
Direct digital synthesize multi-function generator
Sine, square, triangle, pulse, DC, synchronize and ramp up/ramp down (FG 700F series) output
Ultra low noise and low distortion (down to 1Mv peak signal)
PSK and FSK modulation
Digital setting of linear or logarithm sweep function
Trigger and gate function
AM/FM module (FG 700F series)
Frequency counter (FG 700F series)
1.3 Physical Description
FG 700 Series Front Panel

2
FG 700F Series Front Panel
Rear Panel
1
Liquid
Crystal Display
2
Keypad
3
Square Wave
Pulse Width Adjustment On/Off Indicator
4
Output Offset On/Off Indicator
5
Output Amplitude Attenuation Range Indicator
6
External/Internal indicator of Trigger/Gate or PSK/FSK
7
Rotary with Push Button
8
Handle
9 Function Output BNC Connector (50output impedance)

3
10
External input
BNC Connector
for Trigger/Gate and PSK/FSK (CMOS level)
11
Amplitude Adjustment Knob
12
DC/Offset Adjustment Knob
13
Square Wave Pulse Width Adjustment Knob
14 Sync Output Connector (TTL level with 50output impedance)
15
Power Switch
16
Adjustable F
eet
17
Air
Ventilation
Holes
18
Power
-
line
Fuse Holder
19
Power
-
line
AC
Input
Socket
20
Chassis
Terminal
2
1
Protective Earth (Ground) Terminal
22
External Modulation Input (5.5Vp
Max.
)
for AM/FM Function
23
External Frequency Input (5Vrms Max. @ 50
Ω) for Frequency Counter Function
24
Internal AM/FM
Adjustment Knob
1.4 Specification
FG 708S
Output Characteristics
a. Frequency Range : Sine, Square, Pulse and Sync Output: 100mHz ~ 8MHz
Triangle : 100mHz ~ 1MHz
b. Frequency Resolution : 100mHz or 6 digits display
c. Output Impedance : 50Ω5%
d. Amplitude : 1mV to 20Vp-p (open-circuit)
0.5mV to 10Vp-p (50Ωload)
e. Amplitude Resolution : 10m[email protected]~9.99V ,1mV@10mV~99mV ,0.1mV@1mV~9.9
mV ,[email protected]mV~0.99mV (Depend on Attenuation)
f. Amplitude Accuracy : Typical 1% test at 1KHz 9Vp-p sine @ 50Ωload
g. Output Attenuation : 0, -20, -40 and -60 db
h. FUNC_OUT Self Protection : FUNC_OUT short circuit protection
Reverse voltage protection below 20Vpeak
i. DC Offset and DC Output : 10V at open-circuit, 5V at 50Ωload
j. DC Output Resolution : 10mV@±9.99V ,1mV@±99mV ,0.1mV@±9.9mV ,0.01mV@±
0.99mV (Depend on Attenuation)
k. DC Output Accuracy : 1% 5 counts (Amplitude Knob at Maximum Position)
l. Sine Wave Harmonic Distortion : DC ~ 100KHz < -55dBc typical
100KHz ~ 1MHz < -45dBc typical
1MHz ~ 8MHz < -35dBc typical
m. Spurious (non harmonic) : DC ~ 1MHz < -55dBc typical
n. Total Harmonic Distortion : DC ~ 100KHz < 0.3%
o. Square Wave : rise / fall time 15nS for 10Vp-p @ 50Ωload
overshoot < 5% of Vp for 10Vp-p @ 50Ωload
p. Pulse Generator : Frequency range : 100mHz ~ 8MHz
Amplitude : 0 ~ 10V / 0 ~ -10V / 10V
Duty cycle : 100mHz ~ 5MHz: 20% to 80%
5MHz ~ 8MHz : 40 % to 60%
q. Triangle Wave Linearity : 99% up to 100KHz
r. Sweep (Linear / Logarithmic) : Start frequency, stop frequency and sweep step
Sweep type : up, down and up-down

4
s. Sync Output : Frequency range : 100mHz ~ 8MHz
Output level : low level 0.6V @ 50Ω
high level 1V @ 50Ω
Output impedance : 50Ω

Modulation Characteristics

a. FSK : Function : Sine, Square or Triangle
Frequency range : 100mHz ~ 8MHz
Internal rate : 400Hz / 1000Hz
Source : Internal / External
b. PSK : Function : Sine, Square or Triangle
Frequency range : 100mHz ~ 8MHz
Phase setting : 0.0000 to 360.0 degree
Internal rate : 400Hz / 1000Hz
Source : Internal / External
Trigger/Gate Characteristics
a. Trigger : Source : Manual (rotary push) / External
Main frequency setting : 100mHz ~ 100KHz
b. Gate : Source : Manual (rotary push) / External
Main frequency setting : 100mHz ~ 8MHz
General Characteristics
a. Power Source : AC 115V / 230V 10%, 50Hz / 60Hz
b. Temperature : 0ºC ~ 40ºC (Operation)
-20ºC ~ 70ºC (Storage)
c. Relative Humidity : up to 80%
d. Dimension : 235mm(W)× 95mm(H)×280mm(D)
e. Weight : 3Kg
f. Accessories : AC power cord 1
Operating Manual 1
FG 710F/720F
Output Characteristics
a. Frequency Range : Sine, Square, Pulse and Sync Output: 100mHz ~ 10M/20MHz
Triangle : 100mHz ~ 1MHz
Ramp Up, Ramp Down : 100mHz ~ 20KHz
b. Frequency Resolution : 100mHz or 6 digits display
c. Output Impedance : 50Ω±5%
d. Amplitude : 1mV to 20Vp-p (open-circuit)
0.5mV to 10Vp-p (50Ωload)
e. Amplitude Resolution : 10m[email protected]~9.99V ,1mV@10mV~99mV ,0.1mV@1mV~9.9
mV ,[email protected]V~0.99mV (Depend on Attenuation)
f. Amplitude Accuracy : Typical 1% test at 1KHz 9Vp-p sine @ 50Ωload
g. Output Attenuation : 0, -20, -40 and -60 db
h. FUNC_OUT Self Protection : FUNC_OUT short circuit protection
Reverse voltage protection below 20Vpeak