Performance Data and Geometry
Pattern and VSWR
Download as File
YBN 50-5w Yagi with straight split dipole
Wide-band version ... a very wide band yet relatively Low Noise Yagi that shows least
degradation with wet elements or snow on and thus easy to reproduce parameters.
If you are looking for a Yagi suitable for worst weather condx ... this one might be it.
This shorter Yagi is designed for easest reproduction, straight split DE and direct feed
with 50 ohms at feed point.
Use a large ferrite core, coax choke 'balun' made out of several windings on a close diameter ... or a grounded Quarter Wave
line for best results. Generally it does work without any symmetrising, but a test config with a click on ferrite for Analyser
plotting or simply SWR check is appreciated.
YBN 50-5w built by John, ZS6JON
This Yagi is built with 12.7 mm = 1/2 inch elements held by Stauff clamps on a 32 x 32 mm = 1-1/4 inch boom.
Plots with calibrated coax on an Anritsu MS2000 VNA:
Elem. 5/8 in + 16 mm Gain vs. isotr. Rad. 9.9 dBi Gain vs. Dipole 7.8 dBD -3 dB E-plane 56.0 deg. -3 dB H-plane 76.0 deg. F/B -25.5 dB F/R -20.3 dB Impedance 50 ohms VSWR Band Width 1.01:1 * Mechan. Length 4380 mm Electr. Length 0.74 λ Stacking Dist. h-pol. top-to-bottom 4.86 m = 15.94 ft side-by-side 6.37 m = 20.91 ft *) as in VE7BQH G/T table = at 50.50 MHz
Elements Ø12 mm:
Elements Ø5/8 inch and 16 mm:
Element and Driver diameter is 5/8 inch or 16 mm throughout.
Elements Ø5/8 inch and 16 mm Elements - On Boom - high insulators (Stauff)>
Refl DE D1 D2 D3 Pos. 0 912 1284 2600 4380 Boom 30x30mm 2954 2936 2746 2640 2450
Elements 1/2 inch:
Element and Driver diameter is 1/2 inch or 12 mm throughout.
Elements Ø1/2 inch - On Boom - high insulators (Stauff)
Refl DE D1 D2 D3 Pos. 0 912 1284 2600 4380 Boom 30x30mm 2954 2939 2759 2656.8 2472
Table: YBN 50-5w, 12.7 mm or 1/2 inch elements on a 1-1/4 inch square boom:
"Ready to saw and drill" data for elements on boom with BC acc. DG7YBN for Stauff Clamps:
Note: This includes a "Segmentation Density Correction" (SBC) of 0 mm
There is NO SBC since this Yagi is designed with low segmentation. Add just a few millimeters
of BC depending on mounting method of elements or insulators used.
DX-Expeditoners Wire Geometry
Make your Yagi on the fly out of wooden laces and thin aluminuim rods or blank or stranded wire.
• Diam. 4 mm / AWG 6 uninsulated wire => 9.83 dBi still
• Stranded wire: diam. 2 mm / AWG 12=> 9.74 dBi still
Attenzione: for a PVC wire insulation a full scaling needs to be done, it is not sufficient to just cut a fixed number of millimeters
• Stranded wire: diam. 1.38 mm = 1.5 mm2 / AWG 16 uninsulated wire => 9.66 dBi still; Attentione: D1's position has changed
Pattern and VSWR Plots
Elevation and Azimuth plot at 50.1 MHz
RL and SWR plot - simulated / 49.0 - 51.0 MHz
Elements 12 mm versions Return Loss
EZNEC file of this Yagi with 5/8" elements
EZNEC file of this Yagi as wire Yagi with 1.5mm2 ele.
Stacking Dist. DL6WU Formula H-plane 4.86 m E-plane 6.37 m
Gain vs. isotr. Rad. 12.7 dBi Gain vs. Dipole 10.6 dBD -3 dB H-plane 56.0 deg. -3 dB E-plane 33.0 deg. F/B -19.1 dB F/R -19.1 dB
73, Hartmut, DG7YBN