DG7YBN / 28 MHz / YBN 28-6n
  Last Update Aug. 19th 2020




.......




Performance Data and Geometry
Pattern and VSWR
With Ground Gain
Stacking


YBN 28-6n   with straight split Dipole

Digi Modes + SSB band 28.2 to 28.6 MHz


On 28 MHz we should less look for gain but very clean directivity, because if the band is open successful DX more or less comes down to fade out unwanted signals. If we can easily produce a signal that enables us to ping our own echo when twice (!) around the globe with less than 100 watts of output, we may pass on 0.5 dB gain. And when band is closed that little bit would not help at all.

The patterns scattering factor (dt.: Streufaktor) as ratio of all rear and side lobes against the beam lobe is what we should look for in first place.

Design date of issue: 2020.08.20


YBN 27-6n = 27.5 MHz version built by PU2TDY. His qrz: 3at282

   

Dipole bracket:







YBN 28-6n but by IZ1RFT

  



     


Size of bracket plates
Dipole: 230 x 42 x 20
Elements: 150 x 42 x 20

Matteo reports from pretest only 1 m above flat roof:
"Also today I have connected with 200 watt power of the icom 7700, stations from South America and do not believe that I have 1 meter antenna from the roof. I can't wait for it to be on the tower ..."



Current distribution




Performance Data (28.4 MHz, 16 mm el.)

Gain vs. isotr. Rad.  11.0 dBi
Gain vs. Dipole        8.9 dBD
-3 dB E-plane         50.4 deg.
-3 dB H-plane         63.0 deg.
F/B                  -21.2 dB
F/R                  -15.9 dB
Impedance               50 ohms
Mechan. Length        9598 mm
Electr. Length        0.91 λ

Stacking Dist. h-pol. (28.3 MHz)
top-to-bottom          10.1 m   or   33.1 ft
side-by-side           12.4 m   or   40.7 ft

Geometry

For building on a 40-50 mm boom, 16 mm elements insulated with hydraulic clamps like from co. Stauff:


27.5 MHz version for building on a 40-50 mm boom, 16 mm elements insulated with hydraulic clamps like from co. Stauff:


Center of Gravity

Mount at around 4500 mm from rear (incl rear and front offset of 140 mm each); 28 MHz version.


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Pattern and VSWR Plots

Elevation and Azimuth plot at 28.2 MHz

 


SWR and Return Loss plots - simulated with 4nec2

3D pattern










Radiation pattern with Ground Gain

At 12 m above perfect ground

At 12 m above perfect ground

Gain vs. isotr. Rad.  16.65 dBi at  12 deg.
Gain vs. Dipole       14.50 dBD
F/B                  -20.6 dB   at 169 deg.

At 14 m above perfect ground

Gain vs. isotr. Rad.  16.71 dBi at   8 deg.
Gain vs. Dipole       14.56 dBD
F/B                  -22.7 dB   at 170 deg.

At 17 m above perfect ground

Gain vs. isotr. Rad.  16.88 dBi at   9 deg.
Gain vs. Dipole       14.73 dBD
F/B                  -20.6 dB   at 171 deg.

At 24 m above perfect ground


Gain vs. isotr. Rad.  16.91 dBi at   6 deg.
Gain vs. Dipole       14.76 dBD
F/B                  -21.6 dB   at 174 deg.








Stacking



Elevation plot and data of 6 over 6 array at 10.1 m stacking distance


Gain vs. isotr. Rad.  13.97 dBi
Gain vs. Dipole       11.82 dBD
F/B                  -24.7 dB



Elevation plot and data of 6 over 6 array at 10.1 m stacking distance:
Lower Yagi 12 m, upper Yagi 22.1 m above perfect gnd

			 
Gain vs. isotr. Rad.  18.9 dBi at   8 deg.
F/B                  -23.3 dB  at 172 deg.


Elevation plot and data of 6 over 6 array at 6 m stacking distance:
Lower Yagi 18 m, upper Yagi 24 m above perfect gnd

			 
Gain vs. isotr. Rad.  18.8 dBi at   7 deg.
F/B                  -21.3 dB  at 173 deg.









73, Hartmut, DG7YBN



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