Look at the table bellow. You will be impressed how good characteristics are achieved from this type of antenna!

Everything said for the 144 MHz Twinboom yagis (http://www.qslnet.de/member1/yu7xl/my_tween_boom_yagi_antennas_for.htm) applies for this band antennas, too. Moreover, now good temperature performance emerges in full splendour.

Clicking on the hyperlink in the name of the antenna model, a new page will open offering all details for buiding. Of course, placing the upper and lower booms, you cannot get exact distance between them, Do not worry, a small error will be OK. Actually, this should be the distance between the upper and lower elements.

All elements should be insulated from the booms. All antennas have 200 Ohms impedance at the feeding points and should be fed with 1/2 WL balun made of coax cable 50 Ohms.

Among all performance data, you will see a comparison table where the VE7BQH table is used with the model`s data inserted where it belongs according to its boom length.

The values for gain and G/T ratio are given with inclusion of KF2YN convergence correction. Therefore, the data in green fields in the tables are correct and valid for the material used (for aluminum).

Enjoy! de Boban, YU7XL

TYPE OF
antenna
L
(mm)
L
(λ) 
Single antenna Four antennas in H-stack
GAIN
(dBd)
GAIN
(dBi)
Ta
(K)
Tlos
(K)
G/T
(dB)
F/R
(dB)
1st H
lobe
(dB)
1st V
 lobe (dB)
H lobe
()
V lobe
()
Z
(Ώ)
VSWR at
145 MHz
Bandwidth
for SWR 1.5
(MHz)
E
(m)
H
(m)
Ga
(dBi)
Tlos
(K)
Ta
(K)
G/T
(dB)
Material thickness 5 mm                         Lower Upper            
X71405XL6Q 945 1.36 13.93 11.78 35.4 3.3 -1.56 26.22 23.09 17.76 42.0 36.2 200.6 1.08:1 403.300 442.100 1.28 1.18 20.02 3.3 37.0 4.34
X71605XL4Q 1185 1.73 14.61 12.46 31.9 3.4 -0.43 26.15 27.74 15.86 40.0 32.8 201.2 1.08:1 414.500 441.600 1.28 1.32 20.72 3.4 31.3 5.76
X71805XL5Q 1465 2.10 15.34 13.19 31.4 3.6 0.38 31.11 23.66 16.28 37.2 30.2 199.2 1.02:1 413.000 440.400 1.28 1.38 21.40 3.6 29.7 6.67
X72005XL9Q 1725 2.49 15.88 13.73 29.8 3.6 1.15 35.46 22.24 18.25 34.4 28.4 197.7 1.02:1 417.000 442.000 1.36 1.82 21.97 3.6 28.3 7.46
X72205XL5Q 2005 2.88 16.37 14.22 29.8 3.6 1.64 45.00 22.73 17.91 32.6 26.8 200.8 1.04:1 414.000 442.200 1.40 1.82 22.46 3.6 28.3 7.95
X72405XL4Q 2285 3.29 16.84 14.69 29.9 4.2 2.08 39.35 28.65 19.25 30.8 25.2 197.6 1.07:1 419.000 440.300 1.42 1.86 22.91 4.2 28.2 8.41
X72605XL1Q 2545 3.66 17.10 14.95 29.2 4.2 2.44 34.13 28.34 19.35 29.8 24.8 197.1 1.08:1 417.400 440.200 1.52 1.86 23.16 4.2 28.4 8.62
X72805XL2Q 2815 4.06 17.49 15.34 29.6 4.2 2.78 34.21 26.10 17.72 28.4 23.4 198.2 1.08:1 416.000 441.000 1.74 1.90 23.59 4.2 27.5 9.19
X73005XL3Q 3125 4.50 17.76 15.61 28.1 3.9 3.27 30.19 26.67 20.57 27.9 23.5 200.6 1.08:1 412.000 440.200 1.88 1.88 23.83 3.9 27.2 9.49
X73205XL4Q 3428 4.94 17.92 15.77 27.6 3.9 3.51 30.10 19.98 20.79 27.6 23.5 199.3 1.05:1 418.000 439.800 1.90 1.92 23.99 3.9 27.3 9.64
X73405XL5Q 3725 5.37 18.21 16.06 27.4 3.9 3.84 35.83 21.31 20.65 26.8 22.6 197.2 1.05:1 415.000 439.800 1.94 1.92 24.27 3.9 26.6 10.02
X73605XL4Q 4025 5.80 18.41 16.26 27.4 4.2 4.03 38.22 21.39 20.24 26.2 22.0 198.4 1.07:1 418.000 439.600 1.96 1.96 24.47 4.2 26.6 10.21
X73805XL8Q 4335 6.25 18.86 16.71 27.2 3.9 4.52 39.29 19.57 19.47 24.8 20.8 199.3 1.02:1 413.000 440.000 2.02 2.08 24.93 2.9 27.2 10.59
X74005XL5Q 4635 6.68 19.06 16.91 27.3 4.2 4.69 39.12 19.65 19.04 24.2 20.4 200.2 1.02:1 411.500 440.200 2.08 2.08 25.11 4.2 27.4 10.73
X74205XL4Q 4935 7.11 19.25 17.10 27.2 4.2 4.90 45.79 19.89 18.92 23.8 20.0 198.8 1.03:1 412.000 440.000 2.08 2.32 25.35 4.2 27.4 10.97
X74405XL5Q 5235 7.54 19.42 17.27 27.1 4.2 5.09 46.30 19.87 18.93 23.2 19.7 199.9 1.04:1 412.000 439.800 2.08 2.36 25.53 4.2 27.2 11.17
X74605XL6Q 5535 7.98 19.59 17.44 27.0 4.2 5.27 39.00 20.08 18.58 22.6 19.4 201.1 1.05:1 411.400 439.700 2.12 2.48 25.69 4.2 27.1 11.35
X74805XL5Q 5835 8.41 19.75 17.60 27.0 4.2 5.43 36.54 20.52 18.56 22.2 19.2 199.4 1.04:1 412.500 440.100 2.16 2.56 25.84 4.2 27.1 11.50
X75005XL4Q 6135 8.84 19.91 17.76 26.9 4.2 5.60 35.61 20.52 18.60 21.8 18.8 199.9 1.03:1 413.000 440.000 2.26 2.60 26.01 4.2 27.1 11.67
Material thickness 6 mm                                        
X71406XL1Q 945 1.36 13.95 11.80 33.8 3.0 -1.34 27.25 25.24 16.59 42.2 35.6 198.9 1.07:1 405.700 441.000 1.28 1.18 20.03 3.0 34.3 4.67
X71606XL3Q 1185 1.73 14.67 12.52 31.8 3.1 -0.36 28.65 27.26 15.93 39.6 32.4 201.6 1.02:1 414.500 441.800 1.28 1.32 20.78 3.1 30.7 5.91
X71806XL3Q 1465 2.10 15.36 13.21 30.3 3.0 0.54 25.25 24.04 18.51 36.6 30.1 198.7 1.08:1 417.500 439.800 1.30 1.38 21.40 3.0 29.6 6.68
X72006XL6Q 1725 2.49 15.83 13.69 28.2 3.3 1.33 38.09 22.22 20.11 34.8 28.6 197.2 1.06:1 417.000 440.200 1.36 1.82 21.91 3.3 27.2 7.57
X72206XL9Q 2005 2.88 16.39 14.24 29.4 3.3 1.71 38.37 21.85 19.01 32.6 26.2 198.3 1.05:1 417.000 440.300 1.40 1.82 22.47 3.3 27.8 8.03
X72406XL3Q 2285 3.29 16.79 14.64 28.6 3.3 2.23 31.82 30.03 20.17 31.2 25.6 197.8 1.07:1 413.000 443.000 1.42 1.86 22.86 3.3 27.8 8.42
X72606XL2Q 2545 3.66 17.12 14.97 28.5 3.3 2.57 41.51 28.67 19.23 30.0 25.0 199.6 1.05:1 415.000 442.500 1.52 1.88 23.19 3.3 27.5 8.79
X72806XL4Q 2815 4.06 17.48 15.33 28.2 3.6 2.99 32.64 28.41 19.37 29.0 24.0 200.2 1.02:1 415.000 442.100 1.74 1.86 23.56 3.6 27.2 9.22
X73006XL3Q 3125 4.50 17.74 15.59 27.7 3.0 3.31 31.92 19.69 19.58 28.0 23.9 200.5 1.08:1 413.000 439.500 1.88 1.88 23.83 3.0 26.7 9.56
X73206XL3Q 3428 4.94 18.00 15.85 27.7 3.0 3.57 31.28 19.58 20.08 27.0 23.0 201.3 1.04:1 415.000 440.500 1.90 1.88 24.10 3.0 26.7 9.83
X73406XL5Q 3725 5.37 18.33 16.18 27.3 3.6 3.97 35.18 19.88 19.79 26.3 22.1 200.4 1.05:1 413.000 439.300 1.94 1.92 24.39 3.6 26.3 10.20
X73606XL8Q 4025 5.80 18.59 16.44 27.2 3.6 4.25 38.99 20.24 19.02 25.5 21.5 198.0 1.05:1 414.000 439.600 1.96 1.94 24.63 3.6 26.2 10.45
X73806XL5Q 4335 6.25 18.92 16.77 27.0 3.6 4.61 30.46 18.24 19.36 24.6 20.6 197.7 1.04:1 421.000 439.800 1.98 2.00 24.96 3.6 26.5 10.73
X74006XL5Q 4635 6.68 19.13 16.98 27.1 3.6 4.80 40.02 18.73 20.35 24.0 20.2 198.8 1.08:1 416.000 439.500 2.06 2.08 25.17 3.6 27.1 10.84
X74206XL2Q 4935 7.11 19.32 17.17 27.2 3.6 4.98 48.51 18.68 19.37 23.4 19.8 198.6 1.06:1 416.000 439.800 2.08 2.06 25.33 3.6 26.9 11.04
X74406XL2Q 5235 7.54 19.52 17.37 26.5 3.3 5.29 31.33 19.22 20.01 22.8 19.5 198.8 1.07:1 419.000 439.000 2.06 2.36 25.60 3.3 26.6 11.35
X74606XL5Q 5535 7.98 19.69 17.54 26.8 3.6 5.41 30.18 19.70 19.91 22.2 19.2 200.2 1.06:1 419.000 439.000 2.10 2.60 25.79 3.6 26.7 11.53
X74806XL7Q 5835 8.41 19.88 17.73 26.8 3.6 5.60 31.72 19.71 19.43 21.6 18.9 201.6 1.02:1 419.000 439.000 2.12 2.66 25.97 3.6 26.8 11.69
X75006XL4Q 6135 8.84 20.09 17.94 26.7 3.6 5.83 36.44 18.60 19.04 21.0 18.5 198.5 1.02:1 419.000 439.100 2.06 2.58 26.15 3.6 26.6 11.90
Material thickness 8 mm                                        
X71608XL3Q 1185 1.73 14.71 12.56 31.3 2.4 -0.24 32.24 26.99 16.52 39.5 31.4 198.9 1.07:1 412.400 439.400 1.26 1.32 20.79 2.4 30.1 6.01
X71808XL3Q 1465 2.10 15.44 13.29 30.4 2.1 0.62 25.04 25.26 18.94 36.4 29.8 198.5 1.05:1 423.000 442.000 1.28 1.38 21.48 2.1 30.1 6.70
X72008XL5Q 1725 2.49 15.95 13.89 29.3 2.7 1.27 34.78 31.06 19.30 34.4 28.2 199.5 1.03:1 417.000 444.000 1.36 1.82 22.05 2.7 27.6 7.63
X72208XL2Q 2005 2.88 16.47 14.32 29.7 2.7 1.73 41.62 29.25 17.77 32.2 26.4 198.6 1.06:1 412.000 439.700 1.34 1.82 22.55 2.7 27.4 8.16
X72408XL1Q 2285 3.29 16.90 14.75 29.3 2.7 2.23 34.65 29.05 17.91 30.6 24.8 198.3 1.05:1 410.000 441.400 1.42 1.84 22.97 2.7 27.4 8.59
X72608XL4Q 2545 3.66 17.23 15.08 29.2 2.4 2.58 29.71 27.93 18.41 29.6 24.2 200.0 1.05:1 409.500 441.300 1.72 1.84 23.33 2.4 27.0 9.02
X72808XL3Q 2825 4.07 17.55 15.40 28.5 2.4 3.01 33.14 25.62 17.67 28.4 23.4 201.3 1.03:1 411.000 441.500 1.74 1.86 23.64 2.4 26.2 9.46
X73008XL1Q 3125 4.50 17.89 15.74 28.6 2.7 3.32 32.08 24.60 16.98 27.2 22.2 199.8 1.01:1 413.000 442.000 1.88 1.92 23.98 2.7 26.5 9.76
X73208XL1Q 3425 4.94 18.21 16.06 27.9 2.7 3.75 31.28 25.79 17.55 26.6 21.5 200.2 1.02:1 413.000 441.800 1.90 1.90 24.26 2.7 26.1 10.10
X73408XL1Q 3725 5.37 18.49 16.34 27.6 2.7 4.08 36.47 26.85 17.40 25.8 21.0 198.2 1.01:1 413.000 441.400 1.94 1.92 24.52 2.7 25.9 10.40
X73608XL2Q 4025 5.80 18.73 16.58 27.3 2.7 4.36 39.37 27.48 18.02 25.0 20.6 199.4 1.05:1 413.000 441.200 1.96 1.94 24.74 2.7 26.1 10.58
X73808XL1Q 4335 6.25 18.94 16.79 27.2 2.7 4.59 38.14 26.87 16.49 24.2 20.0 199.9 1.04:1 415.000 440.500 1.98 2.00 24.97 2.7 26.1 10.81
X74008XL1Q 4335 6.25 19.17 17.02 27.0 2.7 4.87 45.55 27.80 16.00 23.4 19.6 198.2 1.03:1 415.000 440.400 2.04 2.08 25.21 2.7 26.4 11.00
X74208XL1Q 4935 7.11 19.39 17.24 26.9 2.7 5.10 47.36 23.88 15.85 22.6 19.2 197.3 1.05:1 415.000 440.500 2.06 2.04 25.39 2.7 26.0 11.25
X74408XL1Q 5235 7.54 19.59 17.44 26.6 2,7 5.35 40.10 20.12 15.99 22.0 19.0 198.5 1.07:1 415.000 441.200 2.08 2.06 25.58 2.7 25.9 11.46
X74608XL1Q 5535 7.98 19.78 17.63 26.7 3.0 5.51 31.83 19.83 16.00 21.4 18.6 197.7 1.08:1 411.000 441.400 2.10 2.60 25.87 3.0 27.3 11.52
X74808XL1Q 5835 8.41 19.95 17.80 26.6 3.0 5.70 33.38 19.30 15.75 21.0 18.4 199.5 1.07:1 411.000 441.700 2.12 2.62 26.04 3.0 27.0 11.73
X50808XL4Q 6135 8.84 20.13 17.98 26.4 3.0 5.91 34.65 19.03 15.95 20.4 18.2 200.1 1.06:1 412.000 441.800 2.14 2.64 26.21 3.0 26.7 11.94