MFJ MFJ-868 User Manual

Model MFJ-868

VERSION 1A

INSTRUCTION MANUAL

CAUTION: Read All Instructions Before Operating Equipment

MFJ ENTERPRISES, INC.

300 Industrial Park Road

Starkville, MS 39759 USA

Tel: 662-323-5869 Fax: 662-323-6551

DISCLAIMER

Information in this manual is designed for user purposes only and is not intended to supersede information contained in customer regulations, technical manuals/documents, positional handbooks, or other official publications. The copy of this manual provided to the customer will not be updated to reflect current data.

Customers using this manual should report errors or omissions, recommendations for improvements, or other comments to MFJ Enterprises, 300 Industrial Park Road, Starkville, MS 39759. Phone: (662) 323-5869; FAX: (662) 323-6551. Business hours: M-F 8-4:30 CST.

MFJ-868 Giant SWR/Wattmeter Instruction Manual

MFJ-868 Giant SWR/Wattmeter

Introduction

The MFJ-868 Giant SWR/Wattmeter is the World’s Largest HF SWR/Wattmeter. The MFJ-868 measures peak or average forward and reflected power as well as standing wave ratio. It is designed to operate on 1.8-30 MHz. The MFJ-868 has three power scales, which are selected with the front panel slide switch. The high power scale measures 02000 Watts forward or reflected power. The mid power scale measures 0-200 Watts forward and reflected power. The low power scale measures 0-20 Watts forward and reflected power. MFJ’s exclusive Power Saver circuit turns the meter on only when RF power is being measured. The MFJ-868 utilizes a large illuminated 6.5-inch SingleNeedle meter to read the SWR from 1:1 to ∞.

Features

• Huge Backlit Meter: 6.5 in. measured diagonally across the front.

• Easy-to-Read Scales: Large numbers and pickets make reading a breeze.

• Power Saver Circuit: Meter turns on only when transmitting.

• Three Power Scales: 20/200/2000 Watt power scales.

• Forward and Reflected: Measures forward power and reflected power.

• Peak or Average Reading: Measures Peak or Average power.

• Power or SWR: Measures Power and SWR.

• Easy-to-Set SWR: Easy set for accurate SWR measurements.

• Frequency Range: 1.8 - 30 MHz.

• Input/Output Impedance: 50 Ohms.

WR SET

MAXMIN

OFF

20W

MFJ-868

MFJ SWR/Wattmeter

Giant

200W

PEAK

2kW

AVG

SWR

PWR

REF SWR

FWD SET

Figure 1: Controls

Controls

1. 20W / 200W / 2kW switch: Selects between 20, 200, 2000-Watt power scales.

2. PEAK/AVG switch: Selects Peak or Average power measurement.

3. SWR/PWR switch: Selects Power or SWR measurement.

4. REF/FWD switch: Selects forward or reflected power measurement.

5. SWR/SET switch: Selects SWR measurement or set.

6. SWR SET knob: Sets full-scale deflection to measure SWR.

7. ON/OFF switch: Turns power to the unit and lamp on or off.

MFJ-868 Giant SWR/Wattmeter Instruction Manual

Installation

1. Connect your transmitter to the connector labeled TRANSMITTER and your antenna to the connector labeled ANTENNA. It is important that you use good quality coax and properly installed connectors.

2. The meter must have a power source in order to function. Power can be provided by an external 12 VDC supply such as the MFJ-1312B or an internal nine-volt “transistor radio” battery. Use a 2.1 mm coaxial plug with the center conductor positive and the sleeve ground. MFJ’s exclusive Power Saver circuit turns the meter on only when RF power is being measured.

3. An internal lamp backlights the meter scale. The lamp requires a 12 VDC supply such as the MFJ-1312B. Use a 2.1 mm coaxial plug with the center conductor positive and the sleeve ground. The ON/OFF switch turns the unit and internal lamp on or off.

Note: The meter must have a power source in order to function. Power can be provided by an external 12 VDC supply (negative ground only) or an internal nine-volt “transistor radio” battery.

4. To measure the power output capability of a transmitter/amplifier you should connect a quality 50-ohm dummy load to the ANTENNA connector of the MFJ-

868.

Operation

Power Measurement Settings

1. Set the SWR/PWR switch to PWR (out) for power measurement.

2. Set the REF/FWD switch to FWD (out) for forward power measurement or to REF (in) for reflected power measurement. (REF/FWD and SWR/SET settings share the same switch.)

3. Select peak or average reading by setting the PEAK/AVG switch to the desired position. Set to AVG (out) to read average RF power. Set to PEAK (in) for use with SSB and AM transmissions. In this mode, there will be a slow rise and decay time.

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