DG7YBN - YBN 2-7mz

Performance Data and Geometry

Phasing

Pattern and VSWR

Download as File

Stacking

4 x vertical Phased Contest Stack

YBN 2-7mz 28 Ω Yagi with straight Driven Element

A 28 ohms low Q, low noise Yagi derived from the well tested 5-8 series.
Design focus was on clean rear, as single Yagi and also when errecting vertical stacks paired with insensitivity against weather influences or slightly bent elements and such.

Operation target was a rugged, simple to build an handle while going portable and extremely simple to phase antenna for contest stacks.

With 28 ohms at feedpoint this design is suitable for a straight forward phasing cables concept as shown by OK1NOR / DG7YBN in '144 MHz seamlessly phased 4 x 28 Ohms Low Noise Yagi Stack' in Dubus 1/2023. Using 75 ohms coaxes of odd multiples of 1/4 wl we get 4 x 200 ohms at the sum point, which results in 50 ohms total.
Design date of issue: 2022.11.23

YBN 2-7mz 3D pattern plot at 144,1 MHz

• Online Article by Jindra, OK1NOR regarding the phasing scheme, building details, 3D print parts and more
https://docs.google.com/document/d/1VuFQeoNp1A_FRTOhJF6g-ddP92rVCGXSWLYaGIIz1rE/edit?invite=CJOjmf8N

Performance Data

Specs: with 10 mm elements @ 144.3 MHz


Gain vs. isotr. Rad.  12.24 dBi
Gain vs. Dipole       10.1 dBD
55-3 dB E-plane       45.0 deg.
-3 dB H-plane         53.0 deg.
F/B                  -34.1 dB
F/R                  -22.6 dB
Impedance             28 ohms
VSWR Band Width       1.23:1 *
Mechan. Length        2758 mm plus 2 x 40 mm offset
Electr. Length        1.33 λ

Stacking Dist. h-pol. (144.3 MHz)
top-to-bottom         2.331 m or 7.6 ft
side-by-side          2.718 m or 8.9 ft

*) as in VE7BQH G/T table = at 145.00 MHz

How many VHF operators have been looking up this design since March 2023?

YBN2_7mz built by OK1NOR at OL7M during MMC 2022

Building phase for a serious array of 18 YBN 2-7mz Yagis:

Dipoles with symmetrising 'Bazooka' choke:

Pre-assembling of 18 + 1 Yagis

Geometry

This Yagi with 10 mm elements on a 20 x 20 mm boom with standard insulators

Ele. 10.0 mm
DE 10.0 mm
Boom 20 x 20 mm

"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:

This Yagi with 10 mm elements on a 25 x 25 mm boom with standard insulators

Ele. 10.0 mm
DE 10.0 mm
Boom 25 x 25 mm

"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:

The Drivers diameter is 10 mm for all examples.
The EZNEC model is done with Auto-Segmentation at 380 MHz, SBC = 2.52 mm

Pattern and VSWR Plots

Elevation and Azimuth plot at 144.3 MHz

Return Loss and SWR plots - simulated

Phasing

Downloads

None so far.

Stacking


Stacking Dist.    DL6WU Formula (144.1 MHz)
E-plane               2.718 m
H-plane               2.331 m

Plot and data of 2 vertically stacked YBN YBN 2-7mz using DL6WU stacking distances -10 percent

Antenna View & Elevation Pattern

Plot and data of 3 vertically stacked YBN YBN 2-7mz using DL6WU stacking distances -10 percent

Antenna View & Elevation Pattern

Same with lowest Yagi at 9 m agl, perfect ground assumed

Plot and data of 4 vertically stacked YBN 2-7mz using DL6WU stacking distances -10 percent

Antenna View & Elevation Pattern

4 x vert. stack with lowest Yagi 9.0 m abover 'Perfect Ground'
F/B approx. -31 dB

Plot and data of 4 vertically STAGGER stacked YBN YBN 2-7mz using DL6WU stacking distances, 502mm shift

Lowest Yagi 9.0 m agl, highest Yagi 16.3 m agl.
18,3 dBi or > 16.1 dBd at close to 46 deg. HPBW in Azimuth with > -39 dB of F/B.

Elevation Pattern

4 x vert. stagger phased stack with lowest Yagi 9.0 m abover 'Perfect Ground'
F/B better -39 dB

Plot and data of classical H-shape bay of YBN 2-8mz using DL6WU stacking distances

Antenna View & Elevation Pattern

Antenna G/T:

73, Hartmut, DG7YBN