5 Element Yagi-Uda
antenna for 250MHz to 260MHz . September 2022
Investigating a practical and easily Yagi-Uda antenna construction
technique for VHF and UHF and also keen to have a listen to the
known pirate activity on a United States Navy communication satellite a
small 5 element Yagi-Uda antenna for 255MHz was chosen.
The goal was to develop an element mounting technique that allowed easy
installation and replacement of the elements, allow for easy
adjustment of the element attachment point on the boom while
requiring no drilling of holes into the boom. Also when the antenna
is no longer required it can be easily recycled into another
Photo 1 255MHz
Yagi mounted on repurposed tripod.
The element mounting assemble shown in Figure 1 and Photo
2 & 3 consists of a stainless steel hose clamp with 5mm stud hole drilled
in the strap and counter sunk headed set
screw mounted with the flat head against the boom as shown
in Photo 4. The hose clamp stud
mount requires no holes be drilled into the boom and allows for
infinite lateral adjustment along the boom.
The element mounting bracketshown in Photo 5 is
fabricated from 15 x 15mm aluminium channel pop riveted to the
element mounting plate. The aluminium channel is notched out so that
it mount flat against the boom and clear of the hose clamp strap.
6 shows the Completed255MHz
to Boom mounting arrangment..
Photo 2 Element to Boom
Photo 3 Element to Boom mounting
Photo 4 Stainless steelhose clamp and counter
sunk headed set screw.
Photo 5 Element mounting bracket.
Photo 6 CompletedYagi-Uda
Frequency:255 MHz, (useful from 249.9 to 260.1 MHz)