Hy-Gain 2BDQ-S User Manual

ORDER NO. 380S
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Model 2BDQ-S
Trap Dipole Antenna
INSTRUCTION MANUAL
General Description
The Hy-Gain Model 2BDQ-S is a 1/2 wavelength, dipole antenna for 40 and 80 meters. Band switching is accomplished automatically through the use of two matched Hy-Gain 40-m eter Hy-Q t raps. The maximum overall length is 100' 10 1/2". If the antenna is mounted in an inverted "V" configuration, the overall length will be shorte ned.
The balun will improve the performance and efficiency of the 2BDQ-S. The Hv-Gain Model BN-86 is a broadband balun designed specifically for dipole-type antennas. The balun balances the input impedance to the antenna and prevents transmission line radiation.
Theory of Operation
Matched Hy-Gain Hy-Q traps give true 1/2­wave resonance. They are tuned at the factory and no adjustments are necessary. They operate as a high impedance circuit on 40 meters and add to the overall length of the antenna as center loading for the 80/75 meter resonance.
The Hy-Q traps will withstand h ard wear and severe weather conditions. All hardware is passivated stainless steel. The center of the dipole is supported with a yoke-type center insulator to which the transmission line attaches. The ends of th e dipole are suppo rted by two end insulators constructed of high impact ABS plastic. The antenna wire is Alumoweld© #12, which resists rust and has a breaking strength of 1200 pounds.
SWR and Feedline
The 2BDQ-S antenna is designed for use with single 50 ohm coaxial feedline. The SWR at resonance is 1.5:1 or less on both bands.
Alumoweld® is a registered trademark of Copperweld Bimetallic Grou
Assembly Procedure
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Referring to Figure 1, place one half of the center insulator (Item No.7) on a flat surface with the inside facin
.
Assemble the hardware on the eyebolts an
lace in the insulator.
Figure 1 Ass embl y of Antenn a Wi re to Cent er
Insula tor
Strip the coax and s eparate the center condu c­tor from the braid. Solder the braid to one solder lug (Item No. 22) and the center conductor to the other solder lug. For a smaller coax , a reducing sleeve is provided.
Apply silicone gr ease or V aselin e®, etc . (not supplied) to the matin g halves.
Place the halves together and secure them using the #6-32 x 3/8" bolts and nuts (Item Nos. 15 & 16).
Hold the eyebolt to keep it from turning and tighten the 1/4" nuts on the outside, first one
NOTE: Both sides of the antenna are exactly the same. Each of the following steps must be done first for one side then repeated for the other side.
Cut the 40-mete r wire (LI) to eithe r Phone or Continuous Wave (CW) dimensions as shown in Figures 2 and 3. Add an extra thr ee inches on each end for attaching to the center insulator and 40-meter trap. Example: Ll length for CW operation is 19' 8 1/4". Add six inches, three inches each end, which makes a total length of 20' 2 1/4". Each insulator or trap requires three inches for proper attachm ent. NOTE: When you have selected your mode of transmission (Phone o r CW), you must us e the same mode for all dimensions .
Attach one end of the wire (just cut) to the center insulator (Item No.7) using the wire locks as shown in Figure 1. Do not forget to connect th e pigtail to the wire lock.
Clip off all excess wire extendin g past the wire lock.
Select the 40-meter trap and the trap connector clamps. Assemble the clamps on both ends of the trap using the #10-24 x 1 1/2" bolts, lockwashers, and nuts (Item Nos. 9, 11, and 10), as shown in Figure 4.
Carefully remeasure the antenna wire con­nected to the center insulator and bend the wire for attachment to the 40-meter trap as shown in Figures 2 and 3.
Connect the wire to the trap using the wire locks (Item No. 5) and shown in Figure 4. Clip off all excess wire extending past the wire lock.
Figure 2 Antenna Wire
is a registered trademark of Chesebrough -Ponds,
Measurements
NOTE: The end of the trap which has a small bolt must be
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pointed in the direction of the center insulator as shown in Figures 3 and 4. This is very important for proper operation of the antenna.
Use only one bolt on the side of the clamp opposite the drain holes. An off-center wire attachment is used to keep the drain holes downward. Remove the twists and kinks from the wire prior to the installation to insure that the traps do not rotate in the final mounting position.
Ite Ite
o. Description 4Clam 5 Wire Lock 14 Lockwasher, internal, #8 9 Bolt, hex head, #10-24 x 1 1/2" 17 Bolt, hex head, 1/4"-20 x
10 11 Lockwasher, internal, #10 20 Lockwasher, internal 1/4" 12 Bolt, ro und he a d, #8 -32 x 112"
, Trap Connector 13
ut, hex, #10-24 19
o. Description
ut, hex, #8-32
ut, hex, 1/4" -20
Figure 4 Assembly of the Antenna Wire
to the Tra
Cut the 80-meter antenna wire (L2) to the length shown for your mode of transmission (Phone or CW). Do not forget to allow an extra three i nches on each end for attachm ent to the 40-meter tr ap and end insul ator.
Bend one end of the wire and attach to the 40meter trap as shown in Figures 2 and 4. Do not forget to clip off the excess wire
Carefully remeas ure wire and bend for att ach­ment to the end insulator.
Attach the wire to the end insulator as shown in Figure 5. Clip off all excess wire extending past the wire lo ck.
Item
No. Description
1 Wire, Antenna, Alumoweld #12 by 100 ft. 2 Insulat o r, End 5 Wire Lock 12 Bolt, round head, #8-32 x 1/2"
Assembly of the Antenna Wire to th e End Insul ator
Mounting
The antenna is now ready to be mounted in either the horizontal or inverted "V" configuration. Refer to Figures 6 and 7 for proper dimensions. When suspending the end insulators, non-metallic line is preferred. If you do use «ire, it must be broken up every six feet with strain insulators to prevent harmful effects to your radiatio n pattern.
Figure 5
Suspend the antenna by attaching the end in­sulators to a stable structure. The center in­sulator may be supported by the antenna itself or suspended from a support. When suspending the center insulator from a support, be sure to keep the insulator from contacting any of the supporting structure. For proper operation of this antenna, the center insulator should be about 46 feet above the ground. The higher the a ntenna, the better the operation.
Figure 6 Horizontal
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Mountin
Figure 7 Inverted "V "
Mounting
it is extremely important that the antenna be mounted in the clear. Detrimental effects of surrounding objects is often underestimated in the average antenna installation. In particular, power lines and other metal objects of considerable length or mass will deteriorate the performance of any antenna. When installing the antenna, keep the two halves balanced with respect to ground and surrounding objects. Do not attempt to remove all the sag or tremendous strain will develop which could cause mechanical failure. A few feet of sag in the antenna wire will not harm the performance of the 2BDQ-S either me chanic ally or electrically.
A Model 2BDQ-S may be mounted in the in­verted "V" configuration as shown by the drawings in this manual. Care must be taken to insure that the ends of the antenna are at least 16 feet above the ground. Keep the antenna balanced. Anything you do to one end must also be done to the other end or serious deterioration in performance will result. One advantage of the inverted "V" is that you can more nearly match the antenna impedance to the transmission line im­pedance. A directional pattern, in the direction of the slant, will result if angle "A" (as shown in Fi gure 7) ex ceeds 35 de grees.
VSWR Charts
Figure 8 shows typical SWR curves for this antenna mounted appr oximately 50 feet above
round.
The optimum heights for this antenna on 40 meters would be between 20 and 30 feet or greater than 70 feet. The optimum heights for this antenna on 80 meters would be between 30 and 70 feet. Heights other than these will
roduce SWR in exc ess of 1.5: 1.
Figure S Typical SWR Curves for
this Antenna Installed 50 feet
Above Ground
Hints on Handling Alumoweld© Wire To meet the numerous re quests for a n on-cor-
rosive, super strength wire, Hy-Gain is now using Alumoweld© wire in many wire-type antennas and mounting kits.
Alumoweld© wire meets Military Specifications for virtually all environmental conditions. The wire is designed for arcs of high humidity and salt exposures as well as other less durable forms of wire but the lasting properties are far superior. Conducting properties closely approach that of pure aluminum making it ideal electrically for RF use.
There may be some difficulty encountered in working with the wire due to its tendency to kink. Kinks may be removed by a pole or similar stationary curved object and working the wire b ack an d forth a s shown in Figure 9.
Figure 9 Removing Kinks from
Alumoweld Wire
PARTS LIST
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No. Part No. Description Qt
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1 691067 Wire, Antenna, Alumowel #12 by 100 ft. .........................1
2 861021 Insulator, End......... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...2
3 877234 Trap Assembly, 40-Meter..........................................................2
877233-1 Parts Pack 380 S, Stai nles s S teel .. .... .... .... .... .... .... .... .... .... .... .... .. 1
4 167236 Clam
, Trap Connector... ...... ...... ...... ...... ...... ..... ....... ...... ...... 8
5 1672 38 Wire Lock... ...... ...... ..... ....... ...... ...... ...... ...... ..... ...... .... ...... ...... 16
6 171586 Sleeve
Mounting Hole...... .... .... .... .... .... .... .... .... .... ... 1
7 465460 Insulator, C ent er. .... .... .... ... ..... .... .... .... .... .... .... ... ..... .... .... .... .... 2
8 465570 Plug, Center Insulator Adaptor............................................ 1
9 500159 Bolt, hex head, #10-24 x 11/2 "... ...... ...... ...... .... ....... ...... .......8
10 55 4071 Nut, hex, # 10-24 ………….. ...... ...... ...... ...... ...... ...... ...... ...... ..... 8
11 565697 Lock-washer, internal, #10 .................................................,.. 8
12 50 0185 Bolt, rou nd h ead , #8 -32 x 1/ 2".. .... .... .... .... .... .... .... ..., .... .„. .... 8
13 550063 Nut, hex, #8-32...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... .....8
14 560035 Lockwasher, internal, #8.......... ...... ...... ...... ...... ...... ...... ....,..„ 8
15 501118 Bolt, round head, #6-32 x 3 /8".. .... .... .... .... .... .... .... .... .... ...,..14
16 55 5888 Nut, hex, #6 -32.. .... .... ... ..... .... .... .... .... .... .... .... .... .... .... .... .... ...1 4
17 50 5266 Bolt, hex head , 1/4" -20 x 3/4 "...... ...... ...... ...... ....., ...,.. ...... ,.„„. 4
18 540066 Eyebolt, 1/2" eye, 1/4" x 11/2 ". ...... ...... ...... ...... ...... ...... ...... ....2
19 554099 Nut, hex, 1/4"-20..... ..... ....... ...... .... ...... ...... ...... ...... ..... ...... ...... 14
20 56 2961 Lockwasher, inter nal, 1 /4" .... ...... ...... ...... ...... ...... ...... .,.,.. ..„„ . 8
21 566344 Flatwasher, 1/4".......................................................................4
22 67 7555 Lug, Solder……… ……….. ....... ...... ...... ...... ...... ........ ...... ...... ... 2
23 878466 Pigtail Assembly ..................................................................... 2
Converting American
to Metric
Use this scale to identify lengths of bolts, diameters of tubes, etc.. The American inch (1") and foot (1') can be converted to centimeters in this way.
1 inch (1 ") = 2. 54 c m 1 foot (1') = 30.48 cm
Example
42" x 2.54 = 106.7 cm
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