MFJ MFJ-9982 User Manual

2500 Watt SSB / CW Tuner

Model MFJ-9982

INSTRUCTION MANUAL

Requires 9V Battery or 12V DC Source for Meter Operation

CAUTION: Read All Instructions Before Operating Equipment

VERSION 1D

MFJ ENTERPRISES, INC.

300 Industrial Park Road
Starkville, MS 39759 USA

Tel: [phone] Fax: [phone]

COPYRIGHT 2006 MFJ ENTERPRISES, INC.

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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: [phone]; FAX: [phone]. Business hours:
M-F 8-4:30 CST.

MFJ-9982 2500 Watt Antenna Tuner Instruction Manual

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1.0 Introduction

The MFJ-9982 is a high power antenna tuner that will operate at power levels up to 2500 watts SSB or
CW. The MFJ-9982 uses an edge would roller inductor in a matching “T” network to continuously tune

loads between 1.8 and 30 MHz. The MFJ-9982 uses an edge would roller inductor in a matching “T”
network to continuously tune loads between 1.8 and 30 MHz. The tuner also features a true peak or
average reading SWR/Wattmeter.

The MFJ-9982 will match dipoles, inverted-vees, verticals, mobile whips, beams, random wires, and
many other antennas. The MFJ-9982 has rear panel connectors for coaxial and single wire or balanced
feedlines. The balanced feedlines are isolated from the tuner chassis with a fiberglass panel to reduce
capacitive coupling and withstand high voltages and handle high currents.

The MFJ-9982 is designed to match 50 ohm output amplifiers, transmitters or transceivers to virtually
any antenna with an impedance ranging from 12.5-2000 ohms on 3.5-30 MHz. The tuner will match
loads ranging from 12.5-800 ohms on 1.8-3.5 MHz.

Peak and average forward power, reflected power, and SWR are displayed on the MFJ-9982's
illuminated cross-needle meter. An internal six-position antenna selector switch selects a built-in 50
ohm dummy load, two coaxial line outputs, or a single wire/ balanced line output. The coaxial line
outputs can be selected in tuned (with tuner's matching network in line) or direct (no matching circuit)
configurations.

Understanding Power Ratings

Load conditions and control settings greatly affect the power handling capability of the tuner. T­networks typically handle more power on higher frequency bands into higher load impedances. The
worst operating condition for T network tuners are low impedance capacitive reactance loads. T­network tuners always handle the least power when operated on 160 meters into low impedance
capacitive reactive loads.

Follow the guidelines in this manual to avoid exceeding the ratings of this tuner.

True Active Peak Reading SWR/Wattmeter

The cross-needle meter measures the peak or average FORWARD power, REFLECTED power, and
SWR. The illuminated cross-needle meter operates with the antenna tuning circuit in or out of line. The
wattmeter can be used without the tuning network by setting the ANTENNA SELECTOR to either of
the two COAX DIRECT positions of the antenna selector. The wattmeter is active in all positions of
the ANTENNA SELECTOR. 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.

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”
batter

.

The meter's full scale forward and reflected power range is controlled by the RANGE switch that selects
HI (3000W) or LO (300W). If your transmitter runs more than 300 watts of output power, set this

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MFJ-9982 2500 Watt Antenna Tuner Instruction Manual

switch to the HI (in) position. If your transmitter has less than 300 watts of output, set this switch to the
LO (out) position.

Peak envelope power (PEP) is measured when the PK or AVG POWER push button (center) in placed
in the PK (in) position. Peak power and average power values are equal with steady unmodulated
carriers, FSK, or FM. The meter reading on these modes will be the same whether the PK / AVG
button is pressed or released. On SSB, the PEP meter reading should be twice the average power with
two tone test modulation.

On SSB, the ratio of PEP to average power varies with different voice characteristics. With most
voices, the PEP reading is three to five times higher than the average voice power reading. The most
accurate peak envelope power readings are obtained only with sustained carrier, voice or two tone test
modulation. During normal voice modulation the wattmeter will typically indicate only 70% of the true
peak envelope power.

Forward power is displayed on the left-hand FORWARD meter scale. This scale is calibrated from 0 to
300 watts and is read directly in the 300W (LO) position. Each picket (scale mark) represents 5 watts
below 10 watts, 10 watts between 10 and 100 watts, and 25 watts between 100 and 300 watts. In the
3000W (HI) position, the forward power scale must be multiplied by 10. Each picket represents 50
watts below 100 watts, 100 watts from 100 to 1000 watts, and 250 watts from 1000 to 3000 watts.

The reflected power is read on the right-hand REFLECTED meter scale. Reflected power is 60 watts
full scale when the 300W (LO) power sensitivity is selected, and 600 watts full scale when the 3000W
(HI) power scale is selected.

The most accurate power readings occur in the upper half of the meter scales. When trying to measure
power with a less than perfect match, the reflected power should be subtracted from the forward power
reading in order to find the true power.

The SWR is read directly from nine red SWR curves that range from 1:1 to infinity. SWR is measured
by observing the point where the forward and reflected power needles cross. The SWR is indicated by
the red curve closest to the needle crossing point. No cumbersome or time-consuming SWR sensitivity
adjustments are required with this meter.

NOTE: The wattmeter must have a power source in order to function. A nine-volt battery may
be installed in the compartment on the rear panel, or an external 12 Vdc source, such as the
optional MFJ-1312D power supply, may be used.

The rear panel jack accepts a 2.1 mm coaxial plug with the center conductor positive (+) and the sleeve
negative (-). The negative lead is grounded inside the tuner. There is no need to disconnect the battery
when using external power. An internal lamp backlights the meter scale. The lamp circuit requires
power from an external 12 Vdc source and will not illuminate unless an external supply is used. The
LAMP ON / OFF switch turns the meter lamp on and off.

CAUTION: It is not recommended that the tuner be operated without a battery installed. The battery
leads may otherwise make contact with internal components carrying high voltage, causing
permanent damage to the meter circuit. For this reason, the battery leads are attached to the chassis
prior to shipment.

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MFJ-9982 2500 Watt Antenna Tuner Instruction Manual

Antenna Selector

The ANTENNA SELECTOR allows you to select 2 rear panel SO-239 coaxial connectors either direct
or through the tuner, a 50 ohm dummy load, and single wire or balanced feedline antennas. The 50 ohm
DUMMY LOAD can be used for 10 minutes at a power level of 100 watts and a maximum of 10
seconds at 1.5kw. If these times are exceeded damage may occur to the tuner.

Installation

WARNING: Locate the tuner so the rear is not accessible during operation. High Voltages will be

present on the terminals. Serious Injury will occur if contact is made with connectors.

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 battery.

1. Locate the tuner in a convenient location at the operating position. If random wire or balanced line
operation is used, the ceramic feed through insulators will have high RF voltages. These voltages
can cause serious RF burns if the terminals are touched when transmitting. Be sure to locate the

tuner so these terminals can not be accidentally contacted during operation.

2. Install the tuner between the transmitter and the antenna as shown in figure 1 below. Use a coaxial

cable (such as RG-8/U) to connect the transmitter (or amplifier) to the connector marked
TRANSMITTER on the rear of the tuner.

Figure 1

3. Connect the antenna(s) to the tuner as follows:

IMPORTANT: The aluminum jumper must be placed from the ground terminal to the bottom balanced

line terminal for COAX 1, COAX 2, or Random Wire Operation. See figure 1.

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