A High-Gain 6 element LFA Yagi with a 7.3 metre Boom for 50MHz
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The LFA design has a patent pending and all G0KSC designs are copyright. Any ham can build for their own use or those of a friend. Where profit or commerical gain exists, express permission of G0KSC must be sort.
Note, this LFA is not suited for location where high suppression of noise is required due to the existence of lobe elevation plane lobes. Where the best in noise suppression is required, chose a shorter 6el or a small 7el.
This antenna has been designed with performance in mind and provides optimum performance for the 7.3 metre boom length. As with all of my second generation LFA's wide bandwidth has been modelled into the antenna to ensure maximum performance without matching losses.
The 7.3m long 6el at OZ6ABA
The 7.3m 6el LFA at LZ1DP
Built my 9A9T 2011
The G0KSC 6 mtr Antenna, the 7.3 mtr long 6el LFA - installed 28th July 2009
The 6el at SP3OCC installed 2010
The same antenna built by VK4DDC
The 6el 7.3M long 50MHz LFA of OE4VIE
The 7.3M long 6el 50MHz LFA as built by UK8OM
EI2GLB's 6el 7.3m 6m LFA with 7el 4m version on top
'on 6m I have worked 5 new ones this year A92,A7,SU,ST & JY and usuals in Carib and some NA as well
On 4m I worked the First EI-OH on the band as also worked a load of OZ's, But I am QRT on 4m now until I fix my 847'
Trevor EI2GLB
Performance Standard Loop 16mm or 0.63 Inch Loop
Forward Gain: 12.32dBi at 50.150MHz 12.33dBi at 50.150MHz
Front to Back Ratio: 22.87dB at 50.150MHz 23.17dBi at 50.150MHz
Peak Gain: 12.38dBi 12.4dBi
Peak F/B: 25.46dB 25.46dB
Build Dimensions using 1/2 inch or 13mm elements
Element Spacing in metres Half element Length in metres
Reflector 0 1.488
DE1 .333 1.236
DE2 .889 1.236 (1.234 with 5/8 inch or 16mm loop)
D1 1.66 (1.58 with 5/8 inch or 16mm loop) 1.377
D2 3.386 1.34
D3 5.286 1.324
D4 7.243 1.281
Notes:
DE1 and DE2 are joined at the ends by either 3/8 inch or 10mm tube when 1/2 inch or 13mm DE1 and DE2 are used. these end sections should be 1/2 inch or 13mm when 5/8 inch or 16mm main loop sections are used. If in doubt, Email me!
Feed point is ALWAYS the centre of DE1
Build Dimensions using 12mm elements
Element Spacing in metres Half element Length in metres
Reflector 0 1.4865
DE1 .330 1.235 (Loop ends 10mm)
DE2 .884 1.235 (Loop Ends 10mm)
D1 1.653 1.378
D2 3.385 1.340
D3 5.320 1.320
D4 7.299 1.281
Notes:
DE1 and DE2 are joined at the ends by 10mm tube when 12mm DE1 and DE2 are used. If in doubt, Email me!
Feed point is ALWAYS the centre of DE1
Performance plot with 13mm or 1/2 inch elements
Plot with 16mm or 5/8 inch driven loop with all other elements 1/2 inch or 13mm ( see build info)
Antenna layout showing the feedpoint (red circle) at the back of the loop closest to the reflector
SWR with 1/2 inch elements
SWR with 13mm elements