DG7YBN / 432 MHz / YBN 70-14 plus 4 w Yagi
  Last Update Oct. 22th 2020


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Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking


YBN 70-14 plus 4 w Yagi   with straight Driven Element

Wideband version ... 430 to 440 MHz

As a very wideband Yagi it has a 4 x reflector wall fitted to acheive very low back lobes across
430-440 MHz. Simulated Return Loss (S11) is better -30 dB from 430 to 440 MHz. Due to length and whole
70 cm band coverage it may serve for anything from repeater to SSB band up to satellite operations.
Design date: Oct. 2020.

The Yagi is a 50 ohms direct feed design which of coarse also can be built with a common folded dipole.
The reflector wall follows DL6WU's way of increasing F/B on a wideband Longyagi. With this design I do
not intend to break any records regarding Antenna G/T or gain. This Yagi is intended an easy to reproduce,
always and anywhere on the band clean pattern design with a solid 16 dBi of gain.


Current distribution


3D Pattern (432.1 MHz)


Return Loss and VSWR (424 - 444 MHz)




Performance Data

Specs: with 8.00 mm elements @ 432.1 MHz 

Gain vs. isotr. Rad.  16.0 dBi
Gain vs. Dipole       13.9 dBD
-3 dB E-plane         31.8 deg.
-3 dB H-plane         34.0 deg.
F/B                  -31.0 dB
F/R                  -27.4 dB
Impedance               50 ohms
Mechan. Length        3244 mm incl. 2 x 40 mm stand off
Electr. Length        4.56 λ

Stacking dist. h-pol.
top-to-bottom         1.26 m or 4.13 ft
side-by-side          1.34 m or 4.40 ft


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Geometry




        



Table 1: 70 cm section, 8.00 mm elements on a 20 x 20 mm boom:


"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for standard insulators as sold by WiMo, Tino's Funkshop, HF Kits.nl, 7arrays:

Boom shape: square
Boom: 20 x 20 mm
Offset rear: 40 mm
Offset front: 40 mm 		 


Note: This includes an SBC of 1.28 mm

Note: This table starts with the DIPOLE!



Reflector Wall, also 40 mm offset at both ends.
The reflector wall is to be mounted at 40 mm minus height of insulators from rear end.





Table 2: 70 cm section, 5.00 mm elements on a 20 x 20 mm boom using hydraulic clamps (like Stauff) or SM7DTT insualtors:


"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for using hydraulic clamps (like Stauff) or SM7DTT insulators:

Boom shape: square
Boom: 20 x 20 mm
Offset rear: 40 mm
Offset front: 40 mm 		 


Note: This includes an SBC of 1.28 mm

Note: This table starts with the DIPOLE!



Reflector Wall, also 40 mm offset at both ends.
The reflector wall is to be mounted at 40 mm minus height of insulators from rear end.











Radiation Pattern and VSWR Plots

Elevation and Azimuth plot at 432.1 MHz (8.0 mm ele.)

 



Elevation and Azimuth plot at 434.0 MHz

 



Elevation and Azimuth plot at 436.0 MHz

 



Elevation and Azimuth plot at 438.0 MHz

 



SWR and Return Loss plots - simulated with 4nec2









Downloads

none so far








Stacking 


Stacking Dist.    DL6WU Formula
H-plane               1.26 m
E-plane               1.34 m


2 x vertical YBN 70-14 plus 4 w


Elevation Plot (432.1 MHz and 438 MHz)

  




4 x vertical YBN 70-14 plus 4 w


Elevation and Azimuth Plot (432.1 MHz)

  



Data for elements 8.00 mm @ 432.1 MHz 

Gain vs. isotr. Rad.  21.8 dBi
Gain vs. Dipole       19.7 dBD
F/B                  -29.8 dB
F/R                  -29.8 dB
T_ant                 51.4 K*
G/T                    4.77 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by mast included
*) T_sky = 27 K, T_earth = 1800 K as in newer VE7BQH G/T table

3D pattern plot with 4nec2's 3D viewer


Finally a G/Ta analysis with AGTC as MS Excel tool:
A 4 Yagi bay at DL6WU stacking distances v + h shows a corrected G/Ta of 4.77 dB at T:earth = 1800 K, T_sky = 27 K.







73, Hartmut, DG7YBN


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