Post updated 29 November 2020. Driven elements are now threaded with M3 thread and the center insulator is fitted with two M3 x 20 mm brass stand off nuts.
Portable 4 element 2m (145 MHz) DL6WU Yagi for SOTA weighing 460 grams (1 lb)
- 4 metre length of 3.1 mm aluminium rod (Alucom)
- 1 metre length of 27 mm PVC water pipe
- 2 * plastic end caps
- 5 * 25 mm PPR plastic pipe clamps (ebay)
- 3 to 5 metres of RG58CU Mil Spec Coax. Length is your choice.
- 2 brass terminal connectors cut from a 10 amp terminal strip
- 8 cable ties
- Tripod quick release plate
Dimensions – 6.5 dB gain:
For storage all elements fit inside the 27 mm boom. The driven element insulator will remain clamped to the boom. Combined weight is 460 grams (1 lb), (Antenna, Coax and Tripod Mount).
25 mm PPR pipe clamps
Mounting arrangement for the Reflector, D1 and D2 elements
Driven Element mounting block preparation
Solder one length of twisted braid to the outside of each terminal connector , before securing terminal connectors with cable ties
Cut the Driven element (986 mm) in the center for two quater-wave elements each 493 mm long. Due to the extra wire soldered to each terminal connector, I had to trim 10 mm off each quarter-wave element to bring the resonant frequency up to 145 MHz.
This antenna can be held in your hand while operating a HT. For convenience I have shown the antenna mounted to a tripod. The combined weight with coax and tripod mount is 460 grams.
Once you have all elements in the correct position drill a hole through R, D1 and D2 clamps and into the boom, but don’t drill through the boom. You can insert a short length of dowel through each plastic clamp into the boom. This will ensure correct element position each time you assemble the antenna. 🙂
Please feel free to copy the design 🙂
Post Update 29 November 2020
Old versus New. The new driven element insulator is fitted with 2 M3 20 mm brass stand off nuts. Each end of the driven elements is now threaded with M3 thread.
The 20 mm brass stand off nuts increase the length of the driven element by approximately 10 mm. Therefore you must shorten each 3.1 aluminium driven element by 10 mm and recheck the VSWR.
Next apply Araldite or an epoxy glue to the brass stand nuts on the inside of the plastic clamp. Avoid getting glue inside the 3 mm brass thread.
Last Update: 29 November 2020
73, Andrew VK1AD