Icom IC-20L User Manual

Overview of the IC-3PS AC power supply and speaker stand for portable transceivers.

Introduction to linear amplifiers that boost transceiver output from 3W to 10W.

Highlights the small size and light weight of the linear amplifiers for easy mounting.

Describes the single power cord socket for simplified battery or external power connections.

Explains the large extruded aluminum heat sink for stable output during prolonged operation.

Details the APC circuit that protects the final stage transistor from antenna faults.

Describes the circuit that bypasses the amplifier for direct transceiver-to-antenna connection.

Lists detailed specifications for the IC-3PS, including input, output, and current ratings.

Provides specifications for the IC-50L, covering frequency, modulation, and power requirements.

Details specifications for the IC-20L, including frequency coverage, modulation, and power.

Outlines specifications for the IC-30L, covering frequency, modulation, and power requirements.

Enumerates the accessories provided with the IC-3PS unit.

Lists accessories included with the IC-50L, IC-20L, and IC-30L linear amplifiers.

Identifies all controls, connectors, and indicators on the front and rear of the IC-3PS.

Instructions for attaching a transceiver to the right side rack of the IC-3PS.

Steps to detach and transfer the rack for mounting a transceiver on the left side of the IC-3PS.

How to connect a transceiver to use the IC-3PS as an external speaker, with a caution.

Instructions for using the IC-3PS to power transceivers via AC, including specific cable requirements.

Identifies controls and connectors on the front and rear panels of the IC-50L, IC-20L, IC-30L.

Step-by-step guide to physically mount a linear amplifier into the IC-3PS unit.

Diagrams illustrating cable connections for various transceivers with linear amplifiers.

Diagrams showing specific cable connections for the IC-202S transceiver with linear amplifiers.

Instructions on setting power switches and AMP switches for transceiver and amplifier operation.

Guidelines for using external power supplies, including voltage, current, and polarity.

Explanation of the APC circuit's function in protecting the amplifier from high SWR conditions.

Instructions for using the mobile mounting bracket and options for transceiver/amplifier placement.

Explains the power amplifier circuit, including amplification, filtering, and output stages.

Describes the direct connection path for transceiver signals when the amplifier is bypassed.

Details the bias circuit that prevents thermal runaway by regulating voltage and compensating bias.

Explains the T/R switching circuit and its control over relays for signal path selection.

Explains the IC-30L power amplifier circuit, amplification, harmonic suppression, and output.

Describes the direct antenna connection for IC-30L when bypassed or in receive, noting signal loss.

Details the bias voltage regulator circuit for preventing thermal runaway and stabilizing bias.

Explains the APC circuit's logic for detecting over-current and protecting the amplifier.

Details the APC control system using flip-flops and NAND gates for T/R switching and indicator control.

Presents the complete electronic schematic for the IC-3PS power supply unit.

Provides the detailed electronic schematic diagram for the IC-50L linear amplifier.

Presents the detailed electronic schematic diagram for the IC-20L linear amplifier.

Details the complete electronic schematic diagram for the IC-30L linear amplifier.

Describes the optional mobile mounting kit for easy installation of linear amplifiers in vehicles.

Presents the IC-SM2 desk microphone, featuring an electret condenser element and pre-amplifier.