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MFJ Manuals & User Guides

User manuals, setup guides, troubleshooting help, and repair information for MFJ products.

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User Manuals, Instructions and Guides for MFJ products.

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MFJ-401C Econo Electric Keyer Owner’s Manual

August 2, 2025

MFJ-401C Econo Electric Keyer The MFJ-401C econo-keyer provides iambic key operation and dot-and-dash memory to make sending easier. Please read all instructions before attempting to operate the keyer. INSTALLATION The…

MFJ-401E SlimLine Econo Keyer Instruction Manual

July 1, 2025

MFJ-401E SlimLine Econo Keyer Specifications Model: MFJ-401E Brand: SlimLine Keyer Type: Econo Keyer with Memory Control Functions: Power ON/OFF, Semi-Auto/Auto, Message Record/Play, Tone Control, Volume Control, Iambic Type A/B Supports:…

MFJ-1118D High Current Power Strip with Digital Voltage Meter Instructions

January 4, 2024

MFJ-1118D High Current Power Strip with Digital Voltage Meter Instructions INTRODUCTION Thank you for purchasing the MFJ-1118D High Current Multiple DC Outlet with Digital LED Voltmeter. The MFJ-1118D is very…

MFJ-1622 Apartment Antennas Instruction Manual

December 26, 2023

MFJ-1622 Apartment Antennas Frequency and SWR Adjustment The antenna is tuned to the operating frequency by adjusting the tap on the loading coil and the length of the counterpoise wire.…

MFJ-1622 Window Mount Antenna Instruction Manual

December 26, 2023

MFJ-1622 Window Mount Antenna Introduction The MFJ-1622 Antenna was designed to provide portable or permanent HF communications at 40 through 10 meters and VHF on 6 and 2 meters. The…

MFJ-8100K World Band Swl Receiver Kit Instruction Manual

November 15, 2023

MFJ-8100K World Band Swl Receiver Kit VERY IMPORTANT! PLEASE READ Your receiver kit is covered by MET's No Matter What guarantee specifically to the extent that you may return the…

MFJ-962E VersaTuner III Network Roller Inductor Tuner Instruction Manual

July 25, 2023

MFJ-962E VersaTuner III Network Roller Inductor Tuner Instruction Manual Introduction The MFJ-962E is a "T" network roller inductor tuner with built-in antenna switching, RF power and SWR metering, and a…

MFJ-249D HF VHF SWR Analyzer Instruction Manual

September 17, 2022

HF/VHF SWR Analyzer Model MFJ-249D INSTRUCTION MANUAL CAUTION: Read All Instructions Before Operating Equipment INTRODUCTION Attention: Read Section-2.0 before attempting to use your analyzer. Incorrect power supply voltages or excessive…

MFJ-933C High-Efficiency Magnetic Loop Tuner Instruction Manual

June 3, 2022

933C High-Efficiency Magnetic Loop Tuner Instruction Manual MFJ Enterprises, Inc. 300 Industrial Park Rd. Starkville, MS 39759 P: (662) 323-5869 F: (662) 323-6551 DISCLAIMER The information in this manual is…

MFJ-1205 DigiLINK USB Radio Interface Instruction Manual

June 2, 2022

MFJ-1205 DigiLINK USB Radio Interface DISCLAIMER The information in this manual is for user purposes only and is not intended to supersede information contained in customer regulations, technical manuals or…

MFJ-4403 Transceiver Voltage Conditioner Instruction Manual

Instruction Manual

Instruction manual for the MFJ-4403 Transceiver Voltage Conditioner by MFJ Enterprises. This device provides input transient voltage protection, reverse polarity protection, and noise filtering for transceivers, enhancing operational reliability for…

MFJ-918 1:1 Current Balun: Installation and Operation Manual

Instruction Manual

Detailed instruction manual for the MFJ-918 1:1 current balun, covering its features, installation steps, and important safety warnings for amateur radio operators.

MFJ-2982 Feather-Lite 80-6 Meter Vertical Antenna: Installation and Tuning Guide

Installation Guide

Comprehensive guide for installing and tuning the MFJ-2982 Feather-Lite 80-6 Meter Vertical Antenna. Includes parts list, setup instructions, mounting hardware details, and troubleshooting tips for amateur radio operators.

MFJ-422D/422DX Electronic Keyer Paddle Instruction Manual

Instruction Manual

This manual provides detailed instructions for the MFJ-422D and MFJ-422DX Electronic Keyer Paddle. It covers setup, control functions, installation, connections, operation, Morse code charts, and jumper settings for amateur radio…

MFJ-422E/422EX Electronic Keyer Paddle with Memory Instruction Manual

Instruction Manual

Instruction manual for the MFJ-422E/422EX Electronic Keyer Paddle with Memory, detailing its features, operation, installation, and troubleshooting for amateur radio enthusiasts.

MFJ-927 Remote Intellituner Automatic Antenna Tuner Instruction Manual

Instruction Manual

Optimize your amateur radio setup with the MFJ-927 Remote Intellituner Automatic Antenna Tuner. This comprehensive instruction manual guides you through installation, operation, advanced features, and safety precautions.

MFJ-721 Audio Filter User Manual - Installation and Operation Guide

User Manual

Comprehensive user manual for the MFJ-721 Audio Filter, detailing installation, operation modes (SSB, CW), selectivity settings, and technical specifications. Includes schematic and component information for amateur radio enthusiasts.

MFJ SWR-584B HF/VHF SWR Analyzer Instruction Manual

Instruction Manual

This document provides detailed instructions and operational guidance for the MFJ SWR-584B HF/VHF SWR Analyzer, a versatile tool for radio frequency impedance measurements and antenna testing.

MFJ 2017 Ham Catalog: Antenna Tuners and Radio Accessories

catalog

Explore the MFJ 2017 Ham Catalog, featuring a comprehensive range of high-performance antenna tuners, SWR meters, analyzers, power supplies, and essential ham radio accessories from MFJ Enterprises.

MFJ-1104 Mini 4-Way Fused DC Power Distribution Unit - MFJ Enterprises

Technical Specification

Detailed information on the MFJ-1104 Mini 4-Way Fused DC Power Distribution Unit, including product specifications, usage guide, technical support contacts, and the 12-month limited warranty from MFJ Enterprises.

MFJ-939 Plug&Play IntelliTuner Automatic Antenna Tuner Instruction Manual

Instruction Manual

This instruction manual provides comprehensive guidance for the MFJ-939 Plug&Play IntelliTuner™ Automatic Antenna Tuner. It is designed to help amateur radio enthusiasts install, configure, and operate the tuner with various…

MFJ-1204 USB Radio Interface User Manual

Instruction Manual

This user manual provides comprehensive instructions for setting up, connecting, and operating the MFJ-1204 USB Radio Interface for ham radio digital communication. It covers features, radio and computer connections, software…