DG7YBN / 1296 MHz / GTV 23-23m
  Last Update Dec. 09th, 2023


Performance Data and Geometry
Pattern and VSWR
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GTV 23-23m  Yagi with bent Driven Element

A long 23 cm Yagi that provides a very clean pattern and 18.6 dBi of gain.
This is the scaled version of the 70 cm band GTV 70-23m. Design date of issue: 2021.09.17

GTV 23-23m 3D pattern plot at 1296.2 MHz

Performance Data

Specs: with 3/8 inch elements @ 1296.2 MHz

Gain vs. isotr. Rad.  18.6 dBi
Gain vs. Dipole       16.5 dBD
-3 dB E-plane         22.8 deg.
-3 dB H-plane         23.4 deg.
F/B                  -36.7 dB
F/R                  -30.4 dB
Impedance               50 ohms
VSWR Band Width       1.17:1 *
Mechan. Length        1746,8 mm plus 2 x 50 mm offset
Electr. Length        7.55 λ

Stacking Dist. h-pol. (1296.2 MHz)
top-to-bottom         0.570 m or 1.87 ft
side-by-side          0.585 m or 1.92 ft

*) at 1300.0 MHz


GTV 23-23m at ZS6BD

ZS6JON built 23 el. at Louis, ZS6BD.

GTV 23-23m at UA1019SWL


Igor, UA1019SWL built this 23 el. GTV using 3D printed insulators of near same dimensions as ZS6JON (7.2 mm outer diameter).

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This Yagi with 2.40 mm elements

Boom shape: -
Boom dim: -
Offset rear: 40 mm
Offset front: 40 mm

Image: Wooden/Plastic Boom or Plastic Standoff Holders

• This table holds no Boom or element Correction.
Experimenters version!

• The equivalent element diameter on 432 MHz is 7.2 mm.
• Elements may be made from 2.40 mm aluminium or copper (CuZn) welding rods.
• if using copper be aware that spray coating with clear coat will change frequency response.
• A 0.03 mm layer (30 microns) of clear coat (dielectrical constant approx. 2.8) shifts by approx. -3.5 MHz (1297 > 1293.5 MHz).
• Very thin wooden lace or high standoff holders that are also very thin may be used.

This Yagi with 3/16 inch = 4.763 mm elements

Boom shape: square
Boom dim: 5/8 x 5/8 inch
Wall thickn.: 1.6 mm
Holes in boom: 7.5 mm
Offset rear: 50 mm
Offset front: 50 mm

"Ready to saw and drill" data for mounting elements through this plastic boom:

The Drivers diameter is 5.0 mm.
The EZNEC model is done with Auto-Segmentation at 1296.2 MHz

Pattern and VSWR Plots

Elevation and Azimuth plot at 1296.2 MHz


Return Loss and VSWR plots - simulated

Return Loss, VSWR and Smith Chart - measured by ZS6JON


None so far.

73, Hartmut, DG7YBN

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