Field Day antenna length table
last updated 18 August 2023.
While I often try to plan our Field Day antennas in advance, part of the fun is that it isn’t always predictable, and sometimes we need another antenna on short notice. So, along with my supply of wire, coax, and rope, I carry a handy table of wire lengths for each band for the antennas I am most likely to put up. That not only saves time (and the potential for errors when I’m in a hurry), but I can hand the paper to someone else to build an antenna.
This table is adapted from a recent version, before I started this website: I haven’t compared it in detail to the other articles I’ve written since, but the numbers should be close enough for a starting point. I’ll get it updated at some point, and add other bands and antenna types. Feel free to make your own table to suit your own needs.
All dimensions are for 1mm (AWG #18) bare wire. In most cases, they should be close enough for other wire sizes likely to be used for portable antennas. There will always be some variation due to how the antenna is constructed, wire insulation type, height above ground, and other factors, but these should give you a good starting point.
Unlike the other tables of antenna dimensions, I’ve split these into separate tables for metric and Imperial units, because most users will only need one or the other.
metric wire length tables (dimensions in meters)
DIPOLE OR INVERTED VEE (length of each side – cut two wires this length)
(or use the Dipole Length Table)
frequency MHz | wire length ( one side ) |
---|---|
1.925 | 37.2 m |
3.55 | 20 m |
3.9 | 18.3 m |
7.15 | 10.14 m |
14.2 | 5.2 m |
21.2 | 3.5 m |
28.5 | 2.6 m |
50.3 | 1.46 m |
53 | 1.40 m |
50 OHM VERTICAL RECTANGLE fed at bottom (cut one wire, tie ropes to corners.)
frequency MHz | wire length | short side | long side |
---|---|---|---|
14.2 | 22.1 m | 3.65 m | 7.4 m |
21.2 | 14.8 m | 2.45 m | 4.95 m |
28.5 | 11.13 m | 1.83 m | 3.73 m |
50.3 | 6.28 m | 1.07 m | 2.07 m |
200 OHM DELTA LOOP (cut one wire, tie ropes to corners.)
frequency MHz | wire length | sides | top / bottom | zip cord matching stub |
---|---|---|---|---|
7.15 | 43.6 m | 12.6 m | 18.3 m | 7.2 m |
14.2 | 21.9 m | 6.1 m | 9.7 m | 3.7 |
21.2 | 14.4 m | 3.9 m | 6.7 m | 2.5 m |
28.5 | 11 m | 2.95 m | 5.0 m | 1.8 m |
50.3 | 6.3 m | 1.77 m | 2.75 m | 1.07 m |
TWO ELEMENT DELTA LOOP BEAM (cut one wire for driven element and one wire for reflector)
frequency MHz | driven element wire length | reflector wire length | spacing |
---|---|---|---|
7.15 | 42.7 m | 46 m | 6 m |
14.2 | 21.35 m | 22.4 m | 3 m |
21.2 | 14.3 m | 15.25 m | 2 m |
28.5 | 10.45 m | 11.58 m | 1.67 m |
50.3 | 6.02 m | 6.48 m | 1 m |
TWO ELEMENT INVERTED VEE YAGI (cut one wire for driven element and one wire for reflector)
frequency MHz | driven element wire length | reflector wire length | spacing |
---|---|---|---|
7.15 | 20.3 m | 21.04 m | 6 m |
14.2 | 10.3 m | 10.6 m | 3 m |
21.2 | 6.86 m | 7.1 m | 2.45 m |
28.5 | 5.08 m | 5.41 m | 1.9 m |
Imperial wire length tables (dimensions in feet and inches)
DIPOLE OR INVERTED VEE (length of each side – cut two wires this length)
frequency MHz | wire length ( one side ) |
---|---|
1.925 | 122 ft |
3.55 | 65 ft 6 in |
3.9 | 60 ft |
7.15 | 33 ft 3 in |
14.2 | 17 ft |
21.2 | 11 ft 6 in |
28.5 | 8 ft 6 in |
50.3 | 57.5 in |
53 | 55 in |
50 OHM VERTICAL RECTANGLE fed at bottom (cut one wire, tie ropes to corners.)
frequency MHz | wire length | short side | long side |
---|---|---|---|
14.2 | 72 ft 6 in | 12 ft | 24 ft 3 in |
21.2 | 48 ft 6 in | 8 ft | 16 ft 3 in |
28.5 | 36 ft 6 in | 6 ft | 12 ft 3 in |
50.3 | 20 ft 7 in | 3 ft 6 in | 6 ft 9 1/2 in |
200 OHM DELTA LOOP (cut one wire, tie ropes to corners.)
frequency MHz | wire length | sides | top / bottom | zip cord matching stub |
---|---|---|---|---|
7.15 | 143 ft | 41 ft 4 in | 60 ft | 23 ft 6 in |
14.2 | 72 ft | 19 ft 8 in | 32 ft | 12 ft |
21.2 | 47 ft 3 in | 12 ft 7 in | 22 ft | 8 ft 3 in |
28.5 | 36 ft | 9 ft 8 in | 16 ft 6 in | 6 ft |
50.3 | 20 ft 8 in | 5 ft 10 in | 9 ft | 3 ft 6 in |
TWO ELEMENT DELTA LOOP BEAM (cut one wire for driven element and one wire for reflector)
frequency MHz | driven element wire length | reflector wire length | spacing |
---|---|---|---|
7.15 | 140 ft | 151 ft | 20 ft |
14.2 | 70 ft | 73 ft 6 in | 10 ft |
21.2 | 47 ft | 50 ft | 6 ft 8 in |
28.5 | 34 ft 4 in | 38 ft | 5 ft 6 in |
50.3 | 19 ft 9 in | 21 ft 3 in | 3 ft |
TWO ELEMENT INVERTED VEE YAGI (cut one wire for driven element and one wire for reflector)
frequency MHz | driven element wire length | reflector wire length | spacing |
---|---|---|---|
7.15 | 66 ft 8 in | 69 ft | 20 ft |
14.2 | 33 ft 9 in | 34 ft 8 in | 10 ft |
21.2 | 22 ft 6 in | 23 ft 3 in | 8 ft |
28.5 | 16 ft 8 in | 17 ft 9 in | 6 ft |