DG7YBN / 70 MHz / YBN 4m-5m
  Last Update June 27th 2021


Performance Data and Geometry
Pattern and VSWR
Download as File

YBN 4m-5m Yagi   with straight split dipole

This little Yagi has a high F/B and altogether very little back lobe volume
The design is a blueprint of the 5 ele. 144 MHz BC measurement Yagi with 50 ohms at feed point for direct feed.
With no high segmentation correction or complex radiators involved this design is pretty much a straight forward
simple building yet performing antenna. For stacking examples, patterns and data see the website of the
YBN 2-5m see here

YBN 4m-5m build by Andreas, DK2CF

This Yagi is build on a boom 25 x 25 mm.
Andreas reports a VSWR of 1:1.13 at 71.01 MHz without final trimm.

Photo Credit: DK2CF, tnx Andreas!

Performance Data

Gain vs. isotr. Rad.  10.2 dBi
Gain vs. Dipole        8.0 dBD
-3 dB E-plane         54.8 deg.
-3 dB H-plane         73.2 deg.
F/B                  -25.2 dB
F/R                  -23.3 dB
Impedance               50 ohms
Mechan. Length        3055 mm
Electr. Length        0.72 λ

Stacking Dist. h-pol.
top-to-bottom         3.58 m = 11.8 ft
side-by-side          4.64 m = 15.2 ft

No SBC needed since designed with auto segmentated wires at designated frequency => Free Space Geometry ready to apply a BC according planned style of building

The Drivers diameter is 16 mm

		Refl	 DE  	  D1	 D2	  D3
Pos.		   0	 582	 829	1691	3055
Ele.     	2118	2044	1966	1914	1766
Diam.             12      16      12      12      12

Pattern and VSWR Plots

Elevation and Azimuth plot at 70.15 MHz


RL and SWR plot - simulated


EZNEC file of this Yagi (12 mm ele.)  

73, Hartmut, DG7YBN

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