Introduction

This page presents a series of 2-Element HF antennas that are easily constructed, "easily matched and easily tuned". By "easily matched and easily tuned" it is meant that, these antennas can be constructed and tuned on the ground. When the antenna is finally placed at height, there will only be a small decrease in F/B ratio. But the decrease is small and not worth trying to tune at height.

Note: The feed impedance for these yagi designs is 18-20 Ω. This means that a matching device will be necessary for the driven element, if you want to use 50/75 Ω coax or 75/300/450 Ω Ladder Line. See the web page on 2 and 3 Element Yagi Matching.

2-Element Parasitic Beam
For 6, 10, or 40 Meters
2-Element Parasitic Beam
For 11, 15, or 20 Meters
Power Gain = 4.8 dB
F/B Ration = 12 dB
Radiation Resistance = 20 Ohms
Power Gain = 5.3 dB
F/B Ration = 12 dB
Radiation Resistance = 18 Ohms
Driven Element Length
471/FMHz (ft) || 143/FMHz (m)
Director Length
435/FMHz (ft) || 133/FMHz (m)
Element Spacing
120/FMHz (ft) || 37/FMHz (m)
Driven Element Length
475/FMHz (ft) || 145/FMHz (m)
Director Length
448/FMHz (ft) || 137/FMHz (m)
Element Spacing
120/FMHz (ft) || 37/FMHz (m)
Bandwidth for 1.75:1 SWR
 325 KHz at 40 Meters
1600 KHz at 10 Meters
2800 KHz at 6 Meters
Bandwidth for 1.75:1 SWR
475 KHz at 20 Meters
700 KHz at 15 Meters
875 KHz at 11 Meters
Diameter of Elements
40 Meters = 2"
10 Meters = 1-1/2"
6 Meters = 1"
Diameter of Elements
20 Meters = 1-1/2"
15 Meters = 1"
11 Meters = 1"

The table on the right is similar to the table in Bill Orr's1 book. I updated the table to include current references and metric dimensions. The antennas are separated into two groups and have slightly different gains. This is because the bands on the left (6, 10, and 40 Meters) have a greater operating bandwidth (>3% at the design frequency). For these bands, the gain is lowered so that the antenna covers a larger bandwidth. Whereas, the bands on the right (11, 15, and 20 Meters) are much narrower (<3% at the design frequency) and can realize a higher gain and still cover the whole band with an SWR <= 1.75:1.

It is important to note that Bill Orr uses a parasitic director in front of the driven element, rather than a a parasitic reflector behind a driven element. This configuration provides higher forward gain and a greater F/B ratio than a configuration using a parasitic reflector.

Some time ago, I set up a group of simulations for 2-Element 10 Meter arrays with parasitic reflectors, parasitic directors, and varying element spacing from 0.02 to 0.30 λ, in 0.01 λ increments. From these simulations, I found that a parasitic director provides for a better F/B Ratio and higher Forward Gain, over a 2-Element array with parasitic reflectors and the same spacing. The best Forward Gain and best F/B Ratio does not happen at the same element spacing, but the 0.12 λ spacing does seem to be a good compromise.

The antennas in the table are detailed below. For the most part, the text associated with each antenna is pretty generic. However, if there is anything specific about an antenna, it will be listed in the description

2-Element 6 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 6 Meter antenna. A General Coverage frequency (51.5 MHz) is selected as this provides the best coverage of the 6 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 6 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (2 inches) across the 6 Meter band. The spacing listed on the diagram is a good mean value.

50
51
52
53
54
Frequency (MHz)
7'
8'
9'
10'
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General Coverage
Operation
(Low End)
Driven Element (A)
Director (D)
Top View
A
D
2' 3" (71.0 cm)
4.8 dB
Element Diameter = 1"
50
51
52
53
54
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 50 MHz, 2-Element Parasitic Array.
For General Coverage (50-53 MHz) A = 9′ 4", D = 8′ 4", S = 2′ 3"
SWR vs Frequency for 2-Element
Beam Resonated at 51.5 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length

471/FMHz
Dir
Length

435/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
4.8 dB 12 dB 20 Ω 9' 1"
278.8 cm
8' 5"
257.5 cm
2' 3"
71.0 cm
2,800 KHz 1"
2-Element 10 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 10 Meter antenna. A General Coverage frequency (28.75 MHz) is selected as this provides the best coverage of the 10 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 10 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (3 inches) across the 10 Meter band. The spacing listed on the diagram is a good mean value.

28.0
28.5
29.0
29.5
30.0
Frequency (MHz)
14'
15'
16'
17'
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General Coverage
Operation
Driven Element (A)
Director (D)
Top View
A
D
4' 2" (127.2 cm)
4.8 dB
Element Diameter = 1-1/2"
28.0
28.5
29.0
29.5
30
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 28 MHz, 2-Element Parasitic Array.
For General Coverage (28-30 MHz) A = 18′ 4", D = 15′ 2", S = 4′ 2"
SWR vs Frequency for 2-Element
Beam Resonated at 28.75 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length

471/FMHz
Dir
Length

435/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
4.8 dB 12 dB 20 Ω 16' 5"
4.993 M
15' 2"
4.612 M
4' 2"
1.272 M
1,600 KHz 1-1/2"
2-Element 11 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 11 Meter antenna. A General Coverage frequency (27.1 MHz) is selected as this provides the best coverage of the 11 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 11 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (1 inch) across the 11 Meter band. The spacing listed on the diagram is a good mean value.

26.9
27.0
27.1
27.2
27.3
Frequency (MHz)
16'
17'
18'
E
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General Coverage
Operation
Driven Element (A)
Director (D)
Top View
A
D
4' 5" (135.0 cm)
5.3 dB
Element Diameter = 1"
26.9
27.0
27.1
27.2
27.3
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 27 MHz, 2-Element Parasitic Array.
For General Coverage (26.9 - 27.3 MHz) A = 17′ 6", D = 16′ 6", S = 4′ 6"
SWR vs Frequency for 2-Element
Beam Resonated at 27.1 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length

475/FMHz
Dir
Length

448/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
5.3 dB 12 dB 18 Ω 17' 6"
5.342 M
16' 6"
5.039 M
4' 5"
1.35 M
875 KHz 1"
2-Element 15 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 15 Meter antenna. A General Coverage frequency (21.2 MHz) is selected as this provides the best coverage of the 15 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 15 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (2 inches) across the 15 Meter band. The spacing listed on the diagram is a good mean value.

21.0
21.1
21.2
21.3
21.4
21.5
Frequency (MHz)
20'
21'
22'
23'
E
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General Coverage
Operation
Driven Element (A)
Director (D)
Top View
A
D
5' 7" (172.5 cm)
5.3 dB
Element Diameter = 1"
21.0
21.1
21.2
21.3
21.4
21.5
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 21 MHz, 2-Element Parasitic Array.
For General Coverage (21.0 - 21.45 MHz) A = 22′ 5", D = 21′ 1", S = 5′ 7"
SWR vs Frequency for 2-Element
Beam Resonated at 21.2 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length

475/FMHz
Dir
Length

448/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
5.3 dB 12 dB 18 Ω 22' 5"
6.829 M
21' 2"
6.441 M
5' 8"
1.725 M
700 KHz 1"
2-Element 20 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 20 Meter antenna. A General Coverage frequency (14.2 MHz) is selected as this provides the best coverage of the 20 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 20 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (3 inches) across the 20 Meter band. The spacing listed on the diagram is a good mean value.

14.0
14.1
14.2
14.3
14.4
Frequency (MHz)
31'
32'
33'
34'
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General Coverage
Operation
Driven Element (A)
Director (D)
Top View
A
D
8' 5" (257.6 cm)
5.3 dB
Element Diameter = 1-1/2"
14.0
14.1
14.2
14.3
14.4
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 14 MHz, 2-Element Parasitic Array.
For General Coverage (14.0 - 14.4 MHz) A = 33′ 5", D = 31′ 5", S = 8′ 6"
SWR vs Frequency for 2-Element
Beam Resonated at 14.2 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length

475/FMHz
Dir
Length

448/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
5.3 dB 12 dB 18 Ω 33' 5"
10.196 M
31' 7"
9.616 M
8' 5"
2.576 M
435 KHz 1-1/2"
2-Element 40 Meter Antenna

The diagram below contains all the information you would need to build a 2-Element 40 Meter antenna. A General Coverage frequency (7.160 MHz) is selected as this provides the best coverage of the 40 Meter band. The SWR chart on the right show the General Coverage antenna's SWR performance, within the 40 Meter band. If you wish to use a center frequency above or below the General Coverage frequency, the Element Length .vs. Frequency chart can be used to determine new element lengths. The chart only lists the length of the driven and director elements. The Element Spacing can be kept the same, as there is very little change (10 inchs) across the 40 Meter band. The spacing listed on the diagram is a good mean value.

7.0
7.1
7.2
7.3
Frequency (MHz)
59'
60'
61'
62'
63'
64'
65'
66'
67'
68'
E
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General Coverage
Operation
Driven Element (A)
Director (D)
Top View
A
D
16' 9" (510.8 cm)
4.8 dB
Element Diameter = 2"
7.0
7.1
7.2
7.3
Frequency (MHz)
1
1.5
2.0
S
W
R
General
Coverage
Operation
Element Lengths for 7 MHz, 2-Element Parasitic Array.
For General Coverage (7.0 - 7.3 MHz) A = 65′ 11", D = 60′ 10", S = 17′ 0"
SWR vs Frequency for 2-Element
Beam Resonated at 7.160 MHz.

The table below can also be used to determine Driven and Director elements for a frequency other than the General Coverage frequency. Just select your center frequency from the drop-down selector listed under the Frequency catagory. The dimensions for the Driven and Director elements, and the Element Spacing, will automatically be updated.

Gain F/B
Ratio
Rad.
Res.
Frequency DE
Length
<
471/FMHz
Dir
Length

435/FMHz
Element
Spacing

120/FMHz
1.75:1 SWR
Bandwidth
Element
Diameter
4.8 dB 12 dB 20 Ω 65' 10"
20.078 M
60' 10"
18.544 M
16' 9"
5.116 M
325 KHz 2"