HY-GAIN--TH-3MK4-3BD ANT.pdf

Select each completed element assembly and installeach into the appropriate element-to-boombracket. Refer to the Overall View in Figure 8.Tighten the eight (8) 1/4"-20 x 3/4" bolts on eachbracket until it is difficult to rotate the bracket onthe boom. Make sure the anchor bolts in the centerof each bracket are still loose at this point.Recheck the spacings between the elements andadjust if necessary. Align all three elements sothat they are parallel to the ground and at a rightangle to the temporary mast. When all elementsare aligned, securely tighten the eight bolts andtwo anchor bolts on each element. All trap drainholes must be facing the ground at this point!Beta MatchSelect the beta match rods (Item 9), beta matchclamps (Item 2), and#10-24 hardware. Assembleas shown in Figure 9.Balun ChoicesThe T113-MK4 does not include a balun,however it is recommended that a balun orcoaxial RF choke be used at the feedpoint. Avoltage-balun such as the Hy-Gain BN-86 maybe used if antenna tuners and high-poweramplifiers will not be used together with thisantenna.A current-type balun such as the Hy-Gain BN-4000 is highly recommended, especially if thisantenna will be used off-resonance with antennatuners and high-power amplifiers. Another alternativeis to use a home-made RF choke. Thisworks identical to the current-type balun. The RFchoke may be wound from 12 turns of RG-213/Uon a 6 inch diameter form. One end should bestripped as shown in Figure 10. The RF chokeMUST be mounted at the driven element.InstallationDouble-check all dimensions and tighten all connectionsbefore installation. Ensure that all trapdrain holes will be facing the ground.WARNING!Installation of this antenna near power linesis dangerous! For your safety, follow theinstructions provided with your tower andthe instructions in this manual. NEVERinstall this antenna within 20 feet of anypower lines!The cast aluminum boom-to-mast brackets mustbe removed from the temporary mast andinstalled on the permanent mast as shown inFigure 1. Attach a gin pole to the tower or mast toassist in lifting the antenna. There must be at leasttwo (2) people available when installing thisantenna. DO NOT try to install this antenna byyourself!