VHFUHF Long Boom, High Performance Antenna Designs by W8IO
(links updated 12 Aug 2017)
This page documents the various long boom VHFUHF antenna designs that I have created. Some are entirely new designs and others are optimized versions of popular Ham designs. The entirely new antenna designs are called Loggi's. More information on the Loggi design can be found here. The optimized designs are typically popular VHF long Yagi designs that I have peaked for F/R greater than 30 dB in both the E and H planes. If possible to achieve in the same design, I will also try to improve the first sidelobe levels in both planes. Usually, these optimizations are associated with a slight decrease in forward gain (less than 0.1 dB).
Model  Directive Gain (dBi)  G/T  EF/R (dB)  HF/R (dB)  Boom Length (feet)  Boom Length (m)  NEC file  EZNEC file  Az Pattern  Elev Pattern 
Loggi14427A1  16.05  1.47  38.27  32.68  25.85  7.88  14427A1       
Loggi14427A5  16.19  1.29  34.98  34.03  25.85  7.88  14427A5       
W8IOLP14422  14.3    35  35  22    LP14422  LP14422  LP14422az  LP14422el 
W8IOLP14435MAXFB  16.34    48  37  32  9.7  LP14435MAXFB  LP14435MAXFB  LP14435MFBaz  LP14435MFBel 
 
 
   
   
      
                   
W8IO 50 MHz long boom Yagi and LPDA data (1645 foot booms)
Model  Directive Gain (dBi)  +/ Gain (DL6WU equation)  EF/R (dB)  HF/R (dB)  ESLL (dB)  HSLL (dB)  Boom Length (feet)  Boom Length (m)  Boom Length (lambda)  NEC file  EZNEC file  Az Pattern  Elev Pattern 
Loggi507  11.09  +0.42  25.7  20.35  none  20.1  16  4.81  0.8  Loggi507       
Loggi508  11.69  +0.54  23.27  23.27  30  16.6  18  5.53  0.92  Loggi508       
LP509FB  11.77  0.46  34.38  28.23  none  24.6  24.8  7.57  1.27         
Loggi509  12.25  +.01  31  22.7  31.5  19.9  24.9  7.6  1.28  Loggi509       
The antennas shown in red are experimental and have not yet been built or tested. F/R includes all backlobes.
The DL6WU gain curve can be written as GAIN (dBi) = 7.773 * LOG (Length / Lambda) + 11.43
W8IO 144
MHz long boom Yagi data (2042 foot booms)
Model  Directive Gain (dBi) 
4 bay G/T (dB) 
+/ Gain (DL6WU equation) 
YagiCAD G/T (dB) 
EF/R (dB)  HF/R (dB)  ESLL (dB) 
HSLL (dB) 
Boom Length (feet)  Boom Length (m)  Boom Length (lambda) 
NEC file  EZNEC file  Az Pattern  Elev Pattern 
W8IO14412V  15.63    +0.20    33.15  27.54    17.0  22.3  6.8  3.27  14412V       
W8IO14413V  16.01    +0.18    34.68  28.85  21  17.3  25.1  7.65  3.68  14413V       
W8IO14414V*  16.27  1.18*  +0.18    34.06  30.04  21.2  17.7  27.16  8.28  4.0  14414V  14414V  14414Vaz  14414Vel 
W8IO14414V2  16.27    +0.18    35  31  21.1  17.6  27.16  8.28  4.0         
W8IO14415V  16.58  0.80**  +0.15    34.33  31.53  20.7  17.5  30.0  9.14  4.4  14415V  14415V  14415Vaz  14415Vel 
W8IO14415FD  16.81  0.57**  +0.14    32.33  27.11  23.2  20.5  32.3  9.85  4.73  14415FD  14415FD  14415FDaz  14415FDel 
W8IO14416V  16.87  0.55**  +0.20    35.8  32.3  19.6  16.8  32.3  9.86  4.73  14416V  14416V  14416Vaz  14416Vel 
W8IOUR5EAZ16V*  16.94  0.45***  +0.27    36.15  32.18  19.2  16.4  32.3  9.85  4.73  W8IOUR5EAZ16V  14416V     
W8IO14417V  17.11  0.27***  +0.18    35.48  32.34  19.2  16.5  34.8  10.6  5.1  14417V  14417V  14417Vaz  14417Vel 
W8IO14418V  17.29  0.09***      35.54  32.69  18.7  16.2  37  11.3  5.43  14418V  14418V  14418Vaz  14418Vel 
W8IO14418V2  17.42  0.07***  +0.28    34.08  30.07  17.9  15.5  37  11.3  5.43  14418V2  14418V2  14418V2az  14418V2el 
W8IO14419V  17.62  +0.17***  +0.234    34.81  32.37  17.9  15.6  39.9  12.15  5.84  14419V  14419V  14419Vaz  14419Vel 
W8IO14420V  17.87  +0.36***  +0.28    37.04  31.63  17.7  15.6  42  12.9  6.2  14420V  14420V  14420Vaz  14420Vel 
The antennas shown in red are experimental and have not yet been built or tested. These are all optimized versions of popular Ham designs. The antennas shown with * have complete instructions for building. 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. F/R includes all backlobes. For the YagiCAD G/T, Tsky=200 and Tearth = 1000.
# These G/T values are calculated based on stacking distances of 4.2m (Eplane) and 4.0m (Hplane).
* These G/T values are calculated based on stacking distances of 4.4m (Eplane) and 4.2m (Hplane).
** These G/T values are calculated based on stacking distances of 4.6m (Eplane) and 4.4m (Hplane).
*** These G/T values are calculated based on stacking distances of 4.8m (Eplane) and 4.6m (Hplane).
The DL6WU gain curve can be written as GAIN (dBi) = 7.773 * LOG (Length / Lambda) + 11.43
Another good gain curve for yagis is given by Tom Ring, WA2PHW/K0TAR: Gain (dBd) = 10 * LOG (5.4075 * (Length/Lambda) + 4.25)
W8IO 222 MHz long boom Yagi data (1935 foot booms)
Model  Directive Gain (dBi) 
4 bay
G/T (dB)

+/ Gain (DL6WU equation) 
YagiCAD G/T (dB) 
EF/R (dB)  HF/R (dB)  ESLL (dB) 
HSLL (dB) 
Boom Length (feet) 
Boom Length (m) 
Boom Length (Lambda) 
NEC file  EZNEC file  YagiCAD file  Az Pattern  Elev Pattern 
W8IO22215V  16.61  +3.23**  +0.18    34.39  31.3  20.6  17.6  19.5  5.9  4.4  W8IO22215V  W8IO22215V  W8IO22215V  W8IO22215Vaz  W8IO22215Vel 
W8IO22216V  16.9  +3.53**  +0.22    35.71  31.48  19.6  16.9  21  6.4  4.74  W8IO22216V  W8IO22216V  W8IO22216V  W8IO22216Vaz  W8IO22216Vel 
W8IO22217V  17.15  +3.84**  +0.22    34.77  31.76  19.1  16.9  22.56  6.88  5.1  W8IO22217V  W8IO22217V  W8IO22217V  W8IO22217Vaz  W8IO22217Vel 
W8IO22218V  17.33  +4.13***  +0.19    35.54  32.69  18.6  16.3  24  7.33  5.43  W8IO22218V  W8IO22218V  W8IO22218V  W8IO22218Vaz  W8IO22218Vel 
W8IO22219V  17.58  +4.41***  +0.20    37.76  36.28  18.0  15.8  25.87  7.887  5.84  W8IO22219V  W8IO22219V  W8IO22219V  W8IO22219Vaz  W8IO22219Vel 
W8IO22220V  17.90    +0.31    35.55  31.09  17.6  15.7  27.46  8.37  6.2  W8IO22220V  W8IO22220V  W8IO22220V  W8IO22220Vaz  W8IO22220Vel 
W8IO22217  17.94    +0.53  1.82  24.8  24.8  21.3  19.5  26  7.932  5.875  W8IO22217  W8IO22217  W8IO22217  W8IO22217az  W8IO22217el 
W8IO22218  18.14  +4.60###  +0.53  1.71  30.9  28.7  20.1  18.4  27.6  8.43  6.24  W8IO22218  W8IO22218  W8IO22218  W8IO22218az  W8IO22218el 
W8IO22219  18.12  +4.82### 
+0.24  1.37  29.05  28.42  21.4  19.7  30  9.1  6.76  W8IO22219  W8IO22219  W8IO22219  W8IO22219az  W8IO22219el 
The antennas shown in red are experimental and have not yet been built or tested. F/R includes all backlobes. For the G/T, Tsky=70 and Tearth = 600.
** These G/T values are calculated based on stacking distances of 3.4m (Eplane) and 3.3m (Hplane).
*** These G/T values are calculated based on stacking distances of 3.5m (Eplane) and 3.4m (Hplane).
### These G/T values are calculated based on stacking distances of 3.6m (Eplane) and 3.5m (Hplane).
The DL6WU gain curve can be written as GAIN (dBi) = 7.773 * LOG (Length / Lambda) + 11.43
W8IO 432 MHz long boom Yagi data
(1432 foot booms)
Model  Directive Gain (dBi) 
4 bay
G/T (dB)

Stacking Distance for G/T  +/ Gain (DL6WU equation) 
YagiCAD G/T (dB) 
EF/R (dB)  HF/R (dB)  ESLL (dB) 
HSLL (dB) 
EBW (deg)  HBW (deg)  Boom Length (feet)  Boom Length (m)  Boom Length (Lambda) 
NEC file  EZNEC file  YagiCAD File 
Az Pattern  Elev Pattern 
W8IO43220V  17.98  9.18  1.85m  +0.28    33.4  30.4  16.5  14.6  14.1  4.3  6.2  W8IO43220V  W8IO43220V    W8IO43220V  W8IO43220V  
W8IO43228  19.69    2m  +0.23  4.89  32.7  30.8  23  22  24.6  7.5  10.8  W8IO43228  W8IO43228  W8IO43228  W8IO43228az  W8IO43228el  
W8IO43229  19.79  10.79  2.3m  +0.204  5.0  33.55  31.55  23.6  22.5  25.6  7.8  11.2  W8IO43229  W8IO43229  W8IO43229  W8IO43229  W8IO43229  
HyGain 7031DX  19.74  10.29  2.4m  +0.398  4.35  27.6  27.0  19.5  18.4  23.72  7.23  10.42  7031DX  7031DX  7031DX  7031DXaz  7031DXel  
W8IO43231*  19.84  10.61  2.5m  +0.498  4.66  28.46  27.78  19.3  18.4  20.5  21  23.72  7.23  10.42  W8IO43231  W8IO43231  W8IO43231  W8IO43231az  W8IO43231el 
W8IO43232*  20.03  10.49  2.3m  +0.552  30.84  27.99  18.3  17.3  20  20  24.69  7.525  10.85  W8IO43232  
W8IO43233*  20.10  10.95  2.3m  +0.519  5.12  28.01  27.96  18.8  17.9  20  20.5  25.54  7.78  11.22  W8IO43233  W8IO43233  W8IO43233  W8IO43233  W8IO43233 
W8IO43235*  20.37  11.15  2.4m  +0.543  5.33  31.31  28.32  18.6  17.6  19.2  19.6  27.37  8.34  12.03  W8IO43235  
W8IO43237*  20.64  11.42  2.4m  +0.596  5.6  30.55  28.95  18.2  17.2  18.8  19.2  29.2  8.9  12.83  W8IO43237  
W8IO43240*  21.04  11.78  2.4m  +0.692  5.96  33.0  29.09  17.2  16.4  17.8  18.0  32.0  9.74  14.04  W8IO43240 
VHFUHF
Misc Antenna Links
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.
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)

0.875  0.106  0.125  0.031 
1.000  0.137  0.150  0.0375 
1.125  0.170  0.188  0.047 
1.250  0.206  0.215  0.0538 
1.375  0.246  0.255  0.0638 
1.500  0.289  0.295  0.0738 
1.625  0.333  0.340  0.085 
1.750  0.380  0.385  0.096 
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