MFJ Legal Limit IntelliTuner MFJ-998RT, Instruction Manual

Page 1: ...tic Antenna Tuner MFJ 998RT 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 Version 1A 2011 MFJ Enterprises Inc ...

Page 2: ...ENUS 9 Main Mode Menus 9 Digital Wattmeter Menu 9 Power Bar Meter Menu 9 L Network Menu 10 Tuner Indicators 10 Setup Mode Menus 13 Target SWR Menu 13 Auto Tune SWR Menu 13 Amp Bypass SWR Menu 13 Meter Range Menu 13 Peak Hold Menu 13 Memory Menu 13 IntelliTune TM Menu 14 SWR Beep Menu 14 Beep Menu 14 Refresh Menu 14 Radio Interface Menu 15 LC Limit Menu 15 Setup Operation 15 Manual Tuning 15 Morse ...

Page 3: ... Frequency Counter Calibration 22 List of Accessories 23 FULL 12 MONTH WARRANTY 24 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 curre...

Page 4: ... ranges are 0 to 24 µH and 0 to 3900 pF And once a match is found the matching network values can be displayed so you may design your own fixed matching network if desired Like all MFJ IntelliTuners TM the MFJ 998RT learns and remembers When you transmit it automatically adjusts for minimum SWR and remembers the frequency and tuner settings safely stored in non volatile memory The next time you op...

Page 5: ... out of matching L C values available after tuning for testing and setup Specifications Impedance matching range 12 to 1600 ohms SWR matching range up to 4 1 for 50 ohms and up to 32 1 for 50 ohms Minimum power for tuning 5 watts Maximum power while tuning 100 watts with foldback 20 watts without foldback RF power limit 1500 watts SSB CW Frequency range 1 8 to 30 MHz continuous coverage Frequency ...

Page 6: ... output to the MFJ 4117 BIAS TEE RF connector using a 50 ohm coaxial cable 2 Connect the MFJ 4117 BIAS TEE to a 12 15 VDC voltage source capable of supplying at least 1 4 amps The center pin on the power connector is positive 3 Connect the MFJ 4117 BIAS TEE RF DC output to the TRANSMITTER connector on the MFJ 998RT 4 Connect your coax fed antenna to the ANTENNA connector using a 50 ohm coaxial cab...

Page 7: ... power levels expected See Figure 1 on page 4 3 Connect the antenna s to the tuner as follows 4 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 Both are connected in parallel Note Route all single and random wire antennas safely to prevent RF burn hazard For balan...

Page 8: ... settings for that frequency if memorized and quickly tune to those settings c If the frequency is not memorized or the SWR is outside the tuning window then the tuner will retune as in the initial tuneup 4 Once the tuner is tuned up you can switch to high power operation 5 Manual tuning is possible but is not available remotely To tune manually you will have to remove the cover and operate the co...

Page 9: ... of short beeps where one beep indicates bank A two beeps indicate bank B three beeps indicate bank C four beeps indicate bank D and five beeps indicate antenna memory is OFF The Memory indicator on the main display also indicates the selected bank Pressing the ANT button switches the antenna bank or memory bank only when there is no RF power Also the tuner setting for the selected antenna bank or...

Page 10: ...automatic tuning mode In automatic mode the tuning routine is automatically started when at least five watts of power is applied and the SWR is a preset amount above the preset target SWR In semi automatic mode the tuning routine starts only when the TUNE button is pressed for 0 5 to 2 seconds The Auto Semi indicator on the main display indicates the selected mode Refer to Figures 15 and 16 for th...

Page 11: ...MFJ 998RT Legal Limit IntelliTunerTM Automatic Remote Antenna Tuner Instruction Manual 2011 MFJ Enterprises Inc MFJ 998RT Version 1A 8 Figure 2 Mode Button Flow Chart ...

Page 12: ...equency SWR forward power and bar meters for forward and reflected power The top bar meter is the forward power and the bottom bar meter is the reflected power The numeric reading of forward power appears at the end of the bar meters Each power bar meter is consisted of 60 bar segments When in the high power range multiple the readings on the printed power scale by ten and each vertical bar segmen...

Page 13: ...ge 14 Tuner Indicators Various tuner indicators are shown on the main menus to indicate tuner status Refer to Figures 6 and 7 for locations of these indicators The number enclosed within is the item number of Figure 7 Antenna Bank A small 1 appears to indicate antenna bank 1 is selected 15 a small 2 appears to indicate antenna bank 2 is selected 16 Radio Interface One dot appears on the left side ...

Page 14: ...MFJ 998RT Legal Limit IntelliTunerTM Automatic Remote Antenna Tuner Instruction Manual 2011 MFJ Enterprises Inc MFJ 998RT Version 1A 11 Figure 6 LCD Display ...

Page 15: ...MFJ 998RT Legal Limit IntelliTunerTM Automatic Remote Antenna Tuner Instruction Manual 2011 MFJ Enterprises Inc MFJ 998RT Version 1A 12 Figure 7 Display Tuner Indicators Enlarged ...

Page 16: ...f the setting for the current setup menu Target SWR Menu Allows you to set the target SWR from 1 0 to 2 0 The tuning process will stop when a match with an SWR less than or equal to the target SWR is found Setting the target SWR lower than 1 5 may require longer tuning times The target SWR is shown on the initial display when the tuner is powered on Default is 1 5 Auto Tune SWR Menu Allows you to ...

Page 17: ...ieve this turn power off press and hold TUNE C UP and L UP buttons while turning on the power A TOTAL RESET message will appear Note Pressing TUNE C DN and L DN buttons simultaneously overwrites the tuner memory with the current tuner setting settings with SWR greater than 3 0 will not be stored IntelliTune TM Menu Turns the IntelliTune TM tuning algorithm on and off When the tuner cannot find an ...

Page 18: ...ess than 20 watts conditions In certain cases the operator may wish to touch up the tuner s settings For example if the target SWR is set at the default of 1 5 the tuner will stop when a match of 1 5 is found Changing frequencies may raise the SWR but still be within the SWR retune window Manual tuning gives the user control of the tuner if desired and the L Network menu provides a picture of the ...

Page 19: ...de on CW The following table shows the various tuner beeps Function Indicates By One Beep Indicates By Two Beeps By Pressing Antenna Bank 1 2 ANT 1 second Memory Bank A 1 Beep B 2 Beeps C 3 Beeps D 4 Beeps OFF 5 Beeps ANT 1 second Bypass Toggle Bypass Mode L 0 and C 0 Restore Last L C Setting TUNE 0 5 seconds or C DN L DN Tuned SWR SWR 1 5 1 Beep SWR 2 0 2 Beeps SWR 2 5 3 Beeps SWR 3 0 4 Beeps SWR...

Page 20: ...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 lightni...

Page 21: ...y 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 4...

Page 22: ...mit power is applied 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 Main Menu Digital Wattmeter Setup Menu Target SWR Inductance 0 µH Capacitance 0 pF Antenna 1 Tuning Mode Automatic Target SWR 1 5 Auto Tune SWR 0 5 above target SWR Amp Bypass SWR 2 0 Meter Range Auto range...

Page 23: ...g the power back on A confirmation message DELETE ANTENNA will display Press the YES C DN button to delete the antenna memory a progress bar and DELETED will display or press the NO L DN button to cancel CANCEL will display Release the button to resume normal operation Remember that the selected antenna memory will be lost Delete Antenna Memory Bank To delete an antenna memory bank select Antenna ...

Page 24: ...rly connected L DN FAIL L DN shorted or improperly connected TUNE FAIL TUNE 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 Figure 11 Failure Messages Power Down Circuit Test When the 12 VDC power to the tuner is turned off the tuner saves all settings to non v...

Page 25: ...ter Using a frequency in the middle of the HF band such as 7 253 MHz for calibration is recommended 5 Press and hold both the C UP and L UP buttons while turning the tuner power on 6 A message CAL CAP AND FWD will display Key the transmitter to output 100 watts and adjust trimmer capacitor VC1 located on the small circuit board mounted in front of the TRANSMITTER connector for minimum reflected po...

Page 26: ...ull scale and a message CAL FREQ 29 000 will display 6 Key the transmitter to output about 10 watts Adjust trimmer capacitor VC2 located next to the big integrated circuit until the tuner displays a frequency of 29 000MHz and the meter needles settle at the 0 watt marks Notice the meter movement is exaggerated for easier calibration Nominal tolerance of the frequency counter is 1 kHz 7 Turn off th...

Page 27: ... 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 prod...

Page 28: ...MFJ 998RT Manual Version 1A Printed In U S A 09 2011 MFJ ENTERPRISES INC 300 Industrial Park Road Starkville MS 39759 ...