Performance Data and Geometry
Pattern and VSWR
X-pol Details
Download as File
Stacking
GTV 2-11 LT Yagi with bent Driven Element
This Yagi shows quite a low Antenna Temperature and a moderate gain for its length, which altogether is leading to a
good G/T number. It may serve as a contest stack or medium size EME 4-Yagi-Bay, especially under tough RXing
conditions.The bent DE (K6STI style) transforms to 50 ohms at feed point for direct feed.
This Yagi-Uda design makes maximum use of a 6.0 m off the shelf aluminium tube as boom without compromising on any
design parameters to squeeze the electrical length into the given 6.0 m.
4 x GTV2-11LT xpol at OE3NFC
These Yagi sare built on 25 x 25 mm boom using 4 mm elements with SM5BSZ BC.exe Boom Correction,
held by 7arrays 4x6 mm insulators. Click Images to enlarge
All four Photos on courtesy of Norbert, OE3NFC. Tnx!
2 x vertical GTV2-11LT above a GTV 70-25m, all built by Edy, YO2LSP
These 2 Yagis are built on boom 25 x 25 mm using 10 mm elements (click onto images to enlarge:
Edy, YO2LSP: "
I finish and tested the new setup. It`s working great! New personal records for this location." ... tnx Edy!
2 x vertical GTV2-11LT built by YO2LSP, used in 2020 IARU ctest by YO5LD
Edy, YO2LSP: "
I completed the construction of 2x11 elements and 4x5 and was used in the IARU contest by YO5LD
who succeeded an excellent results for the YO position. - 413 QSO`s , ODX - DA0FF @ 1028 km, Total: 192.955 points.
The antenna works fantastic, in special 2x11 element system. Thank you for your work." ... tnx Edy!
GTV2-11LT built by Sergey, R7MU
Performance Data
Specs: with 8 mm elements @ 144.1 MHz
Gain vs. isotr. Rad. 15.1 dBi
Gain vs. Dipole 12.9 dBD
-3 dB E-plane 34.1 deg.
-3 dB H-plane 37.2 deg.
F/B -35.1 dB
F/R -29.7 dB
Impedance 50 ohms
VSWR Band Width 1.26:1 *
Mechan. Length 5920 mm
Electr. Length 2.85 λ
Stacking Dist. h-pol.
top-to-bottom 3.26 m
side-by-side 3.55 m
*) as in VE7BQH G/T table = at 145.00 MHz
2x GTV2-11LT xpol at HB9W
GTV2-11LT and GTV70-25m built by PA2CV
How many VHF operators have been looking up this design since May 2016?
Geometry
Ø8 mm Elements - On Boom - Dimensions (BC acc. DG7YBN)
Refl DE(b) DE(a) D1 D2 D3 D4 D5 D6 D7 D8 D9
Pos. 0 247 285 420 680 1171 1817 2594 3434 4279 5130 5920
Boom 20x20 mm 1026.2 (992.2) (100) 961.2 954.2 928.2 912.2 895.2 885.2 876.2 864.2 838.2
Boom 25x25 mm 1029.9 (995.9) (100) 964.9 957.9 931.9 915.9 898.9 888.9 879.9 867.9 841.9
SegmentationBC = +2.3 mm = (144.7 MHz - 144.3 MHz) * 5.85 mm/MHz
BaseBC = +3.9 mm for semi-insulated on boom (20 x 20 mm), 7.6 mm (25 x 25 mm)
Total = +6.2 mm (20 x 20 mm), +9.9 mm (25 x 25 mm)
Note: element lengths for Ø 8 mm fit 5/16" too
Ø10 mm Elements - On Boom - Dimensions (BC acc. DG7YBN)
Refl DE(b) DE(a) D1 D2 D3 D4 D5 D6 D7 D8 D9
Pos. 0 247 285 420 680 1171 1817 2594 3434 4279 5130 5920
Boom 20x20 mm 1020.2 (992.2) (100) 956.2 948.2 920.2 904.2 886.2 876.2 866.2 855.2 828.2
Boom 25x25 mm 1023.9 (995.9) (100) 959.9 951.9 923.9 907.9 889.9 879.9 869.9 858.9 831.9
Total-BC = +6.2 mm (20 x 20 mm), +9.9 mm (25 x 25 mm)
For Elements 10 mm on a 25 x 25 mm boom
This table is only valid for:
Boom shape: square
Boom dim: 25 x 25 mm
Offset rear: 40 mm
Offset front: 40 mm
Note: This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
The Drivers diameter is 10 mm for all examples.
The EZNEC model is done with Auto-Segmentation at 380 MHz
"Ready to saw and drill" data for mounting elements through boom with BC according SM5BSZ's BC.exe:
Note: with through Boom BC it is important to stick to the boom end offsets given below!
For Elements 3/16 inch through a 1 x 1 inch boom
This table is only valid for:
Boom shape: square
Boom dim: 1 x 1 in
Wall thickn.: 1/16 in
Holes in boom: 9.5 mm
Offset rear: 40 mm
Offset front: 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
Read abt. the SBC here
.
Same conditions boom but for Elements 1/4 inch
For Elements 6.0 mm through a 25 x 25 mm boom
This table is only valid for:
Boom shape: square
Boom dim: 25 x 25 mm
Wall thickn.: 1.5 mmn
Holes in boom: 8.0 mm
Offset rear: 40 mm
Offset front: 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
For Elements 6.0 mm through a 1 x 1 inch boom
This table is only valid for:
Boom shape: square
Boom dim: 1 x 1 inch
Wall thickn.: 1/16 in = 1.6 mmn
Holes in boom: 8.0 mm
Offset rear: 40 mm
Offset front: 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
For Elements 6.0 mm through a TAPERED BOOM 20 x 20 mm > 25 x 25 mm > 20 x 20 mm boom
This table is only valid for:
Boom shape: square
Boom dim: 20 x 20 mm > 25 x 25 mm > 20 x 20 mm
Wall thickn.: 1.5 mmn
Holes in boom: 8.0 mm
Offset rear: 40 mm
Offset front: 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
Sketch of Bent Dipole
Pattern and VSWR Plots
Current distribution
Elevation and Azimuth plot at 144.1 MHz
RL and SWR plot - simulated
GTV2-11LT Return Loss Plot by PA2CV
GTV2-11LT Return Loss Plot by OE3NFC
X-pol Details
xpol builders table 1: GTV 2-11LT, 4.0 mm elements through boom:
"Ready to saw and drill" data for mounting elements through boom with BC according SM5BSZ's BC.exe:
Note: with through Boom BC it is important to stick to the boom end offsets given below!
This table is only valid for:
Boom shape: square
Boom dim: 25 x 25 mm
Wall thickn.: 2.0 mm
Holes in boom: 6.0 mm
Offset rear: 500 mm resp. 570 mm
Offset front: 110 mm resp. 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
Read abt. the SBC here
.
Elements in h-plane
Elements in v-plane
GTV 2-11 LT xpol with 3/16 inch elements
This table is only valid for:
Boom shape: square
Boom dim: 1-1/4 x 1-1/4 inch
Wall thickn.: 1.2 mm
Holes in boom: 9.5 mm
Offset rear: 500 mm resp. 570 mm
Offset front: 110 mm resp. 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 2.3 mm
Read abt. the SBC here
.
Elements in h-plane
Elements in v-plane
Same conditions boom but for Elements 1/4 inch
Elements in h-plane
Elements in v-plane
Downloads
EZNEC file of this Yagi with 8 mm elements
EZNEC file of this Yagi with 4 mm elements
Stacking
Stacking Dist. DL6WU Formula
E-plane 3.538 m
H-plane 3.261 m
Plot and data of 4 Yagi bay using DL6WU stacking distances
Elevation Pattern
TANT screenshot
Gain vs. isotr. Rad. 21.0 dBi
Gain vs. Dipole 18.8 dBD
-3 dB H-plane 15.4 deg.
-3 dB E-plane 16.8 deg.
F/B -39.6 dB
F/R -32.8 dB
T_los 4.5 K
T_ant 222.0 K*
G/T -2.51 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by H-frame included
*) T_sky = 200 K, T_earth = 1000 K as in VE7BQH G/T table
73, Hartmut, DG7YBN