MFJ-931_Manual操作说明书手册

MFJ-931 Instruction ManualArtificial RF GroundMFJ ARTIFICIAL GROUNDIMPORTANT:Please read entire manual before attempting to operate thisequipment.This unit does not provide a DC electric ground.Aseparate wire will need to be run from the transmitter to anelectric ground if it is not already available.Thank you for purchasing the MFJ-931 ARTIFICIAL GROUND.The MFJ-931 creates anartificial ground with a random length of wire thrown on the floor.This produces a tunedcounterpoise.Also,the MFJ-931 will electrically place a far away RF ground directly at our rig.INSTALLATION AND OPERATIONCreating Artificial GroundConnect your transmitter ofantenna tuner to the binding post labeled "To Transmitter orAntenna Tuner Chassis Ground"on the back of the MFJ-931Note:This wire needs to be as short as possible,preferably with the ground posts as close aspossible i.e.,the units side by side or one on top of the other.Attach the length of random wire to the red binding post labeled "To Counterpoise Wire orGround Connection Wire"on back of the MFJ-931.Be sure not to reverse these wires.Therandom wire should be a quarter-wave length or less at the operating frequency.Be sure tothrow the random wire along the floor and to tape up the open end of the wire to avoid RFburn.To obtain maximum RF ground current for a low impedance RF ground,alternately adjust thetwo controls on the front panel labeled "INDUCTANCE"and "CAPACITANCE".Turn theDANGER:Touching the wire while keying can cause RF burn and ispotentially fatal.Watch out for children and pets.INDUCTANCE control first until the highest amount of current can be registered on the built-inAMMETER.Then adjust the CAPACITANCE control to increase the amount of RF current.Try several inductance setting for best results.What if the needle goes off the scale or doesn'tmove at all?Then the sensitivity of the Ammeter needs to be adjusted.Turn the SENSITIVITYcontrol until the needle is in the middle of the scale.Then readjust the INDUCTANCE controlfor the highest amount of RF current and use the CAPACITANCE control to achievemaximum RF current.If the needle is still off scale or zero,readjust the SENSITIVITY controland repeat the tuning process