Trap Dipole Antenna INSTRUCTION MANUAL - …

1 ORDER NO. 380 SModel 2 BDQ-STrap Dipole AntennaINSTRUCTION MANUALG eneral DescriptionConstructionThe Hy-Gain Model 2 BDQ-S is a 1/2wavelength, Dipole Antenna for 40 and 80meters. Band switching is accomplishedautomatically through the use of two matchedHy-Gain 40-meter Hy-Q traps. The maximumoverall length is 100' 10 1/2". If the antennais mounted in an inverted "V" configuration,the overall length will be balun will improve the performance andefficiency of the 2 BDQ-S. The Hv-GainModel BN-86 is a broadband balun designedspecifically for Dipole -type antennas. Thebalun balances the input impedance to theantenna and prevents transmission Hy-Q traps will withstand hard wear andsevere weather conditions.

2 All hardware ispassivated stainless steel. The center of thedipole is supported with a yoke-type centerinsulator to which the transmission lineattaches. The ends of the Dipole are supportedby two end insulators constructed of highimpact ABS plastic. The Antenna wire isAlumoweld #12, which resists rust and hasa breaking strength of 1200 and FeedlineThe 2 BDQ-S Antenna is designed for use withsingle 50 ohm coaxial feedline. The SWR atresonance is :1 or less on both or RG213/U is of OperationMatched Hy-Gain Hy-Q traps give true 1/2-wave resonance. They are tuned at the factoryand no adjustments are necessary.

3 Theyoperate as a high impedance circuit on 40meters and add to the overall length of theantenna as center loading for the 80/75 is a registered trademark of CopperweldBimetallic GroupAssembly ProcedureReferring to Figure 1, place one half of thecenter insulator (Item ) on a flat surfacewith the inside facing the hardware on the eyebolts andplace in the 1 Assembly of Antenna Wire to CenterInsulatorStrip the coax and separate the center conduc-tor from the braid. Solder the braid to onesolder lug (Item No. 22) and the centerconductor to the other solder lug. For asmaller coax, a reducing sleeve is silicone grease or Vaseline , etc.

4 (notsupplied) to the mating the halves together and secure themusing the #6-32 x 3/8" bolts and nuts (ItemNos. 15 & 16).Hold the eyebolt to keep it from turning andtighten the 1/4" nuts on the outside, first oneside and the : Both sides of the Antenna are exactlythe same. Each of the following steps must bedone first for one side then repeated for theother the 40-meter wire (LI) to either Phone orContinuous Wave (CW) dimensions as shownin Figures 2 and 3. Add an extra three incheson each end for attaching to the centerinsulator and 40-meter trap. Example: Lllength for CW operation is 19' 8 1/4". Addsix inches, three inches each end, whichmakes a total length of 20' 2 1/4".

5 Eachinsulator or trap requires three inches forproper one end of the wire (just cut) to thecenter insulator (Item ) using the wirelocks as shown in Figure 1. Do not forget toconnect the pigtail to the wire off all excess wire extending past thewire the 40-meter trap and the trapconnector clamps. Assemble the clamps onboth ends of the trap using the #10-24 x 11/2" bolts, lockwashers, and nuts (Item , 11, and 10), as shown in Figure remeasure the Antenna wire con-nected to the center insulator and bend thewire for attachment to the 40-meter trap asshown in Figures 2 and the wire to the trap using the wirelocks (Item No.)

6 5) and shown in Figure off all excess wire extending past thewire : When you have selected your mode oftransmission (Phone or CW), you must use thesame mode for all 2 Antenna WireMeasurementsVaselincis a registered trademark of Chesebrough -Ponds,NOTE: The end of the trap which has a small bolt must bepointed in the direction of the center insulator as shown inFigures 3 and 4. This is very important for proper operationof the only one bolt on the side of the clamp opposite thedrain holes. An off-center wire attachment is used to keepthe drain holes downward. Remove the twists and kinksfrom the wire prior to the installation to insure that the trapsdo not rotate in the final mounting , Trap Connector13 Nut, hex, #8-325 Wire Lock14 Lockwasher, internal, #89 Bolt, hex head, #10-24 x 1 1/2"17 Bolt, hex head, 1/4"-20 x10 Nut, hex, #10-2419 Nut, hex, 1/4"-2011 Lockwasher, internal, #1020 Lockwasher, internal 1/4"12 Bolt, round head, #8-32 x 112"Figure 4 Assembly of the Antenna Wireto the TrapsCut the 80-meter Antenna wire (L2) to thelength shown for your mode of transmission(Phone or CW).

7 Do not forget to allow anextra three inches on each end for attachmentto the 40-meter trap and end one end of the wire and attach to the40meter trap as shown in Figures 2 and 4. Donot forget to clip off the excess wireextending past the wire remeasure wire and bend for attach-ment to the end the wire to the end insulator as shownin Figure 5. Clip off all excess wire extendingpast the wire Description1 Wire, Antenna , Alumoweld #12 by 100 , End5 Wire Lock12 Bolt, round head, #8-32 x 1/2"Figure 5 Assembly of the Antenna Wire to the End InsulatorMountingThe Antenna is now ready to be mounted ineither the horizontal or inverted "V"configuration.

8 Refer to Figures 6 and 7 forproper dimensions. When suspending the endinsulators, non-metallic line is preferred. Ifyou do use ire, it must be broken up everysix feet with strain insulators to preventharmful effects to your radiation the Antenna by attaching the end in-sulators to a stable structure. The center in-sulator may be supported by the Antenna itselfor suspended from a support. Whensuspending the center insulator from asupport, be sure to keep the insulator fromcontacting any of the supporting structure. Forproper operation of this Antenna , the centerinsulator should be about 46 feet above theground.

9 The higher the Antenna , the better 6 HorizontalMountingFigure 7 Inverted "V"Mountingit is extremely important that the Antenna bemounted in the clear. Detrimental effects ofsurrounding objects is often underestimatedin the average Antenna installation. Inparticular, power lines and other metalobjects of considerable length or mass willdeteriorate the performance of any installing the Antenna , keep the twohalves balanced with respect to ground andsurrounding objects. Do not attempt toremove all the sag or tremendous strain willdevelop which could cause mechanicalfailure. A few feet of sag in the Antenna wirewill not harm the performance of the 2 BDQ-Seither mechanically or ChartsFigure 8 shows typical SWR curves for thisantenna mounted approximately 50 feet optimum heights for this Antenna on 40meters would be between 20 and 30 feet orgreater than 70 feet.

10 The optimum heights forthis Antenna on 80 meters would be between30 and 70 feet. Heights other than these willproduce SWR in excess of Model 2 BDQ-S may be mounted in the in-verted "V" configuration as shown by thedrawings in this MANUAL . Care must be takento insure that the ends of the Antenna are atleast 16 feet above the ground. Keep theantenna balanced. Anything you do to oneend must also be done to the other end orserious deterioration in performance willresult. One advantage of the inverted "V" isthat you can more nearly match the antennaimpedance to the transmission line im-pedance.