MFJ MFJ-927 User Manual

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Page 1

Model MFJ-927

INSTRUCTION MANUAL

VERSION 1A

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

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

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) 3235869; FAX: (662) 323-6551. Business hours: M-F 8-4:30 CST.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Contents

THE BASICS

Introduction...................................................................................................................................... 1

Features............................................................................................................................................ 2

Specifications................................................................................................................................... 2

Fast Start .......................................................................................................................................... 3

Internal Components........................................................................................................................ 4

SWR LED........................................................................................................................... 4

TUNE LED ......................................................................................................................... 4

TUNE Button...................................................................................................................... 4

Automatic/Semi-Automatic Tuning Mode ............................................................ 4

ANT Button ........................................................................................................................ 5

POWER Button................................................................................................................... 5

Connections ..................................................................................................................................... 5

Transmitter.......................................................................................................................... 5

Antenna............................................................................................................................... 5

Ground ................................................................................................................................ 5

Wire .................................................................................................................................... 5

Installation ....................................................................................................................................... 6

MISCELLANEOUS

Antenna Memory ............................................................................................................................. 7

IntelliTune

LC Limits......................................................................................................................................... 7

Morse Code and Flashes .................................................................................................................. 8

Foldback Circuit .............................................................................................................................. 8

Grounding Hints .............................................................................................................................. 9

Antenna System Hints...................................................................................................................... 9

APPENDICES

Resetting the Tuner........................................................................................................................ 11

Algorithm .................................................................................................................. 7

Location .............................................................................................................................. 9

Matching Problems ............................................................................................................. 9

Factory Defaults................................................................................................................ 11

Delete Entire Antenna Memory ........................................................................................ 12

Delete Antenna Memory Bank .........................................................................................12

Total Reset ........................................................................................................................ 12

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Self Test ......................................................................................................................................... 13

Power-Down Circuit Test .............................................................................................................. 14

Relay Test ...................................................................................................................................... 14

Frequency Counter Calibration...................................................................................................... 15

SWR Bridge Calibration ................................................................................................................ 15

In Case of Difficulty ......................................................................................................................16

Technical Assistance...................................................................................................................... 17

List of Accessories......................................................................................................................... 17

Limited Warranty........................................................................................................................... 19

FIGURES

Figure 1. Installation Block Diagram.............................................................................................. 3

Figure 2. Power-On Operations .................................................................................................... 11

TABLES

Table 1. Memory Resolution ..........................................................................................................7

Table 2. Tuner Flashes.................................................................................................................... 8

Table 3. Failure Messages............................................................................................................. 13

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

The Basics

Introduction

The MFJ-927 IntelliTuner MFJ's exclusive InstantRecall tuning with more than 20,000 non-volatile VirtualAntenna

memory; each memory bank has over 2500 non-volatile memories for tuner settings.

The tuner includes a highly efficient switching L-network with wide matching capability, 1.8 to 30 MHz coverage, a radio interface port, and heavy-duty 10 amp/1000 volt relays. It is rated at 200 watts SSB/CW.

A maximum of 256 values of inductance and 256 values of capacitance are available. With the capacitance switched between the input and output side, this provides a total of 131,072 L/C tuning combinations. The nominal tuning ranges are 0 to 24 μH and 0 to 3900 pF.

All MFJ IntelliTuners

SWR and remember the frequency and tuner settings, safely stored in non-volatile memory. The next time you operate on that frequency (or close to it) and antenna, these tuner settings are instantly restored and you’re ready to operate in milliseconds. The antenna has four banks of memory, which can learn and remember more than 2500 frequencies and tuner settings per bank.

When you key your transmitter, MFJ’s InstantRecall

that frequency before. If so, tuning is instantaneous and you’re ready to operate. If not, MFJ’s

IntelliTune

algorithm (based on MFJ’s famous SWR Analyzer technology) kicks in. It measures the complex impedance of your antenna. Next, it calculates the components it needs and instantly snaps them in. Finally, it fine-tunes to minimize SWR, and you’re ready to operate--all in a fraction of a second.

If the antenna impedance is not within the tuner’s measurement range, MFJ’s AdaptiveSearch

algorithm goes into action. Frequency is measured and relevant components values are determined. Only those values are searched for fast tuning. If it still cannot find a match, the search is performed again using a different search pattern.

The tuners enter a “sleep” mode when idle and when no transmit signal is present, turning off the microprocessor clock to avoid the generation of spurious signals.

lets you rapidly tune any antenna automatically: unbalanced or single-wire.

, IntelliTuneTM and AdaptiveSearch

learn and remember. When you transmit, they automatically adjust for minimum

checks its memory to see if you have operated

algorithms give you fast automatic

memories. Your antenna has four banks of

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Features

• Automatically matches antennas from 6 to 1600 ohms impedance (SWR up to 32:1)

• Handles 200 watts SSB/CW

• Tune in less than 15 seconds, usually less than 5 seconds

• Over 20,000 non-volatile memories for tuner settings

• Four memory banks with over 2500 memories per bank

• Highly efficient switching L-network matching circuit

• 1.8 to 30 MHz continuous frequency coverage

• Built-in bias tee

• SO-239 coax fed antenna connector

• Connector for random wire or single wire antennas

• Included external bias tee for remote operation

Specifications

• Impedance matching range: 6 to 1600 ohms

• SWR matching range: up to 8:1 for < 50 ohms and up to 32:1 for > 50 ohms

• Minimum power for tuning: 2 watts

• Maximum power while tuning: 100 watts with foldback, 20 watts without foldback

• RF power limit: 200 watts SSB/CW

• Frequency range: 1.8 to 30 MHz continuous coverage

• Capacitance range: 0 to 3961 pF nominal (256 values)

• Inductance range: 0 to 24.86 μH nominal (256 values)

• Relay rating: 10 amp 1000 volts

• Relay electrical life: 100,000 operations

• Relay mechanical life: 10 million operations

• Memory endurance: 1 million erase/write cycles

• Memory data retention: > 200 years

• Power requirements: 12 - 15 volts DC, 2.1 × 5.5 mm coaxial plug, center pin positive

• Current consumption: 750 milli-amp or less

• Dimensions (approx.): 7.5 × 5.5 × 9.0 in. (width/height/depth)

• Weight (approx.): 3.0lb

† Specifications and design are subject to change without notice.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Fast Start

WARNING

● Never operate the tuner with its cover removed. Contact with the components inside the tuner while transmitting will result in painful RF burns.

● Locate the tuner so that the terminals are not accessible during operation. The single wire connection may have high voltage while transmitting.

● Disconnect all antennas from the tuner during lightning storms.

● Always tune with low power (about 10 watts). Apply maximum power only after tuning up.

● Never exceed tuner specifications.

● Do not transmit with a high SWR for extended periods of time.

1. Connect the transmitter to the “RF IN/OUT” coaxial connector on the MFJ-4116 Bias-Tee

using a 50-ohm coaxial cable. (See Figure 1) This is the RF signal input connector.

2. Connect a 12-15 VDC voltage source capable of supplying at least 750 milli-amps to the “DC IN\OUT” jack on the MFJ-4116 Bias-Tee. This is your DC voltage input connector.

3. Connect the “RF/DC OUT/IN” coaxial connector on the MFJ-4116 Bias-Tee to the

TRANSMITTER connector on the MFJ-927 Intellituner using 50-ohm coaxial cable. The MFJ-927 Intellituner will recover the RF and DC signals.

4. Connect your coax-fed antenna to the ANTENNA connector using a 50-ohm coaxial cable, or connect your random wire to the WIRE binding post.

5. Connect your ground connection to the GROUND post.

6. Key your transmitter to output a carrier of 10 watts CW, FM or AM. Using an external SWR/Wattmeter, check to ensure an SWR of 2.0 or less before increasing RF power.

7. You are ready to transmit.

Note: During the automatic tuning process, the tuner will make some noise. These are the relays

switching at a very fast pace and it is normal operation. Do not be alarmed.

12-15

VDC input

1.8-30 MHz RF

input

MFJ-4116

Bias Tee

Figure 1: MFJ-927 and MFJ-4116 Installation Block Diagram

Note: To use the Random WIRE binding post, make sure to remove the antenna, if any, from

the ANTENNA connector.

DC / RF

MFJ-927

Intellituner

ANTENNA

RANDOM WIRE

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Internal Components

The MFJ-927 was designed for remote operation with no manual tuning required. The tuning process starts automatically when the transmitter is keyed with at least two watts of power regardless of the SWR. The unit will be set at the MFJ Factory, however, if something requires the unit to be removed from the box for calibration purposes, the following will guide you through the process.

• SWR LED: A green LED that illuminates when the SWR is 1.5 or less.

• TUNE LED: A red LED that illuminates when the automatic tuning is in progress.

• TUNE Button: Has three different functions based on the length of time you press and hold it before

releasing. Press [TUNE] quickly (less than 0.5 second) to bypass the tuner. One flash indicates bypass mode, where RF from the transmitter goes directly to the antenna with no matching. A second quick press toggles the tuner back to its last L/C setting, and the tuner responds with two flashes.

Press and hold [TUNE] for 0.5 to 2 seconds to start the automatic tuning process. The transmitter must be keyed first with at least two watts of power. When the SWR is already below the target SWR of 1.5, pressing [TUNE] will fine-tune the match for a lower SWR, if possible. When the automatic tuning is completed, a series of flashes indicates the tuned SWR where one flash indicates SWR of

1.5 or less, two flashes indicate SWR of 1.6 to 2.0, three flashes indicate SWR of 2.1 to 2.5, and four flashes indicate SWR of 2.6 to 3.0. For SWR above 3.0, “SWR” (di-di-dit di-dah-dah di-dah-dit) will be sent on CW.

“StickyTune” allows for one-handed tuning operation. Normal tuning requires keying the transmitter

with one hand and using the other hand to push the [TUNE] button to start the tuning process. To

toggle the StickyTune mode on and off, press and hold the [TUNE] button for two seconds. One

Flash indicates on and two Flashes indicate off. When enabled, the tuning process starts automatically when the transmitter is keyed with at least two watts of power regardless of the SWR.

This works in both automatic and semi-automatic modes. For remote operation, keep the StickyTune

mode on.

Automatic/Semi-Automatic Tuning Mode

Pressing [TUNE] and [ANT] simultaneously toggles between automatic and semi-automatic tuning mode. One Flash indicates automatic mode and two Flashes indicate semi-automatic mode. In automatic mode, the tuning routine is automatically started when at least two watts of power is applied and the SWR is greater than 2.5. In semi-automatic mode, the tuning routine starts only when the [TUNE] button is pressed for 0.5 to 2 seconds.

Note: During the tuning process, the tuner will make some noise. These are the relays

switching at a very fast pace and it is normal operation. Do not be alarmed.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

• ANT Button: One flash indicates Antenna 1 and two flashes indicate Antenna 2. You can store

memory for two separate antennas. When you change to a different antenna and want to store separate memory, press the ANT button.

• POWER Button: Used to turn the power on and off. When the power is off, the tuner is placed in

bypass mode and Antenna is selected. When turning on the power, the tuner automatically restores all previous settings and displays the target SWR on the main screen.

WARNING: Do not turn the power on and off rapidly, otherwise the tuning setting

memory can be corrupted and the unit will have to be reset to factory defaults.

Note: When the tuner power is OFF, the tuner is in bypass mode and RF from the transmitter

goes directly to the antenna (ANTENNA 1) with no matching.

Connections

• Transmitter: SO-239 connector for coax cable from transmitter or transceiver. There is a bias tee

connected to this connector so 12 volts DC can be sent down the coax to power the tuner for remote operation. A bias tee DC power injector, the MFJ-4116, is included with the MFJ-927.

• Antenna: SO-239 connector for coax cable from antenna. Notice the ANTENNA connector is internally connected to the WIRE binding post.

Note: To use the ANTENNA connector, make sure to remove the wire antenna, if any, from the

WIRE binding post.

• Ground: Wing-nut terminal for RF ground wire connection.

• Wire: Binding post for connecting single wire antennas. Notice the WIRE binding post is internally

connected to the ANTENNA connector.

Note: To use the WIRE binding post, make sure to remove the antenna, if any, from the

ANTENNA connector.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Installation

WARNING

● Never operate the tuner with its cover removed. Contact with the components inside the tuner while transmitting will result in painful RF burns.

● Locate the tuner so that the terminals are not accessible during operation. The single wire connection may have high voltage while transmitting.

● Disconnect all antennas from the tuner during lightning storms.

● Always tune with low power (about 10 watts). Apply maximum power only after tuning up.

● Never exceed tuner specifications.

● Do not transmit with a high SWR for extended periods of time.

1. Place the tuner in a convenient location at the operating position. We have provides mounting holes for versatile remote mounting options. With a random wire, the feed through insulators may 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 cannot accidentally be contacted during operation.

2. Install the Bias-Tee/Tuner combo between the transmitter and the antenna. Use a 50-ohm coaxial cable (such as RG-58) to connect the transmitter. See Figure 1.

3. Connect the transmitter to the “RF IN/OUT” coaxial connector on the MFJ-4116 Bias-Tee using a

50-ohm coaxial cable. (See Figure 1) This is the RF signal input connector.

4. Connect a 12-15 VDC voltage source capable of supplying at least 750 milli-amps to the “DC IN\OUT” jack on the MFJ-4116 Bias-Tee. This is your DC voltage input connector.

5. Connect the “RF/DC OUT/IN” coaxial connector on the MFJ-4116 Bias-Tee to the

TRANSMITTER connector on the MFJ-927 Intellituner using 50-ohm coaxial cable. The MFJ927 Intellituner will recover the RF and DC signals.

6. Connect your coax-fed antenna to the ANTENNA connector using a 50-ohm coaxial cable, or connect your random wire to the WIRE binding post.

7. Connect your ground connection to the GROUND post.

8. Key your transmitter to output a carrier of 10 watts CW, FM or AM. Using an external SWR/Wattmeter, check to ensure an SWR of 2.0 or less before increasing RF power.

9. You are ready to transmit.

• Random wire or single wire line antennas should be connected to the WIRE binding post on the

back of the tuner. Note the back panel warning: Do not connect WIRE and ANTENNA at

same time! When a single wire antenna is connected it “becomes” ANTENNA.

Note: Route all single and random wire antennas safely to prevent RF burn hazard.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Miscellaneous

Antenna Memory

The “memory resolution” is the width of frequency spectrum that the tuner recognizes as being the same as a tuned frequency already in memory. The memory resolution is approximately 0.1 percent of the lower frequency of each amateur band. For example, the memory resolution on the 40-meter band (7000 to 7300 kHz) is 7 kHz; if the tuner has memorized a setting for 7050 kHz, it will automatically call up this setting for any frequency from 7047 to 7053 kHz. Memory resolution is smaller at lower frequency to accommodate the higher antenna Q and larger at higher frequency where the antenna Q is lower. The memory resolutions for the HF amateur bands 160 through 10 meters are:

Meter Frequency Range (kHz) Memory Resolution (kHz)

160 1800 – 2000 2

75/80 3500 – 4000 4

60 5330.5, 5346.5, 5366.5, 5371.5 and 5403.5 5 memory locations 40 7000 – 7300 7 30 10100 – 10150 10 20 14000 – 14350 14 17 18068 – 18168 18 15 21000 – 21450 21 12 24890 – 24990 25 10 28000 – 29700 28

Table 1. Memory Resolution.

The memory resolution for non-amateur frequency bands between 160 and 10 meters is approximately

0.2 percent of the lower frequency of each band. There are over 2500 memory locations for each memory

bank, and each of the two antennas positions has four memory banks (A-D). Tuner settings are stored in memory separately for Antenna 1 and Antenna 2 (settings for single-wire antenna are stored as Antenna

1). This provides memory for up to eight different antennas. See “ANT Button” on page 5. Defaults are

memory banks 1A and 2A ON.

IntelliTuneTM Algorithm

When the tuner cannot find an appropriate setting in its memory, it begins its calculation function. It

measures the complex impedance of the antenna (load) at the transmitting frequency, then it calculates the LC components needed for a match. Then it fine-tunes the components for minimum SWR. If for any reason the tuner cannot calculate the load impedance, it proceeds to yet another method of calculation.

LC Limits

The upper limits of inductance (L) and capacitance (C) are factory-limited according to frequency and maximum power rating; i.e., higher frequencies need less inductance and less capacitance when the Lnetwork is properly tuned. These limits are built into the MFJ-927 to prevent matching of extreme load impedance outside the tuner’s specification, which may result in excess voltage and/or current across the tuner’s components.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Morse Code and Flashes

If not enough power is applied for tuning (less than two watts); “QRO” (dah-dah-di-dah di-dah-dit dahdah-dah) will be sent on CW. Increasing the input power above two watts ends this message.

When input power is too high, the tuner enters a self-protection mode. The tuner will not allow any of its relays to change. This feature is to prevent damage to your tuner.

If too much power is applied when tuning, the tuner will cease the tuning routine and send “QRP” (dahdah-di-dah di-dah-dit di-dah-dah-dit) on CW. This occurs when the forward power exceeds 75 watts and the SWR is greater than 3.0, or when the forward power exceeds 125 watts regardless of the SWR.

If more than 200 watts is applied to the tuner, the tuner will go into bypass mode and send “QRT” (dahdah-di-dah di-dah-dit dah) on CW.

If the tuning process is activated under these conditions, the tuner will not start the tuning. It will send the appropriate code on CW. The following table shows the various tuner Flashes:

Function

Antenna 1 2 [ANT] < 1

Memory Bank

Bypass Toggle

Tuned SWR

StickyTune

Tuning Mode Automatic Semi-Automatic [TUNE] +

Bank A

(1 Flash)

SWR ≤1.5

(1 Flash)

Indicates By

One Flash

Bank B

(2 Flashes)

Bypass Mode

(L = 0 and C = 0)

SWR ≤2.0

(2 Flashes)

On Off [TUNE] > 2

Table 2. Tuner Flashes.

Bank C

(3 Flashes)

SWR ≤2.5

(3 Flashes)

Indicates By Two Flashes

Bank D

(4 Flashes)

Restore Last L/C Setting [TUNE] < 0.5

SWR ≤3.0

(4 Flashes)

Off

(5 Flashes)

SWR >3.0

(“SWR”)

By Pressing

second

[ANT] > 1

second

sec.

[TUNE] for

0.5 to 2 seconds

seconds

[ANT]

Foldback Circuit

Modern transceivers with solid-state finals usually have a foldback circuit to protect the final transistors from high SWR, which can damage or destroy them. A foldback circuit detects the SWR during transmit and reduces the output power as the SWR rises above a preset threshold, usually 2:1. The higher the SWR the lower the power is set to prevent damage.

If your transceiver has a foldback circuit, you can simply key down and tune at any power level from 2 to 100 watts. If your transceiver does not have a foldback circuit, you must manually set the power level to 20 watts or less for tuning. At higher power levels, the reflected power occurred during tuning can damage your transceiver and causes component arcing which can damage the relays in the tuner.

Check your transceiver owner's manual to see if yours has a foldback circuit.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Grounding Hints

To minimize RFI, single wire feedlines (such as used with Windom or longwire antennas) should be kept away from other wiring. Radiation will be minimized if the single wire feeder runs parallel and reasonably close to the wire that connects the tuner to the outdoor ground. The antenna feed wire should be adequately insulated to prevent arcing or accidental contact.

CAUTION

For operator safety, a good outside earth ground or water pipe ground should always be installed and connected to the case of the MFJ-927. Make certain the safety ground also connects to the transmitter and other station accessories. A wing-nut post marked GROUND is provided for ground connections.

For safety, please use good DC and RF grounds. It is particularly important to have a good RF ground when using a single wire feeder. When using a single wire feeder, the tuner needs something to "push" against in order to force current into the single wire feedline. If a good RF ground is not available, RF will usually find its way back into the power line (RFI), transmitter audio circuits (RF feedback), or the operator (RF burns).

Metal water pipes and ground rods provide good DC and AC safety grounds, but they are often inadequate for RF grounding because they are single conductors. Ground rods by themselves are almost useless for dependable RF grounding.

RF grounds work much better when "spread out" over a large area, especially when they employ multiple connections directly to the equipment ground point. Metal water pipes, heating ducts, and fences may work (especially if they are connected together with multiple wires), but the best RF grounds are radial systems or multi-wire counterpoises. Radials and counterpoises provide large, low resistance surfaces for RF energy.

RF and lightning travel on the surface of conductors. Braided or woven conductors have high surface resistance to lightning and RF. Ground leads for RF and lightning should have wide smooth surfaces. Avoid the use of woven or braided conductors in RF and lightning grounds unless the lead needs to be flexible.

Antenna System Hints

Location

For the best performance, an end-fed longwire wire antenna should be at least one quarter-wavelength long at the operating frequency. Horizontal dipole antennas should be at least a half-wavelength long and located as high and clear as possible. While good RF grounds help the signal in almost any transmitting installation, it is extremely important to have good RF grounds with long wire or other Marconi-style antennas.

Matching Problems

Most matching problems occur when the antenna system presents an extremely high impedance to the

tuner. When the antenna impedance is much lower than the feedline impedance, an odd quarter-

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

wavelength feedline converts the low antenna impedance to a very high impedance at the tuner. A similar

problem occurs if the antenna has an extremely high impedance and the transmission line is a multiple of

a half-wavelength. The half-wavelength line repeats the very high antenna impedance at the tuner.

Incorrect feedline and antenna lengths can make an otherwise perfect antenna system very difficult or impossible to tune.

One example where this problem occurs is on 80 meters when an odd quarter-wave (60 to 70 feet) open wire line is used to feed a half-wave (100 to 140 feet) dipole. The odd quarter-wave line transforms the dipole's low impedance to over three thousand ohms at the tuner. This is because the mismatched

feedline is an odd multiple of 1/4 wavelength long. The line inverts (or teeter-totters) the antenna

impedance.

A problem also occurs on 40 meters with this same antenna example. The feedline is now a multiple of a half-wave (60 to 70 feet) and connects to a full-wave high impedance antenna (100 to 140 feet). The halfwave line repeats the high antenna impedance at the tuner. The antenna system looks like several thousand ohms at the tuner on 40 meters.

This places enormous strain on the balun and the insulation in the tuner, since voltages can reach several thousand volts. This can cause component arcing and heating.

The following suggestions will reduce the difficulty in matching an antenna with a tuner:

• Never center feed a half-wave multi-band antenna with a high impedance feedline that is close to an odd multiple of a quarter-wave long.

• Never center feed a full-wave antenna with a feedline close to a multiple of a half-wave long.

• If this tuner will not "tune" a multi-band antenna, add or subtract 1/8 wave of feedline (for the band

that won't tune) and try again.

• Never try to load a G5RV or center fed dipole on a band below the half-wave design frequency. If you want to operate an 80-meter antenna on 160 meters, feed either or both conductors as a longwire against the station ground.

To avoid problems matching or feeding any dipole antenna with high impedance open wire lines, keep the

lines around these lengths. [The worst possible line lengths are shown in brackets]:

160 meters dipole: 35-60, 170-195 or 210-235 feet [Avoid 130, 260 ft] 80 meters dipole: 34-40, 90-102 or 160-172 feet [Avoid 66, 135, 190 ft] 40 meters dipole: 42-52, 73-83, 112-123 or 145-155 feet [Avoid 32, 64, 96, 128 ft]

Some slight trimming or adding of feedline may be necessary to accommodate the higher bands.

WARNING

To avoid problems, a dipole antenna should be a full half-wave on the lowest band. On 160 meters, an 80 or 40 meters antenna fed the normal way will be extremely reactive, with only a few ohms of feedpoint resistance. Trying to load an 80 meters half-wave dipole (or shorter) antenna on 160 meters can be a disaster for both your signal and the tuner. The best way to operate 160 meters with an 80 or 40 meters antenna is to load either or both feedline wires (in parallel) as a longwire. The antenna will act like a “T” antenna worked against station ground.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Appendices

POWER-ON OPERATIONS

(Press and hold buttons while turning on the power.)

Press and hold + to start the self test. Press and hold + + to delete current antenna memory. Press and hold + the n press 1 time to reset factory defaults. Press and hold + the n press 2 times to delete current memory ba nk. Press and hold + the n press 3 times to perform total reset. Press and hold + then press 4 times to test the power-down circuitry. Press and hold + then press 5 times to test the relays. Press and hold + then press 6 times to calibrate the frequency counter. Press and hold + the n press 7 times to calibrate the SWR bridge.

For the + operations, not pressing or pressing it more than seven times will cancel the operation after idling four seconds, beep two times and then resume normal operation.

ANT ANT ANT TUNE ANT TUNE ANT TUNE ANT TUNE

POWERANT

POWER POWER POWER POWER POWER POWER POWERANT TUNE

POWERTUNE POWERANTTUNE

TUNE TUNE

UNE

Figure 2. Power-On Operations.

Resetting the Tuner

Each time the tuner is powered off, the microprocessor saves all memories and configurations to nonvolatile memory ready to be used the next time the unit is turned on again. If the tuner is not working properly, even on initial power on, try resetting to the factory defaults.

Factory Defaults

The unit is shipped with the following default settings:

• Inductance 0 μH

• Capacitance 0 pF on antenna side

• Antenna 1

• Memory Banks 1A and 2A

• Tuning Mode Automatic

Note: Resetting to factory defaults does not erase the antenna memories.

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MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

To reset the tuner to these defaults:

1. Turn off the power to the tuner.

2. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

3. Within four seconds of releasing [ANT], press the [TUNE] button once.

4. After releasing [TUNE] for four seconds, Flash three times and resume normal operation.

WARNING: If the MFJ-927 is behaving weirdly or acting erratic, try resetting the tuner to

factory defaults.

Delete Entire Antenna Memory

To delete an entire antenna memory (all four banks), first select the antenna (1 or 2) that you want to delete. See “ANT Button” on page 5 for details.

1. Turn off the power to the tuner.

2. Press and hold both the [TUNE] and [ANT] buttons while turning the power on. It takes

approximately three seconds to delete all four memory banks of the current antenna.

3. Flash three times and release the buttons to resume normal operation. Remember that the

selected antenna memory will be lost!

Delete Antenna Memory Bank

To delete an antenna memory bank, first select the antenna (1 or 2) and the memory bank (A, B, C or D) that you want to delete. See “ANT Button” on page 5 for details.

1. Turn off the power to the tuner.

2. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

3. Within four seconds of releasing [ANT], press the [TUNE] button two

4. After releasing [TUNE] for four seconds, the current memory bank is deleted.

5. Flash three times and resume normal operation. Remember that the selected antenna memory

bank will be lost! However, if the memory is off, no memory bank is deleted; then Flash two times and resume normal operation.

6. Repeat the above procedure to delete the other memory banks, if desired.

Total Reset

To erase both antenna memories (all eight banks) and reset to factory defaults:

1. Turn off the power to the tuner.

2. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

3. Within four seconds of releasing [ANT], press the [TUNE] button three

4. After releasing [TUNE] for four seconds, both antenna memories are deleted and factory defaults

are reset. The total reset takes approximately six seconds.

5. Flash three times and resume normal operation. Remember that both antenna memories will be

lost!

times.

Page 17

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Self Test

A self-test routine will check the functions of the MFJ-927. This routine checks the LEDs, the frontpanel buttons, the internal memory, the audio circuitry, and the power-down circuitry. During the selftest, you may stop the test by turning off the unit; however, this should NOT be done during the memory test or the memory could be corrupted. The self-test can be completed in approximately 10 seconds.

Note: Performing the self-test will reset the unit to its factory default settings.

Here is the self-test procedure:

1. Turn off the power to the tuner.

2. Unplug the radio interface cable, if one is connected, from the tuner.

3. Press and hold only the [TUNE] button while turning the power on.

4. The test begins by blinking the firmware version number via the two front panel LEDs. The

green LED blinks first, followed by the red LED. The version number X.Y is represented by the number of times the green LED blinks for X and the number of times the red LED blinks for Y. For example, green LED blinks one time and red LED blinks two times represent firmware version number 1.2. This is also the test of the LEDs.

5. Release the [TUNE] button. The unit then checks for short circuits, power-down detection level,

and wakeup circuitry.

6. Press [ANT] button and the green LED should blink once.

7. Press [TUNE] button and the green LED should blink once.

8. The unit then tests its non-volatile memory. Notice this step will reset the unit to its factory

default settings.

9. If the unit is okay, a repetitive message “PASS” will be sent as Morse code (di-dah-dah-dit di-dah

di-di-dit di-di-dit) and the green LED will blink. If there is a problem, a failure message will be sent repetitively and the red LED will blink.

10. Once you have confirmed that the audio is okay, turn the unit off.

11. Wait one second and turn the unit on again to test the power-down detection circuitry.

12. If the power-down detection circuitry is okay, a repetitive message “PASS” will be sent as Morse

code (di-dah-dah-dit di-dah di-di-dit di-di-dit) and the green LED will blink. If there is a problem, message “PD FAIL” will be sent as Morse code repetitively and the red LED will blink.

13. Turn the power off.

Failure

Message

ANT FAIL [ANT] button is shorted or improperly connected.

TUNE FAIL [TUNE] button is shorted or improperly connected.

MEMORY FAIL Non-volatile memory circuitry is improperly connected.

WAKEUP FAIL Microprocessor wakeup circuitry problem.

PD FAIL Power-down circuitry problem.

Table 3. Failure Messages.

Indicates

Page 18

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Power-Down Circuit Test

When the 12 VDC power to the tuner is turned off, the tuner saves all settings to non-volatile memory. The Power-Down Circuit Test checks the power-down detection circuitry. It is recommended that this test be done immediately after the regular self-test described above.

Note: The tuner must be reset to factory defaults before performing this test.

Here is the test procedure:

1. Make sure power to the tuner is off.

2. If the tuner has been reset to factory defaults, skip to step 6; otherwise continue with step 3.

3. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

4. Within four seconds of releasing [ANT], press the [TUNE] button once.

5. After releasing [TUNE] for four seconds, Flash three times and turn the power off.

6. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

7. Within four seconds of releasing [ANT], press the [TUNE] button four

times.

8. After releasing [TUNE] for four seconds and if the power-down detection circuitry is okay, a

repetitive message “PASS” will be sent as Morse code (di-dah-dah-dit di-dah di-di-dit di-di-dit) and the green LED will blink. If there is a problem, message “PD FAIL” will be sent as Morse code repetitively and the red LED will blink.

9. Turn the power off.

Relay Test

WARNING: Turn off the transmitter power or disconnect the transmitter before performing

this test; otherwise, damage to the tuner can result.

To test the relays and their control circuitry;

1. Turn off the power to the tuner.

2. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

3. Within four seconds of releasing [ANT], press the [TUNE] button five

times.

4. After releasing [TUNE] for four seconds, Flash once and the Relay Test routine is initiated.

5. Press the [TUNE] button to engage the relay and the red LED will turn on. Release the [TUNE]

button to disengage the relay and the red LED will turn off. Listen for relay clicks.

6. There are 19 relays in the tuner. Press the [ANT] button to test the next relay. The green LED

will illuminate until the [ANT] button is released.

7. Repeat Steps 5 and 6 to test all 19 relays (in the order of relay K1 to K19).

8. After releasing [ANT] on the 19

relay, Flash three times and resume normal operation.

Page 19

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Frequency Counter Calibration

To calibrate the frequency counter, you will need a transmitter, a 50-ohm dummy load, two 50-ohm SO239 coax cables, a Phillips screwdriver, and a tuning tool or small flat blade screwdriver.

WARNING: Do not touch anything inside the tuner during operation! Serious, painful RF

burns can result.

WARNING: Never operate the MFJ-927 with its cover removed; dangerous voltages and

currents can be present during operation. Never exceed tuner specifications.

1. Turn off the power to the transmitter and the tuner.

2. Remove the cover from the tuner (6 screws) with a Phillips screwdriver.

3. Connect the transmitter to the “RF IN/OUT” coaxial connector on the MFJ-4116 Bias-Tee

using a 50-ohm coaxial cable. (See Figure 1) This is the RF signal input connector.

4. Connect a 12-15 VDC voltage source capable of supplying at least 750 milli-amps to the “DC

IN\OUT” jack on the MFJ-4116 Bias-Tee. This is your DC voltage input connector.

5. Connect the “RF/DC OUT/IN” coaxial connector on the MFJ-4116 Bias-Tee to the

TRANSMITTER connector on the MFJ-927 Intellituner using 50-ohm coaxial cable. The MFJ-927 Intellituner will recover the RF and DC signals.

6. Connect a 50-ohm dummy load to the ANTENNA connector using a 50-ohm coaxial cable.

7. Turn on the power to the transmitter. Set and lock the frequency to exactly 29.000 MHz.

8. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

9. Within four seconds of releasing [ANT], press the [TUNE] button six

times.

10. After releasing [TUNE] for four seconds, the green LED lights up and the Frequency Counter

Calibration is initiated.

11. Key the transmitter to output about 10 watts and adjust trimmer capacitor VC3 (located next to

the big integrated circuit on the front side of the front panel circuit board) until both LEDs are lighted up. The green LED lights when the calibration is below 29 MHz, the red LED lights when the calibration is above 29 MHz and both LEDs light up when the calibration equals to 29 MHz.

12. Unkey the transmitter. Turn off the power to the transmitter and the tuner.

13. Secure the cover back onto the tuner.

SWR Bridge Calibration

To calibrate the SWR Bridge, you will need a transmitter capable of 100 watts output, a precise calibrated wattmeter, a 50-ohm dummy load, three 50-ohm SO-239 coax cables, a Phillips screwdriver, a tuning tool or small flat blade screwdriver, and a cross-needle wattmeter (available only at MFJ factory). Therefore, this calibration can only be done at MFJ factory.

WARNING: Do not touch anything inside the tuner during operation! Serious, painful RF

burns can result.

WARNING: Never operate the MFJ-927 with its cover removed; dangerous voltages and

currents can be present during operation. Never exceed tuner specifications.

Page 20

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

1. Turn off the power to the transmitter and the tuner.

2. Remove the cover from the tuner (6 screws) with a Phillips screwdriver.

3. Connect the cross-needle wattmeter to header HD1, located behind the front panel circuit board.

4. Connect the transmitter to the “RF IN/OUT” coaxial connector on the MFJ-4116 Bias-Tee

using a 50-ohm coaxial cable. (See Figure 1) This is the RF signal input connector.

5. Connect a 12-15 VDC voltage source capable of supplying at least 750 milli-amps to the “DC

IN\OUT” jack on the MFJ-4116 Bias-Tee. This is your DC voltage input connector.

6. Connect the “RF/DC OUT/IN” coaxial connector on the MFJ-4116 Bias-Tee to the

TRANSMITTER connector on the MFJ-927 Intellituner using 50-ohm coaxial cable. The MFJ-927 Intellituner will recover the RF and DC signals.

7. Connect a 50-ohm dummy load to the ANTENNA connector using a 50-ohm coaxial cable.

8. Turn on the power to the transmitter. Using a frequency in the middle of the HF band, such as

7.253 MHz, for calibration is recommended.

9. Press and hold only the [ANT] button while turning the power on. Both LEDs will blink until the

button is released.

10. Within four seconds of releasing [ANT], press the [TUNE] button seven

11. After releasing [TUNE] for four seconds, the cross-needle wattmeter shows 100 watts forward

and 20 watts reflected and the SWR Bridge Calibration is initiated.

12. Make sure the cross-needle wattmeter reads 100 watts forward and 20 watts reflected. If not,

calibrate the cross-needle wattmeter.

13. Press the [TUNE] button and both meter needles drop to 0 watt marks.

14. Key the transmitter to output 100 watts and adjust trimmer capacitor VC1 (located in front of the

TRANSMITTER connector) for minimum reflected power. Notice the reflected meter movement is exaggerated for easier calibration.

15. Key the transmitter to output 100 watts and adjust the FWD trimpot VR1 until the forward meter

shows 100 watts.

16. Press the [TUNE] button and the reflected meter goes to full scale.

17. Turn off the transmitter and reverse the ANTENNA and TRANSMITTER connections.

18. Turn on the transmitter’s power.

19. Key the transmitter to output 100 watts and adjust the REF trimpot VR2 until the forward meter

(yes, the forward meter) shows 100 watts; the reflected meter is at full scale.

20. Press the [TUNE] button to end calibration.

21. Turn off the power to the transmitter and the tuner.

22. Remove the cross-needle wattmeter from header HD1.

23. Remove the transmitter/wattmeter and the 50-ohm dummy load from the tuner.

24. Secure the cover back onto the tuner.

times.

In Case of Difficulty

If the LCD screen is blank, check adjustment of the contrast control. If no audio is present (with audio enabled) adjust the volume control.

If the tuner acts erratic, reset the tuner to factory defaults by pressing both the [TUNE] and [L-UP] buttons while turning the power on.

If the tuner fails to tune, please double check all connections and follow the tuning procedures again. Be sure you are using enough inductance (through manual adjustment) and minimum capacitance.

Page 21

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

If the tuner arcs at the rated power levels, please double check all connections and follow the tuning

procedures again. Ensure you are not exceeding the tuner’s rated power handling capability. Be sure you

are using the least amount of inductance and the greatest capacitance possible that still allows matching

the load on the operating frequency.

Note: If the tuner arcs when operating on the 160-meter band, it may be necessary to reduce

transmitter output power.

If you are still unsuccessful, but the tuner does adjust and operate when used with a dummy load or another antenna, please read “Grounding Hints” and “Antenna System Hints” on page 13.

Technical Assistance

If you have any problem with this unit first check the appropriate section of this manual. If the manual

does not reference your problem or your problem is not solved by reading the manual, you may call MFJ Technical Service at 662-323-0549 or the MFJ Factory at 662-323-5869. You will be best helped if you

have your unit, manual and all information on your station handy so you can answer any questions the technicians may ask.

You can also send questions by mail to MFJ Enterprises, Inc., 300 Industrial Park Road, Starkville, MS 39759; by facsimile (FAX) to 662-323-6551; or by email to techinfo@mfjenterprises.com. Send a complete description of your problem, an explanation of exactly how you are using your unit, and a complete description of your station. Also include the firmware version number of your unit.

List of Accessories

• MFJ-1316: 12 VDC 1.5 amp power supply

• MFJ-4116: BiasTee DC power injector

• MFJ-5114A: Interface cable for compatible Alinco radios

• MFJ-5114I: Interface cable for compatible Icom radios

• MFJ-5114K: Interface cable for compatible Kenwood radios

• MFJ-5114Y: Interface cable for Yaesu FT-100, FT-817, FT-857 and FT-897 (CAT)

• MFJ-5114Y2: Interface cable for Yaesu FT-847 (CAT)

• MFJ-5124Y3: Interface cable for Yaesu FT-857 and FT-897 (TUNER)

• MFJ-5409: 6 feet long RS-232 cable, female DB-9 to male DB9 connector

• MFJ-5803: 3 feet long RG-58 A/U 50-ohm coax cable with a PL-259 connector on each end

• MFJ-5806: 6 feet long RG-58 A/U 50-ohm coax cable with a PL-259 connector on each end

• MFJ-5818: 18 feet long RG-58 A/U 50-ohm coax cable with a PL-259 connector on each end

Page 22

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

Page 23

MFJ-927 Remote IntelliTuner Automatic Antenna Tuner Instruction Manual

FULL 12-MONTH WARRANTY

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.

1. The purchaser must retain the dated proof-of-purchase (bill of sale, canceled check, credit

card or money order receipt, etc.) describing the product to establish the validity of the warranty claim and submit the original or machine reproduction of such proof of purchase to MFJ Enterprises, Inc. at the time of warranty service. MFJ Enterprises, Inc. shall have the discretion to deny warranty without dated proof-of-purchase. Any evidence of alteration, erasure, of forgery shall be cause to void any and all warranty terms immediately.

2. MFJ Enterprises, Inc. agrees to repair or replace at MFJ's option without charge to the

original owner any defective product provided the product is returned postage prepaid to MFJ

Enterprises, Inc. with a personal check, cashiers check, or money order for $10.00 covering

postage and handling.

3. MFJ Enterprises, Inc. will supply replacement parts free of charge for any MFJ product under warranty upon request. A dated proof of purchase and a $8.00 personal check, cashiers

check, or money order must be provided to cover postage and handling.

4. This warranty is NOT void for owners who attempt to repair defective units. Technical

consultation is available by calling (662) 323-5869.

5. This warranty does not apply to kits sold by or manufactured by MFJ Enterprises, Inc.

6. Wired and tested PC board products are covered by this warranty provided only the wired and tested PC board product is returned. Wired and tested PC boards installed in the

owner's cabinet or connected to switches, jacks, or cables, etc. sent to MFJ Enterprises, Inc. will be returned at the owner's expense unrepaired.

7. Under no circumstances is MFJ Enterprises, Inc. liable for consequential damages to

person or property by the use of any MFJ products.

8. Out-of-Warranty Service: MFJ Enterprises, Inc. will repair any out-of-warranty product

provided the unit is shipped prepaid. All repaired units will be shipped COD to the owner. Repair charges will be added to the COD fee unless other arrangements are made.

9. This warranty is given in lieu of any other warranty expressed or implied.

10. MFJ Enterprises, Inc. reserves the right to make changes or improvements in design or

manufacture without incurring any obligation to install such changes upon any of the products previously manufactured.

11. All MFJ products to be serviced in-warranty or out-of-warranty should be addressed to MFJ Enterprises, Inc., 300 Industrial Park Rd, Starkville, Mississippi 39759, USA and must

be accompanied by a letter describing the problem in detail along with a copy of your dated proofof-purchase and a telephone number.

12. This warranty gives you specific rights, and you may also have other rights, which vary

from state to state.

Page 24

300 Industrial Park Road Starkville, MS 39759

MFJ-927 Manual

Vers io n 1A

Printed In U.S.A.

MFJ MFJ-927 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual