Here are some lengths and spacings for various direct connect beams. The layouts are straight forward and are illustrated below. Your SWR should be less than 1.3:1 with these designs.
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The driven element is cut into two halves and insulated from the boom with nonmetalic material. Then the two wires of the coax are connected, one to each section of the driven element. You may drill small holes and use sheet metal screws to accomplish this.
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The reflector, director 1, and director 2 can be attached directly to the boom by a variety of methods. There are some helpful hints for antenna construction on our Antenna Construction Tips page.
70 Centimeter 2 element beam center frequency 440 MHz 1/8" diameter tubing
Element Length Element spacing from Reflector
Reflector 12-3/8" *****
Driven 12-1/8" 6-1/2
Freespace Over ground 30 feet
Gain 4.17 dbd 8.08 dbd @ 5 degrees 9.48 dbd @ 14 degrees
F / B 4.01 db 4.0 db
70 Centimeter 4 element beam center frequency 440 MHz 1/8" diameter tubing
Element Length Element spacing from Reflector
Reflector 13" *****
Driven 12" 8-1/16"
Director 1 11-7/8" 16-3/4"
Director 2 11-3/4" 23-3/8"
Freespace Over ground 30 feet
Gain 8.19 dbd 12.78 dbd @ 5 degrees
13.05 dbd @ 14 degrees
F / B 11.15 db 11.2 db
2 Meter 4 element quad center frequency 145.000 MHz #12 copper wire
Element Length Element spacing from Reflector
Reflector 21-1/4" *****
Driven 21" 23-1/8"
Director 1 20-1/4" 46-1/4"
Director 2 20-3/16" 74"
Freespace Over ground 30 feet
Gain 8.87 dbd 10.24 dbd @ 5 degrees
13.87 dbd @ 8 degrees
F / B 8.57 db 8.7 db
2 Meter 4 element beam center frequency 146.52 MHz 1/2" diameter tubing
Element Length Element spacing from Reflector
Reflector 38-1/8" *****
Driven 36" 24-1/4"
Director 1 34-1/2" 49"
Director 2 34-3/8" 71-1/2"
Freespace Over ground 30 feet
Gain 8.43 dbd 10.34 dbd @ 5 degrees 13.71 dbd @ 10 degrees
F / B 13.32 db 13.60 db at 5 degrees
2 and 6 Meter 4 element quad center frequency 146.520 / 52.000 MHz #12 copper wire
Element Length Element spacing from Reflector
6 Meter Reflector 60-1/4" *****
6 Meter Driven 57-9/16" 48-3/8"
2 Meter Reflector 21-1/4" 54"
2 Meter Driven 20-1/2" 77-1/4"
2 Meter Director 1 20-1/4" 100-1/4"
6 Meter Director 1 57-1/16" 104-3/4"
2 Meter Director 2 20-3/16" 128"
6 Meter Director 2 49-1/2" 181-15/16"
Freespace Over ground 30 feet
Gain 8.3 / 8.35 dbd 13.97 dbd @ 2 degrees 13.79 dbd @ 8 degrees
F / B 7.86 / 15.84 db 8.12 / 16.59 db
6 Meter 3 element beam center frequency 52.000 MHz 1" diameter tubing
Element Length Element spacing from Reflector
Reflector 109" *****
Driven 101-5/8" 64-15/16"
Director 1 96-3/4" 125-3/16"
Freespace Over ground 30 feet
Gain 6.5 dbd 9.99 dbd @ 5 degrees 12.01 dbd @ 8 degrees
F / B 8.99 db 9.25 db
6 Meter 4 element beam center frequency 52.000 MHz 1/2" diameter tubing
Element Length Element spacing from Reflector
Reflector 109-7/8" *****
Driven 104-1/4" 72"
Director 1 100.5" 138"
Director 2 100" 204"
Freespace Over ground 30 feet
Gain 8.2 dbd 11.78 dbd @ 5 degrees 13.76 dbd @ 8 degrees
F / B 14.44 db 15.28 db
10 Meter beam center frequency 28.450 MHz 1/2" diameter tubing
Element Length Element spacing from Reflector
Reflector 207-1/2" *****
Driven 192" 105"
Director 1 185" 210"
Freespace Over ground 30 feet
Gain 6.33 dbd 5.49 dbd @ 5 degrees 11.49 dbd @ 10 degrees
F / B 10.21 db 10.37 db
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