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 YBN 22w
A 50 ohms direct feed 2 ele. Yagi with high potential
as broad beam Contest Stack. See yourself and compare to DJ9HO Double Quads and 7ZB Oblongs. Full details on 2 and 4 Yagi
stacks are given 3D Pattern of 4 x Stack
 YBN 25m (58)
1.6 m high F/R, good willing 50 ohms
direct feed Yagi as introduced with bent DE short version of the 58 in Dubus 4/2012 Elevation Plot
 YBN 28m (58)
3.6 m nice G/T, good willing 50 ohms
direct feed Yagi as introduced with bent DE expanded version of the 58 in Dubus 4/2012
Actually it seems to be so good that DK7ZB decided to use it as draft for the 8 ele. OWM he just published.
Elevation Plot
 YBN 210w (58)
5 m wide band, good willing 50 ohms
direct feed Yagi as introduced with straight DE expanded version of the 58 in Dubus 4/2012
Elevation Plot
 GTV 27n
3.1 m narrow band, max. G/T version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 28w
3.7 m wideband, still good G/T and nice F/B version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 28n
3.8 m narrow band, max. G/T version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 29n
4.3 m narrow band, balanced between low Antenna Temp. and G/T version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 YBN 210w 12.5 Ω
5.1 m  144.0 to 144.8 MHz wide band 12 ohms OWLstyle
Low Noise Yagi with straight DE and very low back lobes only Elevation Plot
 GTV 210LT
5.1 m moderate band width, lowest Antenna Temp. version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 211LT
6.0 m moderate band width, lowest Antenna Temp. version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 YBN 212w 12.5 Ω
6.8 m wide band 12 ohms OWLstyle
Low Noise Yagi with straight DE and very low back lobes only Azimuth Plot:
 GTV 212m mk2
Improved 6.8 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot:
 GTV 212n
6.8 m narrow band version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot:
 GTV 214w
8.4 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 216w
10 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 219m
12.4 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot

....... 
Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking
Contest 4 Yagi Stack
YBN 25m Yagi with Conventional Driver (Split or Folded Dipole)
This little Yagi has a high F/B, which makes it quite useful as a contest stack,
because the clean rear pattern is kept with stacked arrays.


The YBN 25m is the very pilot model which was used to derive
all the "OnBoomBCFactors" from (s. Dubus 2/2010). It has been
measured about 50 times using various boom dimensions and
element lengths. Finally for the 58 Yagi concept article (Dubus
4/2012) with folded dipole too.
If you stick to the dimensions I give below
and use the right i.e. measured symmetrising coax length
you virtually can not fail with your build.
On right : Stagger stacked 2 x 5 ele. (s. Dubus 1/2014)



Sketch of boom with option to expand to 8 elem. / The additional 200+ mm on the rear enable mounting it formast as on
photo on left side. Note differing position of D1 when using thin through boom elements or folded dipole as given below.
Performance Data
Elem. 4 mm Elem. 5 mm Elem. 8 mm
Gain vs. isotr. Rad. 10.2 dBi 10.2 dBi 10.2 dBi
Gain vs. Dipole 8.0 dBD 8.0 dBD 8.0 dBD
3 dB Hplane 73.0 deg. 72.8 deg. 73.2 deg.
3 dB Eplane 54.8 deg. 54.6 deg. 54.8 deg.
F/B 24.9 dB 25.2 dB 24.8 dB
F/R 23.4 dB 23.4 dB 23.0 dB
Impedance 50/200 ohms = =
Mechan. Length 1485 mm = =
Electr. Length 0.74 λ = =
Stacking Dist. hpol.
toptobottom 1.57 m
sidebyside 2.03 m
Geometry
EZNEC wires for 8 mm elements
INSULATED THROUGH BOOM THIN ELEMENTS (BC acc. 6WU)
Pos. 1/2 Length BC 20 mm BC 20 mm BC 25 mm BC 1"
in NEC = 2.2 = 2.2 = 3.4 = 3.5
Refl. 0 514.5 1033.2 1031.2 1032.4 10xx.x
DE 283 496.0 994.2 994.2 995.4 9xx.x
D1 403 480.0 966.2 962.2 963.4 9xx.x
D2 822 467.5 942.2 937.2 938.4 9xx.x
D3 1485 433.5 875.2 869.2 870.4 8xx.x
ele.Ø 5 mm 4 mm 5 mm 5 mm 1/4"
Use WiMo made spare Folded Dipole for their YU7EF line EF0208c
or selfmade one with modified D1 as follows:
Note: for elements 4 mm D1 is of differing length for 5 and 8 ele. Yagi when using a folded DE
ele. 4 mm, Pos. 403 mm, NEC => 483.0, 20x20 => 968.2, 25x25 => 969.4 mm
ele. 5 mm, Pos. 402 mm, NEC => 481.0, 20x20 => 964.2, 25x25 => 965.4 mm, 1"x1"=> 96x.x
ON BOOM ELEMENTS
Pos. 1/2 Length BC 15x15 BC 20x20 BC 25x25 BC 1x1"
in NEC = 2.7 = 3.9 = 7.6 = 7.9
Refl. 0 514.5 1031.7 1032.9 1036.6 1034.9
DE 283 496.0 994.7 995.9 999.6 999.9
D1 403 475.0 952.7 953.9 957.6 954.3
D2 822 461.0 924.7 925.9 929.6 925.9
D3 1485 423.8 850.3 851.5 855.2 851.5
ele.Ø 8 mm 8 mm 8 mm 8 mm 3/8"
Note: element lengths for Ø 8 mm fit 5/16" too
The Driver Dipoles diameter is 10 mm for all examples.
Use EZNEC's AutoSegmentation at 144.3 MHz.
Use WiMo made Folded Dipole (spare from YU7EF line EF0208c)
or selfmade one with modified D1 as follows:
NEC => 477, Boom 20x20 => 957.9, Boom 25x25 => 961.6 mm, Boom 1"x1"=> 961.9
Folded Dipole
Folded DE tiptotip = 990, inner height = 54, diam. = 10 for all builds
Sketch of Folded Dipole
Overview on the stages of the YBN 5 5 / 8 / 10 ele. project
Here is a very helpful overview on the stages of the YBN 5 5 / 8 / 10 ele. project provided by Stef, F4EZJ (tnx!).
It shows what elements are shared and different at what positions on the boom for the various combinations
Note: Element lengths given fit elements mounted on a 20 x 20 mm boom with 'standard insulators and M3 screw
Pattern and VSWR Plots
Current distribution
Elevation and Azimuth plot at 144.3 MHz
RL and SWR plot  Version with Folded Dipole from WiMo EF0208c
miniVNA: 144.40 MHz, Z = 49.6 Ohm, SWR = 1.03, RL = 36 dB
Note: this plot is taken on a build without any post tuning on DE or D1.
Just the "OnBoomBC" added.
Downloads
EZNEC file of this Yagi with Straight Split DE
Read more about building this Yagi in my Article "58 ... an extendable 144 MHz Yagi" in Dubus 4/12
Stacking
Stacking Dist. DL6WU Formula min. Side Lobes max. F/B
Hplane 1.57 m 1.41 m 1.90 m
Eplane 2.03 m 1.83 m 2.01 m
Data of 5 over 5 ele. Yagi stack using DL6WU stacking distances 10%
Gain vs. isotr. Rad. 12.7 dBi
Gain vs. Dipole 10.6 dBD
F/B 18.5 dB
T_ant 236,0 K*
G/T 11,01 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by Hframe included
Data of 4 bay 5 ele. Yagi stack using DL6WU stacking distances 10%
Elevation plot
Stacking Dist. DL6WU 10% DL6WU
Gain vs. isotr. Rad. 15.8 dBi 16.1 dBi
Gain vs. Dipole 13.7 dBD 14.0 dBD
F/B 21.3 dB 24.3 dB
F/R 26.2 dB 24.3 dB
T_ant 231 K* 237 K*
G/T 7.85 dB* 7.64 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by Hframe included
(*) T_sky = 200 K, T_earth = 1000 K as in VE7BQH G/T table
Elevation plot and data of 4 Yagi vertcal bay using distances for max. F/B
Simulated over perfect ground
Free Space Data Over perfect gnd
Gain vs. isotr. Rad. 16.25 dBi 20.9 dBi
Gain vs. Dipole 14.10 dBD 18.8 dBD
F/B 27.5 dB 26.1 dB
Theoretical numbers, no phasing line losses
nor imperfections caused by Hframe included
Stagger Stacked Contest Array
These Yagis are stacked at 1.90 m and upper & lower Yagi in put 502 mm backwards.
The actual shift for this design stack of 502 mm is a little less than the principle 1/4 λ on 144.3 MHz.
Same as the proposed stacking distance of 1.90 m differs from the 1.57 m per DL6WU formular.
Why is that so?
The principle 1/4 λ is a number based on the theoretical concept of canceling backwards
source by a total of 180° of phase shift. But the individual directive YagiUda antenna holds
phase shifts between parasitic elements and exciter (dipole) in itself. Thus best results for
increased F/B and F/R vary slightly. Same to the difference in vertical stacking distance to DL6WU.
A stacked arrays pattern is an intereference pattern of 2 or more sources i.e. Yagis. A stacking
scheme and goals apart from the standard longs for other optimum stacking distances.
Read abt. the principle here: Article 'Stagger Stacking' by Bill Thompson as PDF
Photo: 4 x YBN 25m stacked at 1.90 m vertical and 502 mm inner shift
Free Space Elevation Plot of Stagger Stacked 4 x vert. YBN 25m
Free Space Azimuth Plot of Stagger Stacked 4 x vert. YBN 25m
How to feed?
This idea goes back to Robi, S53WW's
"High Performance Antenna Stack for 2m Contest&Tropo Work", here .
Read S53WW's web article or my article published in Dubus 1/2014 & Dubus Technik XIII for
full details of theory about stagger stacking and feeding with 1/4 λ phase lag into
the front Yagis. Note  line lenghts given hold no errors here, but a creative and proven
use of the periodicity of the sinus wave
Image Source Dubus 1/2014: DG7YBN, Stacking beyond DL6WU  Part 2
These are 50 ohms coaxes, all of them, transformation and phasing is done
by the lenghts only, there is NO power splitter needed.
Basics
The inner Yagis are displaced by 1/4 λ. To compensate this the feeding coaxes for the
inner Yagis must be are arranged for a phase lag of 90° compared to the outer Yagis. We will
name that phase correcting length 'Lplus'.
But: Feeding with a phase lag of 270° makes +90° as 360°  270° = + 90° (periodicity of the sinus wave)
Prolonging the lines for the outer Yagis by 270° has same effect as feeding the inner Yagis with 90°.
So that instead of increasing the lengths of coax towards the inner Yagi by 90° of phase angle or 1/4 λ and
have those extra lengths hanging about on the pole with this little trick we can fit the 270° into the
lengths to the outer Yagis.
Phasing Coax Lengths
L_plus:
We name that extra 270° length as L_plus in the sketch above. With a vfactor of 0.662 for PE coax it
is 1.031 m. The reason for this is to derive shortest possible feed lines up the pole instead of winding up phasing
lines for the inner Yagis as we see so often on vertical stacks.
L_1:
L1 lengths are basically ANY length; but stay clear from any multiple of 1/4 λ x velocity factor.
L_2:
L2 lengths are basically ANY odd multiples of 1/4 λ x velocity factor. Here they are 5 x 1/4 λ x Vfactor.
At the sum point between 2 Yagis of 50 ohms impedance we find 25 ohms. Any odd multiple of 1/4 λ x velocity factor
brings that back to 50 ohms in the centre feed point. No splitter needed.
Total Lengths
Total lengths must include the lenghts inside likewise the NTjoiners or whatever self made Tjunctions.
Velocity Factor
Lengths L_plus, L1 and L2 given are for PE coax only!
For foam and air coax the effective velocity factor of these at 144 MHz must be applied.
See here Symmetrising / Transformation Lines
and here Phasing & Matching Lines
Using 3 NTPieces a flexible, easy to produce phasing line assembly is done at low costs.
73, Hartmut, DG7YBN

