A 3 element LFA Yagi for 24MHz with a 3.9mtr boom
This is a high-gain, wideband LFA (Loop Fed Array) Yagi which covers 24.890 - 24.980MHz with an SWR of less than1.1:1. It has options with both UK/USA and European sized tube and has a 3 section taper.
This Antenna has been modelled using NEC4 and confirmed by FEKO. This is thousands of dollars of the very latest antenna design software available and the results are highly accurate. When loading into your software, you will see similar SWR but not the same. Please do not alter the model, build to these dimensions for the best results.
Contact me if you are unsure what correction (if any) you require for the element holders/stand-offs you will use or any other questions you may have or require different element diameter.
M0CTR installed a 3el 24MHz LFA
'...The LFA worked a treat and I followed your advise from the web site which worked perfectly..'
Antenna Layout and Construction:
8.51dBi @ 24.920MHz
21.17dB @ 24.920MHz
SWR: Below 1.1:1 from 24.89MHz to 24.980MHz
Gain: 10.6dBi (15.87 at 15m above real ground)
Refer to the above drawings
Antenna Dimensions for UK/USA and European sized tubing
Taper: Mid Section, 5/8 inch or 16mm tube (total length 2.40m). Outer section 1/2 inch or 13mm tube (4.40m). End sections as per below schedule and in 3/8 inch or 10mm.
Spacing End Section Length (All below sizes in Metres)
Reflector 0 .885
DE1 .819 0.311 - FEEDPOINT
DE2 1.914 0.311
D1 3.912 0.562
Adjust loop width for best SWR upon completion. Fit antenna with a 1:1 balun
Azimuth Plot of this super antenna
Elevation plot of this antenna
1 x 3el at 15m above ground
2 x 3el 5m spacing, bottom antenna 15m above group
Any questions, please ask!