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The W8IO Antenna Site

VHF-UHF Long Boom, Very High Performance Antenna Designs

(links updated 27 Sep 2016)


From this data and these NEC files, you can compare the performance between the various models without manufacturer hype. You could also build your own long beam if you have the right tools/test equipment and the knowledge of how to make the boom corrections. Back in the 1970's and 1980's, US hams had the advantage in designing and building state of the art, high performance antennas for VHF/UHF. Today, the Europeans seem to have taken the lead. I would like to encourage more experimentation and home building by North American VHF/UHFers!  It's also less expensive.  Check out the price of the popular LFA Yagis from England!

For contest and normal terrestrial operations, I would choose the antenna with the most forward gain for a given boom length. The sidelobes and backlobes are only important if you have noise generators or other stations that you need to eliminate in those directions. For EME use, I would choose the antenna with the highest G/T or the best F/R and lowest sidelobes for a given boom length. VE7BQH's G/T values are given for 4 bay arrays with specific boom spacing.  Please refer to his note for complete details. VK3DIP's YagiCAD will calculate a similar G/T for a single Yagi system. Most of the long boom antennas shown below are what I consider to be Very High Performance Yagis. I have separated out those antennas which I have called Ultra High Performance Yagis.  These UHP Yagis will have F/R greater than 30 dB in both planes and first sidelobes at -20 dB or better from the main lobe. Also, these UHP Yagis will have gain at or above the DL6WU gain curve.


Experimental Long Boom Antennas - CP, LPDA, multiband, etc.
Model Directive Gain (dBi) G/T E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file Az Pattern Elev Pattern
W8IO-216CP 12.3 dBic - 18 18 10.5 - 216CP - - -
W8IO-LP144-22 14.3 - 35 35 22 - LP144-22 LP144-22 LP144-22-az LP144-22-el
W8IO-LP144-35-MAXFB 16.34 - 48 37 32 9.7 LP144-35MAXFB LP144-35MAXFB LP144-35-MFB-az LP144-35-MFB-el
W8IO-LP140-200-2D 12.2 to 11.5 - 23+ - 15 - LP140-200-2D LP140-200-2D LP140-200-az LP140-200-el
W8IO-LP50-108 8.0+ - 30 - 12 - LP50-108-16 LP50-108-16 - -

The experimental designs shown above have not yet been built or tested.

The 216CP features a single-point feed for a 50 ohm input RHCP beam. This beam covers the entire 144-148 MHz band under 1.5 VSWR and produces 12.3 to 13.1 dBic gain (RHCP) with no phasing lines. F/B peaks at 20 dB near 145.5 MHz.

The LP144-22 is a narrow band LPDA (Loggi) that covers 144-148 MHz under 1.5 VSWR.  It produces 14.1 - 14.3 dBi across the band with better than 30 dB F/R also from 144-148 MHz. Peak F/R is 35 dB near 144.2 MHz. Sidelobes are also less than 30 dB.

The LP144-35-MAXFB is also a narrow band LPDA (Loggi) that covers 144-148 under 1.5 VSWR.  It produces 16.34 dBi at 144.1 and gradually less gain at higher frequencies. The main feature of this design is the 47.7 dB F/R
and 73 dB F/B at 144.1 MHz. F/R is better than 40 dB from 144-144.6 MHz. Sidelobes are also less than -28 dB.

The LP140-200-2D is a 23 element LPDA-Yagi for 140 to 200 MHz. It produces 12.2 dBi gain and 37 dB F/R at 144.1. The gain gradually declines to 11.5 dBi at 210 MHz with 23 dB F/B. This design uses 2 director elements to enhance the gain at 200 MHz.
 


Send me your experimental designs or data so that I can share them here!

VHF/UHF Long Boom Antenna Project Pages


VHF-UHF Misc Antenna Links


50 MHz long boom Yagi NEC files (23-36 foot booms)

Model Directive Gain (dBi) E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file Az Pattern Elev Pattern Best US  Price
(April 28, 2015)
Hy-Gain 66DX 11.3 19.3 14.8 24.5 7.46 HG-66DX-CW HG-66DX-CW 66DX-az 66DX-el $239.95
YU7EF EF0606 11.89 25.38 20.9 23 7.0 EF0606 EF0606 EF0606-az EF0606-el -
KF6A-50-7-1.46WL12.7926.8720.0628.68.72KF6A-1.46WLKF6A-1.46WLKF6A-1.46WL-azKF6A-1.46WL-el-
KF6A-50-7L 12.98 26.57 24.28 29.2 8.9 KF6A-7L KF6A-7L KF6A-7el-az KF6A-7el-el -
KF6A-50-8L13.4528.0221.4636.111KF6A-50-8LKF6A-50-8LKF6A-50-8L-azKF6A-50-8L-el-

The antennas shown in red are experimental and have not yet been built or tested. F/R includes all backlobes.


144 MHz long boom Yagi NEC files (22-37 foot booms)

Model Directive Gain (dBi) VE7BQH
G/T (dB)
E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file Az Pattern Elev Pattern Best US  Price
(Apr 28)
UR5EAZ-RS-2-1115.06-29.5622.3719.425.92UR5EAZ-RS-2-11UR5EAZ-RS-2-11UR5EAZ-RS-2-11-azUR5EAZ-RS-2-11-el-
UR5EAZ-RS-2-12 15.52 -2.13 30.11 24.03 22.3 6.796 UR5EAZ-2-12 UR5EAZ-2-12 UR5EAZ-az UR5EAZ-el -
UR5EAZ-RS-2-12
W8IO optimized
15.67 - 33.42 23.5 22.44 6.84 UR5EAZ-2-12-W8IO-opt - - - -
K1FO FO15-144 15.97 -1.8 20 19.7 24.8 7.566 K1FO-FO15-144 FO15-144 FO15-az FO15-el $279.95
W8IO-144-13U 16.12 - 34.43 24.55 25.4 7.75 W8IO-144-13U W8IO-144-13U - - -
KF6A 2M12L16.31-1.39#29.5725.2525.857.88KF6A-2M12LKF6A-2M12LKF6A-2M12L-azKF6A-2M12L-el-
G0KSC-13LFA 16.1 -1.31 27 27.4 26 7.937 G0KSC-13LFA 13LFA 13LFA-az 13LFA-el $392.43
+ $96 shipping
DK7ZB-144-12 16.5 -1.49 28 25.6 26.1 7.960 DK7ZB-144-12 144-12 DK7ZB-12-az DK7ZB-12-el -
YU7EF EF0213 16.2 -1.28 23 22.5 26.7 8.15 YU7EF-EF0213 EF0213 EF0213-az EF0213-el -
W8IO-144-13a 16.32 -1.27* 27.25 26.64 26.7 8.14 W8IO-144-13a W8IO-144-13a W8IO-13a-az W8IO-13a-el -
DG7YBN 144-GTV2-14w 16.3 -1.20 33.27 28.1 27.16 8.278 DG7YBN GTV2-14w GTV2-14w GTV2-14w-az GTV2-14w-el -
W8IO-144-14V* 16.27 -1.18* 34.6 30.04 27.16 8.278 W8IO-144-14V W8IO-144-14V 144-14V-az 144-14V-el -
BVO-4WL-144-15 16.4 -1.25 24.7 24 27.2 8.3 BVO-4WL-144-15 4WL-144-15 4WL-144-15-az 4WL-144-15-el -
SM5BSZ 2SA13 16.6 -1.22 19.8 19.6 27.4 8.35 SM5BSZ-2SA13 2SA15 2SA13-az 2SA13-el -
K1FO FO16-144 16.33 -1.43 23.7 23.8 27.4 8.352 K1FO-FO16-144 FO16-144 FO16-144-az FO16-144-el -
WB0DGF Hy-Gain 215DX 16.35 -1.49 20 19.5 27.5 8.379 WB0DGF-215DX 215DX 215DX-az 215DX-el $199.95
W8IO-144-14U 16.43 - 34.09 26.89 28.3 8.62 W8IO-144-14U W8IO-144-14U - - -
G0KSC-14LFA 16.55 -0.84 28.4 26.8 28.9 8.817 G0KSC-14LFA 14LFA 14LFA-az 14LFA-el $426.45
+$120 shipping
W8IO-144-15V 16.58 -0.80** 34.33 31.53 30.0 9.14 W8IO-144-15V W8IO-144-15V 144-15V-az 144-15V-el
I0JXX 16JXX216.65-1.0028.1326.4830.59.316JXX216JXX216JXX2-az16JXX2-el213.11 Eur
($234)
Cushcraft A17B2 16.77 -1.01 24.7 23.4 31 9.45 CC A17B2 17B2 17B2-az 17B2-el $329.95
W8IO-144-15U 16.78 - 35.03 24.43 31.2 9.52 W8IO-144-15U W8IO-144-15U - - -
G0KSC-15LFA-EU 16.83 -0.48** 29.16 26.14 32.3 9.85 144-15LFA 144-15LFA 144-15LFA-az 144-15LFA-el $504.95
+$120 shipping
W8IO-144-16V 16.87 -0.55** 35.8 32.3 32.3 9.86 W8IO-144-16V W8IO-144-16V 144-16V-az 144-16V-el -
W8IO-UR5EAZ-16V*16.94-0.45***36.1332.132.39.85W8IO-UR5EAZ-16V144-16V---
W8IO-144-15FD 16.81 -0.57** 32.33 27.11 32.3 9.85 W8IO-144-15FD W8IO-144-15FD 144-15FD-az 144-15FD-el -
YU7EF EF0215 17.0 -0.46 23 25.6 33 10.06 YU7EF-EF0215 EF0215 EF0215-az EF0215-el -
M2-2M5WL 16.94 -1.22 25 21.5 33 10.07 M2-2M5WL 2M5WL 2M5WL-az 2M5WL-el $349.95
KF6A-144-17 17.09 -0.66 26.2 25.11 34.64 10.56 KF6A-144-17 KF6A-144-17 144-17-az 144-17-el -
W8IO-144-17V17.11-0.27***35.4832.3434.810.6144-17V144-17V144-17V-az144-17V-el-
M2-18xxx 17.34 -0.60 26 22 36.5 11.11 M2-18XXX M2-18XXX 18XXX-az 18XXX-el $439.95
KF6A-144-18 17.39 -0.38 26 25 37 11.3 KF6A-144-18 KF6A-144-18 144-18-az 144-18-el -

The antennas shown in red are experimental and have not yet been built or tested. The antennas shown with * have complete instructions for building. F/R includes all backlobes. Models ending in "V" have a "V" shaped driven element. Models ending in "U" have a "U" shaped reflector.  Models ending in "FD" have a horizontal folded dipole as the driven element.

# These G/T values are calculated based on stacking distances of  4.0m (E-plane) and 3.8m (H-plane).

## These G/T values are calculated based on stacking distances of  4.2m (E-plane) and 4.0m (H-plane).

* These G/T values are calculated based on stacking distances of  4.4m (E-plane) and 4.2m (H-plane).

** These G/T values are calculated based on stacking distances of  4.6m (E-plane) and 4.4m (H-plane).

*** These G/T values are calculated based on stacking distances of  4.8m (E-plane) and 4.6m (H-plane).

Cushcraft, Hy-Gain and M2 antennas can be purchased through many US dealers.  The K1FO antennas can be purchased through Directive Systems.  The G0KSC LFA Yagis can be purchased through Innovantennas-US or through Force-12 (these are shipped from England).  DK7ZB antennas may be purchased through VPA Systems.


222 MHz long boom Yagi NEC files (17-33 foot booms)

Model Directive Gain (dBi) YagiCAD
G/T (dB)
E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file YagiCAD file Az Pattern Elev Pattern Best US  Price
(Apr 28)
KF6A-222-13 16.26 -3.79 25.7 23.6 17.35 5.288 KF6A-222-13 KF6A-222-13 KF6A-222-13 KF6A-222-13az KF6A-222-13el -
KF6A-222-15 16.84 -3.07 25.3 25.3 20.64 6.29 KF6A-222-15 KF6A-222-15 KF6A-222-15 KF6A-222-15az KF6A-222-15el -
M2-222-5WL 17.45 -2.94 20.9 20.9 23.25 7.05 M2-222-5WL M2-222-5WL M2-222-5WL M2-222-5WLaz M2-222-5WLel $239.95
W8IO-222-19V17.58-37.7636.2825.877.887W8IO-222-19VW8IO-222-19VW8IO-222-19VW8IO-222-19VazW8IO-222-19Vel-
W8IO-222-17 17.94 -1.82 24.8 24.8 26 7.932 W8IO-222-17 W8IO-222-17 W8IO-222-17 W8IO-222-17az W8IO-222-17el -
K1FO-222-22 18.03 -1.64 22.38 22.37 28 8.483 K1FO-222-22 K1FO-222-22 K1FO-222-22 K1FO-222-22-az K1FO-222-22-el TBD
W8IO-222-1818.14-1.7130.928.727.68.43W8IO-222-18W8IO-222-18W8IO-222-18
W8IO-222-18azW8IO-222-18el-
W8IO-222-1918.12-1.3729.0528.4230.09.1W8IO-222-19W8IO-222-19W8IO-222-19W8IO-222-19azW8IO-222-19el-
M2-222-7WL18.65-1.1225.6525.4432.459.89M2-222-7WLM2-222-7WLM2-222-7WLM2-222-7WLazM2-222-7WLel$353.99

The antennas shown in red are experimental and have not yet been built or tested. F/R includes all backlobes. For the YagiCad G/T, Tsky=70 and Tearth = 600.

Cushcraft and M2 antennas can be purchased through many US dealers.  The K1FO antennas can be purchased through Directive Systems.


432 MHz long boom Yagi NEC files (17-30 foot booms)

Model Directive Gain (dBi) VE7BQH
G/T (dB)
YagiCAD
G/T (dB)
E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file YagiCAD
File
Az Pattern Elev Pattern Best US Price (Apr 28)
K1FO 432-25 18.64 - 3.49 23.9 23.9 16.7 5.1 FO-25-432 FO-25-432 FO-25-432 FO-25-432-az FO-25-432-el $235.95
KF6A-432-22 18.51 (9.37) - 31.3 31.3 17 5.2 KF6A-432-22 KF6A-432-22 KF6A-432-22 - KF6A-432-22el -
YU7EF EF7021 18.77 9.41 3.88 29.4 27.8 17.4 5.3 EF7021 EF7021 EF7021 EF7021-az EF7021-el -
M2 432-9WLA 19.62 - 3.76 29.4 28.9 21 6.3 9WLA 9WLA 432-9WLA M2-432-9WLA-az M2-432-9WLA-el $239.95
KF6A-432-27 19.72 10.77 5.08 33.08 31.69 23.36 7.12 KF6A-432-27 KF6A-432-27 KF6A-432-27 KF6A-432-27-az KF6A-432-27-el -
WB0DGF Hy-Gain 7031DX 19.74 - 4.35 27.6 27.0 23.72 7.23 7031DX 7031DX 7031DX 7031DX-az 7031DX-el $194.95
YU7EF EF7027 19.58 10.39 4.76 29.5 29.5 23.75 7.2 EF7027 EF7027 EF7027 EF7027-az EF7027-el -
W8IO-432-28 19.69 - 4.89 32.7 30.8 24.6 7.5 W8IO-432-28 W8IO-432-28 W8IO-432-28 W8IO-432-28az W8IO-432-28el -
K1FO 432-33 20.07 10.93 5.14 23.4 23.4 24.1 7.35 FO-33-432 FO-33-432 FO-33-432 FO-33-432-az FO-33-432-el $299.95
M2 432-13WL20.530.33

The antennas shown in red are experimental and have not yet been built or tested.  F/R includes all backlobes. For the YagiCad G/T, Tsky=20 and Tearth = 350.

902 MHz long boom Yagi NEC files (6-20 foot booms)

Model Directive Gain (dBi) G/T E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file Az Pattern Elev Pattern Best US  Price
M2-902-17 17 - 25 - 6 - - - - - $73

These antennas have been built, tested and are currently in use.


1296 MHz long boom Yagi NEC files (10-20 foot booms)

Model Directive Gain (dBi) G/T E-F/R (dB) H-F/R (dB) Boom Length (feet) Boom Length (m) NEC file EZNEC file Az Pattern Elev Pattern Best US  Price
M2-23cm35 20.94 - 25 - 10 - - - - - $249.95

These antennas have been built, tested and are currently in use.

The performance numbers listed in the tables above are from my NEC2 and NEC4 simulations except for the G/T values, which come from VE7BQH's tables. These numbers will vary slightly due to factors such as element segmentation density and losses due to aluminum conductivity.


Element Length Correction due to Boom

The VHF/UHF antenna NEC files shown above include the "raw" element lengths.  That is, the element lengths are those used with a wood or plastic (dielectric) boom or supported above or below a metal boom with an large insulator. To convert these raw lengths into actual lengths used when passed through the center of metal booms, you need to add a correction factor, based on whether the element is insulated and passes through the center of a metal boom, or is shorted directly to the metal boom with a clamp. If the element is insulated when it passes through the metal boom, the correction factor is approximately 15% the diameter of the boom. For example, for a 36" (raw length) insulated element passed through the center of a 1" metal boom, the YU7EF correction factor is 0.15", so the actual length should be 36.15" when built.  The table below gives correction factors for common US boom diameters.

144 MHz
Boom Diameter (inches)DL6WU/G3SEK insulated element THRU
metal boom correction factor (inches)
YU7EF insulated element THRU metal
boom correction factor (inches)
YU7EF insulated element ABOVE metal
boom correction factor (inches)
0.8750.1060.1250.031
1.0000.1370.1500.0375
1.1250.1700.1880.047
1.2500.2060.2150.0538
1.3750.2460.2550.0638
1.5000.2890.2950.0738
1.6250.3330.3400.085
1.7500.3800.3850.096

Various antenna experimentors have similar correction factors, as shown below.

Here is a link to YU7EF's Boom Correction Notes.

Here is a link to YU1AW's Boom Correction article.

Here is information from the VHF/UHF Long Yagi Workshop.

Here is a link to DG7YBN's Boom Correction Notes and his Practical Yagi Building page.

Here is a link to SM5BSZ's collection of Boom Correction information.

The plastic element insulators and stainless steel keepers may be purchased from Directive Systems here in the US.

Here are some ideas and hints to help with your home antenna construction.


Comments and corrections/additions are welcome!

contact Roger: email to 

rgcox2 (at) gmail.com

Roger Cox W8IO - Spring Lake, MI