DG7YBN / 70 MHz / GTV 4m-5w
  Last Update June 23th 2013




.......



Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking


GTV 4m-5m Yagi   with bent Driven Element



This little Yagi has a high F/B and altogether very little back lobe volume
The bent DE (K6STI style) transforms from low impedance to 50 ohms at feed point for direct feed.




Performance Data

Gain vs. isotr. Rad.  10.2 dBi
Gain vs. Dipole        8.1 dBD
-3 dB H-plane         54.4 deg.
-3 dB E-plane         73.2 deg.
F/B                  -29.4 dB
F/R                  -20.5 dB
Impedance               50 ohms
Mechan. Length        3100 mm
Electr. Length        0.73 λ

Stacking Dist. h-pol.
top-to-bottom         3.59 m = 11.8 ft
side-by-side          4.68 m = 15.3 ft
Geometry



        Pos.    Full Length
                Free Space
                incl. SBC
				
Refl.     0       2053.0
DE(b)   489       2017.0
DE(a)   582        0-200
D1      964       1945.0
D2     1826       1905.0
D3     3100       1753.0
 
                ele. 12 mm

Using auto segmentation at 70.1 MHz results in best RL at 70.35 MHz.
Prolonging all elements by 5 mm leades back to aimed at 70.15 MHz.			
=> SegmentationBC = +5 mm
=> Free Space Geometry ready to apply a BC according planned style of building

The Drivers diameter is 12 mm.
Use EZNEC's Auto-Segmentation at 190 MHz.







Pattern and VSWR Plots

Elevation and Azimuth plot at 70.15 MHz

 


RL and SWR plot - simulated










Downloads

EZNEC file of this Yagi (12 mm ele.)  

EZNEC file of this Yagi as 5 over 5 stack using DL6WU stacking distance  





Stacking

Data of of 5 over 5 stack using DL6WU stacking distance 3.59 m = 11.8 ft


Gain vs. isotr. Rad.  13.2 dBi
Gain vs. Dipole       11.1 dBD
-3 dB H-plane         55.2 deg.
-3 dB E-plane         31.8 deg.
F/B                  -24.0 dB
F/R                  -23.5 dB
Theoretical numbers, no phasing line losses
nor imperfections caused by H-frame included

Elevation and Azimuth plot

 








73, Hartmut, DG7YBN


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