DG7YBN / 144 MHz / GTV 2-16w
  Last Update July 16th 2014




.......



Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking


GTV 2-16w Yagi   with bent Driven Element

144 to 146 MHz Wideband Antenna Version (OWA style)

This Yagi has very low back lobes for its length. It may serve as a single powerful antenna for Tropo and EME
or make a quiet contest antenna due to its high F/B. The bent DE (K6STI style) transforms from approx. 17 ohms to 50 ohms at feed point.

Current distribution


2015-04-17: Nice photos of GTV 2-16w and GTV70-23 m at SP8MRD on qrz.com


Performance Data

                       ele. 4 mm      ele. 8 mm
Gain vs. isotr. Rad.   16.9 dBi       16.9 dBi
Gain vs. Dipole        14.7 dBD       14.7 dBD
-3 dB H-plane          27.4 deg.      27.4 deg.
-3 dB E-plane          28.8 deg.      28.6 deg.
F/B                   -33.8 dB       -28.6 dB
F/R                   -27.5 dB       -27.4 dB
Impedance                50 ohms         =
Mechan. Length         9870 mm           =
Electr. Length         4.74 λ

Stacking Dist. h-pol.    DL6WU       max. G/T
top-to-bottom           3.62 m        4.45 m
side-by-side            3.87 m        4.60 m


Geometry

                                               
        Pos.    1/2 Length  1/2 Length    Full Length    Full Length    incl. BC & SBC
                  in NEC      in NEC      Free Space     Free Space      on 25x25 Boom
				                           
Refl.     0       5xx.0       510.0         1025.0         1020.0          1029.9
DE(b)   215      100-4xx     100-491         982.0          982.0           991.9
DE(a)   274       0-100       0-100          100.0          100.0           100.0
D1      405       4xx.5       480.5          975.0          961.0           970.9
D2      690       4xx.0       474.5          963.4          949.0           958.9
D3     1236       4xx.0       462.5          942.0          925.0           934.9
D4     1874       4xx.0       455.5          930.0          911.0           920.9
D5     2615       4xx.0       448.0          917.0          896.0           905.9
D6     3407       4xx.0       444.25         910.0          888.5           898.4
D7     4227       4xx.0       438.0          898.0          876.0           885.9
D8     5072       4xx.0       436.0          895.0          872.0           881.9
D9     5927       4xx.0       433.5          890.0          867.0           876.9
D10    6762       4xx.0       429.0          882.0          858.0           867.9
D11    7585       4xx.0       427.0          878.0          854.0           863.9
D12    8404       4xx.0       426.0          877.0          852.0           861.9
D12    9190       4xx.0       423.0          872.0          846.0           855.9
D14    9870       4xx.0       416.0          858.0          832.0           841.9
                ele. 1/4"   ele. 8 mm      ele. 4 mm      ele. 8 mm       ele. 8 mm

4 mm elements insulated through boom BC:
(1.) add the 2.3 mm of SBC as shown below
(2.) Use DJ9BV BC numbers and nylon rivets on square boom as shown on BC-page
(3.) ... or SM5BSZ's BC.exe for even more accuracy or other insulators

On Boom BC:
SegmentationBC = +2.3 mm = (144.7 MHz - 144.3 MHz) * 5.85 mm/MHz
BaseBC (25x25) = +7.6 mm for semi-insulated on boom
Total          = +9.9 mm

Note: element lengths for Ø 8 mm fit 5/16" too
				
The Drivers diameter is 10 mm for all examples.
Use EZNEC's Auto-Segmentation at 350 MHz.

Sketch of Driver Cell:








Pattern and VSWR Plots

Elevation and Azimuth plot at 144.1 MHz

 


SWR and Return Loss plots - simulated with 4nec2










Downloads

EZNEC file of this Yagi  

EZNEC file of this Yagi as over stacked 4 bay (max. G/T)  









Stacking



Stacking Dist.    DL6WU Formula    max. G/T
H-plane               4.21 m        4.45 m
E-plane               4.39 m        4.60 m

Elevation plot and data of 4 Yagi bay using DL6WU stacking distances


Gain vs. isotr. Rad.  22.85 dBi
Gain vs. Dipole       20.70 dBD
-3 dB H-plane         12.4 deg.
-3 dB E-plane         13.0 deg.
F/B                  -36.0 dB
F/R                  -28.9 dB
T_ant                221.4 K*
G/T                  -0.60 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
Elevation plot and data of 4 Yagi bay using distances for max. G/T


Gain vs. isotr. Rad.  22.94 dBi
Gain vs. Dipole       20.79 dBD
-3 dB H-plane         12.0 deg.
-3 dB E-plane         12.2 deg.
F/B                  -34.1 dB
F/R                  -28.9 dB
T_ant                222.4 K*
G/T                  -0.53 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


Flag Counter