AMERITRON AL-80B User Manual

AL-80B Instruction Manual
i
WARNING!!!
NEVER APPLY POWER TO THIS AMPLIFIER WITH THE COVER REMOVED!
CONTACT WITH THE VOLTAGES INSIDE THIS AMPLIFIER CAN BE FATAL!
PLEASE READ THIS MANUAL BEFORE ATTEMPTING TO OPERATE EQUIPMENT!
Improper or abusive operation of this amplifier can damage the tubes or other components in
this amplifier. Damage caused by improper or abusive operation is not covered under the
warranty policy.

AMERITRON AL-80B Specifications

General

Input Impedance	50 Ohms
Output Impedance	50 Ohms
Cooling	Forced air
ALC	Yes
Power Supply	2400 Volts

Summary

Critical High Voltage Warning

Unpacking and Initial Setup

Fuse and Voltage Precautions

Key Amplifier Features

Technical Specifications Overview

Introduction to the AL-80B

Safety Interlock System

Details the function and importance of the amplifier's safety interlock switch.

Essential Safety Precautions

Crucial safety guidelines and personal precautions for operating the amplifier.

Circuit Descriptions

Automatic Level Control (ALC) Circuit

Explains the ALC circuit's function, sampling, and adjustment for distortion minimization.

Dynamic Bias Circuit Operation

Details the exclusive bias circuit that reduces idling current and heat generation.

Power Supply Details

Plate (High Voltage) Supply

Meters and Indicators

Plate and Grid Current Metering

Multimeter Functions Explained

Multimeter Metering Functions

Wattmeter Circuit and Power Measurement

Peak Envelope Power vs. Average Power

Tube and Component Longevity

Power Connections

Grounding Procedures for Safety

Transformer Connections and Voltage Setup

Interconnections and Cabling

Front Panel Control Adjustments

PLATE and LOAD Control Adjustments

ALC Metering and Controls

ALC Metering Functions

ALC Controls and Adjustments

ALC SET Control Adjustment

Sets the grid current threshold for ALC action, affecting power and linearity.

ALC Adjustments for SSB Operation

Adjusting ALC for best audio quality, talk power, and linearity on SSB.

Rear-panel ALC Limit Control

ALC Limit Adjustment Procedure

Driving Power Requirements

Tuning Procedure

Tuning Steps for Optimal Output

Step-by-step guide for tuning the amplifier for optimal output and signal quality.

ALC SET Control Operation

Additional SSB Operation Notes

Periodic Maintenance Procedures

Maintenance Safety and Cleaning

Service Safety Precautions

Safety measures to follow when performing service or maintenance on the amplifier.