VHF / UHF Direct Connect Beams
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.
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.
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
70 Centimeter 2 element beam 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
70 Centimeter 4 element beam 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
2 meter 4 element quad #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
2 Meter 4 element beam 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
2 and 6 Meter 4 element quad #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
6 Meter 3 element beam 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
6 Meter 4 element beam 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
10 Meter 3 element beam 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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