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Model MFJ-989D 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 COPYRIGHT 2014 MFJ ENTERPRISES, INC. VERSION 2A...
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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's top-of-the-line high- power Guanella current-style balun. Before attempting to use your MFJ-989D for the first time, we urge you to read through the entire manual. Doing so will help you gain familiarity with all of the MFJ-989D's many functions and features.
2.) 12-VDC External Power: The Meter Lamp power jack is located above the Transmitter connector on the rear panel. Apply power from any filtered dc wall adapter (MFJ-1312D or equivalent), or use your station's 13.8-Vdc supply. A cord fitted with a 2.1-mm plug is supplied with the tuner for this purpose.
MFJ-989D VersaTuner V Instruction Manual 2.1 mm Important Note: You don't need to disconnect the battery when using external dc power. It is protected from back-feed and won't be damaged by the other source. Important Warning: Never connect an ac-voltage or positive-ground source to the Meter Lamp jack...
MFJ-989D VersaTuner V Instruction Manual 8. Power PK/AVG: Selects the meter detection (Peak or Average).** 9. Lamp On/Off: Turns meter's LED lighting on or off.** NOTE* The control scales track frequency rather than component value. Tuned circuits typically require progressively lower values of L and C as frequency increases.
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As previously noted, the MFJ-989D incorporates five very useful station accessories into a single package. Here are operating instructions for each one, beginning with the power meter and SWR bridge.
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MFJ-989D VersaTuner V Instruction Manual [ ] Select a forward Power range (LO for 300-W or HI for 3-kW). [ ] Select PK for peak-power readings or AVG for average-power readings. [ ] View the Forward scale to read incident power.
Never apply power levels exceeding 300-Watts for even short durations. Doing so could permanently alter the resistor's value or catastrophically destroy it. Heat damage to other tuner components could result, as well! Important Warning: Never tune a high-power linear amplifier into the MFJ-989D Dummy Load or permanent damage will result! 1:1 Balun A built-in Guanella-style current balun is used to transition from the tuner's unbalanced Wire terminal to the Bal.
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MFJ-989D VersaTuner V Instruction Manual Balun Wire Install Jumper Wire Bal. Line < To place the balun in line and energize the Bal. Line terminals, connect a Jumper from the unbalanced Wire terminal post to the terminal post directly below it. The jumper-wire path is labeled on back panel for reference.
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(normalized to 50-Ohms) and let the tuner do the matching! Important Warning: Never apply high power to the MFJ-989D before it has been fully adjusted for minimum SWR. Always tune unknown antenna loads using the least amount of power needed to obtain a useful SWR reading (25 Watts or less).
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(Antenna > Inductor > Transmitter). Try to find the lowest front panel capacitor settings that will allow you to obtain minimum SWR. The chart below shows sample control settings for a MFJ-989D recorded in our lab using 50-Ohm unbalanced and 600-Ohm balanced loads. Your optimum settings will vary somewhat, depending on the characteristics of your particular antenna.
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Many linear amplifiers are capable of exceeding the 1500-Watt legal power limit -- some delivering 2800 Watts or more! These BIG amplifiers should always be tuned up for their maximum rated output. However, don't tune them it through the MFJ-989D, or permanent damage to the routing switch and other internal components may result!
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MFJ-989D VersaTuner V Instruction Manual MFJ-989D! Then, reduce exciter power to bring output well below 1500-Watts before connecting to your tuner. After it is connected, you can readjust the exciter while monitoring amplifier's power on the tuner's wattmeter. When running SSB, be sure to use the SWR / Wattmeter's PK (peak power) setting for...
Important Warning: For operator safety, always install a good earth ground and connect it directly to the case of the MFJ-989D. A terminal post marked GND is provided on the back panel for a secure connection.
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*Some slight trimming or adding of length may be necessary to accommodate the higher bands. Factory Technical Assistance If you have any problem with your MFJ-989D, first check the appropriate section of this manual. If the manual does not reference the problem or succeed in solving it, call (a.) MFJ Technical Service at 662- 323-0549 or (b.) the MFJ Factory at 662-323-5869.
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MFJ-989D VersaTuner V Instruction Manual Tuner Log Use the chart below to log tuner settings for your station. You may want to copy this chart and post it by your tuner. Frequency Transmitter Inductor Antenna 3.75 3.75 3.75 7.15 7.15 10.1...
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MFJ-989D VersaTuner V Instruction Manual NOTES:...
MFJ Enterprises, Inc. warrants to the original owner of this product, if manufactured by MFJ Enterprises, Inc. and purchased from an authorized dealer or directly from MFJ Enterprises, Inc. to be free from defects in material and workmanship for a period of 12 months from date of purchase provided the following terms of this warranty are satisfied.
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MFJ-989D Manual 300 Industrial Park Road Version 2A Starkville, MS 39759 Printed In U.S.A.
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