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).

---

How many VHF operators have been looking up this design since Dec. 2020?

---

Geometry

---

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

---

Downloads

None so far.

---

73, Hartmut, DG7YBN