Homebrew 23cm (1296 MHz) HB9CV yagi antenna for SOTA
To get the 23cm amateur started, SG-Lab’s 23cm 1296 MHz transverter is supplied with a PCB 23cm 2el HB9CV antenna. I am very happy with the performance of the PCB version, having worked Rod VK2TWR in Nimmitabel from Mt Taylor in Canberra, that’s a 130 km path with just 2.5 watts. I have seen 2m and 6m versions of the HB9CV antenna so I was keen to make my own 23cm version using brass for the boom and radiating elements. Inspiration for this project can be traced to Ernest PA3HCM for his post on a 23cm HB9CV used to access a 23cm amateur television (ATV) repeater.
This is my take on the 23cm HB9CV 2el yagi:
- 2 * 3 mm dia brass rod 120 mm long
- 6 mm square brass bar 300 mm
- Piston trimmer capacitor 3.5 pf
- Short length of 1.5 mm copper wire
- SMA elbow panel to PCB mount
- Plastic project box 129 x 78 x 43 mm (minimum size)
For dimensions see: Changpuak HB9CV online calculator
Prepare two elements as per the dimensions above. Next mark out the boom element spacings, drill two 1.5 mm pilot holes followed with a 3 mm drill bit. Next chamfer each hole then place the elements into the boom. Take care to center each element then solder the elements in place.
Piston trimmer capacitor range – 0.42 to 3.82 pf
Piston trimmer is soldered to the gamma bar corner nearest to the reflector (longest element)
Solder the SMA connector to the boom.
Cut the brass boom 5 mm behind the SMA connector. Retain the brass bar for the next homebrew antenna.
Adjust the piston trimmer capacitor for a low VSWR reading.
Cleaned up 23cm HB9CV antenna ready for mounting in a plastic project box 129 x 78 x 43 mm.
23cm HB9CV enclosed in a plastic project box
Next antenna construction project is a 23cm Bi-Quad 😉
Thanks for reading this post. Good luck with your antenna construction 🙂
Photos and drawings: © Copyright 2019 Andrew VK1AD
Published: 12 November 2017
Last Update: 27 January 2019