A long 23 cm Yagi that provides a very clean pattern and almost 19 dBi of gain.
This is the scaled version of the 70 cm band GTV 70-25m. Design date of issue: 2020.12.29

GTV23-25m by ZS6JON under trimming and testing for best Return Loss (click to image to enlarge):

---

GTV 23-25m 3D pattern plot at 1296.2 MHz

Performance Data

Specs: with 3.2 mm elements @ 1296.2 MHz

Gain vs. isotr. Rad.  19.0 dBi
Gain vs. Dipole       16.8 dBD
-3 dB E-plane         22.2 deg.
-3 dB H-plane         22.8 deg.
F/B                  -37.7 dB
F/R                  -32.5 dB
Impedance               50 ohms
VSWR Band Width       1.05:1 *
Mechan. Length        1940.1 mm plus 2 x 70 mm offset
Electr. Length        8.39 λ

Stacking Dist. h-pol. (1296.2 MHz)
top-to-bottom         0.585 m or 1.92 ft
side-by-side          0.601 m or 1.97 ft

*) at 1300.0 MHz

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

---

Geometry

---

This Yagi with 3.2 mm elements

Ele. 3.2 mm DE 4.0 mm Boom 7.5 x 7.5 mm ABS Plastic Ele. fastening &. photo acc. F4FEY

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


Coming soon ...


The Drivers diameter is 4 mm.
The EZNEC model is done with Auto-Segmentation at 1296.2 MHz

---

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: 70 mm Offset front: 70 mm

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

The Drivers diameter is 4.763 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 SWR plots - simulated

Return Loss and SWR plots, same span 1150-1350 MHz as plotted - simulated

GTV23-25m plot 1150-1350 MHz by ZS6JON: Return Loss (dB)

GTV23-25m plot 1150-1350 MHz by ZS6JON: VSWR

GTV23-25m plot 1150-1350 MHz by ZS6JON: Smith Chart

---

Downloads

None so far.

---

73, Hartmut, DG7YBN