Performance Data and Geometry
Pattern and VSWR
Download as File
GTV 50-10LT with bent Driven Element
This Longyagi has a high F/B and altogether very little back lobe volume
The bent DE (K6STI style) transforms from low impedance to 50 ohms at feed point for direct feed.
The name "LT" reminds of the EF0210LT by YU7EF. This design here has slightly higher Antenna Temperature only
but more gain.
A serious DX and EME Long Yagi that will deliver even in very difficult RX situatons.
Gain vs. isotr. Rad. 14.5 dBi Gain vs. Dipole 12.4 dBD -3 dB H-plane 36.0 deg. -3 dB E-plane 39.4 deg. F/B -28.1 dB F/R -26.0 dB Impedance 50 ohms Mechan. Length 14,550 mm Electr. Length 2.43 λGeometry
Use EZNEC's Auto-Segmentation at 125 MHz.
The Drivers diameter is 3/4 inch, elements are 5/8 inch
Refl DE D1 D2 D3 D4 D5 D6 D7 D8 Pos. 0 820 1207 1954 3365 5220 7500 9856 12266 14550 Ele. 2952 2868 2772 2748 2680 2637 2586 2568 2514 2458 Diam. 5/8 3/4 5/8 5/8 5/8 5/8 5/8 5/8 5/8 5/8
Difference between simulation using high segmentation as given above and low segmentation per "Auto Segmentation" at 50.15 MHz
makes a delta of 0.1 MHz. With 16 mm per MHz on 50 MHz we need to add 1.6 mm to the ele. lengths in this table to compensate the SBC.
Now we add the common BC on top of that and build a Yagi that is on correct frequency.
BC? .. really depends on way of fastening elements. For any as low as approx. 3 mm on-boom holders at 40 mm
square boom this is around 7 mm on 50 MHz. Of coarse drastucally reduced using higher not too wide holders
or round boom tubes. Call in if you want to build this Yagi and I see how I can help sorting
the boom correction with you.
Boom? For making a 'lightweigth version' the boom could be 'tapered' from square tube
1 x 4.7 m long 50 x 50 x 5 mm mid section
2 x 3.0 m 40 x 40 x 5 inter section plus 0.15 mm insertion length
2 x 2.0 m 30 x 30 x 4 mm outer parts plus 0.15 mm insertion length
plus adding a bit of supporting ropes as shown on my Building Pages here
Pattern and VSWR Plots
Elevation and Azimuth plot at 50.15 MHz
RL and SWR plot - simulated
EZNEC file of this Yagi (5/8 in ele.)
73, Hartmut, DG7YBN