Kenwood FG-272 - User Manual

©PRINTED IN J. N
FUNCTION GENERATOR
FG-272
INSTRUCTION MANUAL
KENWOOD CORPORATION
KENWOOD

Summary

Introduction to the FG-272 Function Generator

Key Features of the FG-272

Precautions for Safe Operation

Technical Specifications of the FG-272

Operators Controls and Instructions

Front Panel Controls

Details the various controls, knobs, and indicators located on the FG-272 front panel for operation.

Rear Panel Connections

Describes the connectors and features found on the rear panel, including power and input jacks.

Maintenance Procedures

Fuse Replacement

Instructions for replacing the fuse in the FG-272, including fuse types for different voltage ranges.

Changing Supply Voltage

Procedure for changing the unit's supply voltage, including case removal and plug reconnection.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The KENWOOD FG-272 is a Function Generator that also functions as a pulse generator and sweep oscillator.

Function Description

The FG-272 provides a wide range of oscillation frequencies, from 0.2 Hz to 2 MHz, across seven selectable ranges (1/10/100/1k/10k/100k/1M). It offers selectable output waveforms including sine waves, square waves, and triangle waves through one-touch operation. A dedicated TTL square wave output connector allows for easy use of TTL-level square waves as a signal source for digital circuit experiments.

A key feature is the Symmetry Function, which allows for varying the symmetry of saw-tooth waves and pulse waves, and also enables inversion of the wave polarity. External sweep and output frequency control can be implemented by applying a voltage from 0 to +10V to the VCF IN connector. The linear sweep function provides sweep frequency control up to a maximum ratio of 100:1, with sweep frequency variable from 0.5 Hz (2 seconds) to 50 Hz (20 milliseconds). DC voltage (0 to ±10V) can be overlaid upon the output waveform. The device also features an ATT -20 dB pushbutton and a continuous attenuator, providing a maximum attenuation of over 40 dB. Its compact and lightweight design includes a convenient carrying handle that doubles as a tilting stand.

Important Technical Specifications

General:

• Output Waveform: Sine wave, square wave, triangle wave, pulse wave, TTL-level square wave, and ramp wave.
• Oscillation Frequency Range: 0.2 Hz to 2 MHz (7 ranges).
• Frequency Accuracy: ±5% of full scale.
• External Frequency Control (VCF):
  • Input Voltage: 0 to +10V; frequency increases with positive voltage.
  • Frequency Variable Range: 100:1 or more.
• DC Offset: ±10V (open circuit), ±5V (into 50Ω), continuous variable.
• Polarity: Inverted or non-inverted.

Sine Wave:

• Distortion Ratio: 1% or less (10 Hz to 100 kHz).
• Output Frequency Response: Within ±1.0 dB up to 100 kHz (into 50Ω at max. output level).
• Output: Variable.

Square Wave:

• Symmetry: ±3% or less (at 100 Hz).
• Rise/Fall Time: 100 ns or less (at max. output level).
• Output: Variable.

Triangle Wave:

• Linearity: 1% or less (at 100 Hz).
• Output: Variable.

TTL Output:

• Rise/Fall Time: 25 ns or less.
• Output: TTL level.

Sweep Characteristics:

• Internal Sweep: Linear.
• Sweep Frequency: 0.5 Hz (2 sec) to 50 Hz (20 msec), continuous variable.
• Sweep Width: 1:1 to 100:1, peak-to-peak variable and continuous variable.
• External Sweep: By means of VCF input (Input impedance: 13 kΩ).

Output Characteristics:

• Output Voltage: 20 Vpp or more (open circuit), 10 Vpp or more (into 50Ω).
• Attenuator: -20 dB step, and continuous variable.
• Impedance: 50Ω ±10%.

Power Supply:

• Input Voltage: 100/120/220/240 VAC ±10% (Max. 250V AC).
• Frequency: 50/60 Hz.
• Power Consumption: Approx. 20 VA.

Environmental Conditions:

• Storage Temperature: -20 to 60°C, 70% or less relative humidity.
• Operating Temperature: 0 to 40°C, 80% or less relative humidity.
• With Specifications: 23 ±5°C, 70% or less relative humidity.

Size & Weight:

• Dimensions (WHD): 240 × 64 × 190 mm.
• Weight: 1.8 kg.

Accessories:

• Instruction Manual: 1
• AC cable: 1
• Fuse (0.3AT): 1
• Fuse (0.2A): 1

Usage Features

Front Panel Controls:

• POWER Pushbutton (1): Turns the unit on/off, with an LED indicator.
• RANGE (Hz) Selector Switch Assembly (2): Selects one of seven oscillation frequency ranges.
• FUNCTION Selector Switch Assembly (3): Selects output waveform (sine, triangle, or square).
• ATT -20 dB Pushbutton (4): Attenuates the output signal by 20 dB.
• INVERT Pushbutton (5): Inverts the polarity of the output waveform when engaged.
• MAIN/PULSE OUTPUT Jack (6): Outputs the selected waveform (sine, triangle, square) or pulse wave regardless of the FUNCTION switch setting.
• AMPLITUDE Control (7): Varies the amplitude of the output waveform.
• DC OFFSET Control (8): Pulling this knob allows admixing DC voltage with the output signal. Clockwise rotation adds positive voltage, counterclockwise adds negative voltage.
• DUTY/PULL TO VARI (Symmetry Adjustment) Control (9): Controls the symmetry of the output signal. Pulling this knob and rotating it clockwise varies the duty ratio from 1:1 to 5:1, affecting pulse, ramp, saw-tooth, and asymmetric sine waves. Note that this control also changes frequency.
• FREQUENCY Control Dial (10): A variable potentiometer that adjusts the frequency within the range selected by the RANGE switch. Scaled from 0.2 to 2.0.
• SWEEP Selector Pushbutton (11): Engaged for internal sweep, released for external sweep.
• SWEEP RATE Control (12): Controls the sweep rate (sweep frequency) of the internal sweep oscillator.
• SWEEP WIDTH Control (13): Controls the sweep width.

Rear Panel Connectors:

• VCF Input Jack (14): Used for external frequency control. When the SWEEP selector pushbutton is released, applying 0 to 10V to this jack varies the output signal frequency up to a maximum ratio of 100:1.
• Power Connector (15): For AC power supply. Requires the dedicated power cord.
• Fuse Holder (16): Holds the fuse for AC power supply.

Maintenance Features

Fuse Replacement: If the fuse blows, the cause should be identified and eliminated before replacing it. Use a 0.3 A slow-blow fuse for 100 to 120 V supply voltage, or a 0.2 A fuse for 220 to 240 V supply voltage. The fuse holder is located on the rear panel.

Changing Supply Voltage:

• WARNING: Always disconnect the power cord from the socket before opening the case.
• How to Remove Case: Turn the unit upside down, remove four screws from the case base plate, and then lift the base plate.
• How to Change Supply Voltage: The FG-272 supports supply voltages of 100, 120, 220, and 240 VAC, 50/60 Hz. To change the voltage, remove the case and reconnect the voltage selector plug on the printed circuit board to the desired voltage position on the voltage terminal board.

Precautions:

• Avoid using the FG-272 in direct sunlight, very hot and humid rooms, rooms with excessive mechanical vibrations, or near devices that irradiate strong magnetic forces or pulse voltage.
• While the unit operates immediately upon power-on, allow it to warm up sufficiently after pressing the POWER switch for accurate measurements.
• Do not repeatedly switch the Generator on and off.
• Refer to the "MAINTENANCE" section for instructions on changing the supply voltage.

Kenwood FG-272 Specifications