A Low-Noise 'Urban' 16 element Plus2 LFA Yagi for 144MHz Revised 3rd December 2009 V1.0 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. The new LFA Plus2 range includes an addtional 2 reflectors which are used in order to maintain pattern stability throughout the 1MHz coverage (144-145MHz). This is the ultimate in 2m VHF performance today, the new LFA Plus2 is the one to beat showing flat SWR, pattern stability throughout and better sky tepmerature and G/T figures than any other Yagi of the same boom length (VE7BQH list).
Currently these antennas are available in METRIC SIZES ONLY. Imperial will be launched at a later date. As with ALL LFAs this antenna requires no matching, it has a 50 Ohm input impedance. Download both the European and UK/USA EZNEC files HERE 
The look fo the 16el Plus2 when built 
4nec2 (with nec4 engine) Elevation plot of the 16el Plus2 LFA Yagi
The 16el Plus2 Azimuth plot from the 4nec2 antenna modelling package 
SWR as presented in the 4nec2 antenna modelling package using nec4.1 Double Precision calculation engine PLEASE NOTE: - This antenna WILL NOT show the true SWR in any antenna modelling package unless you are using one which uses the latest NEC4 calculation engine DO NOT confuse EZNEC with the NEC engine. EZNEC uses nec2 by default
- There are two sets of measurements listed below. One uses imperial sizes, the other uses metirc sizes. Ensure you use the correct one for the material you have
- 'within one or two millimetres' Will not do! take the time to ensure you get the spacing ant element lengths as close as you possibly can to the measurements below to ensure good, solid performance
- Please read the 'how to make the LFA Loop' page here
- Please do not alter segmentation or try to 'tune' the antenna unless you have nec4 or better. SWR will not read true within anything else
Download both the European EZNEC files HEREPerformance European Version Forward Gain: 17.26dBi at 144.300MHz Front to Back Ratio: 35.62dB at 144.300MHz Peak Gain: 17.27dBi Peak F/B: 35.69dB Bandwidth: 144-145MHz below 1.1:1 Build Dimensions for European Version - mail me if you need 13mm tube driven loop sizing
Element Spacing in metres Half element Length in metres Element Notes Plus2 Rear Reflectors -.086 .513 above and below loop by 300mm Reflector 0 .515 8mm Diameter tube or solid rod DE1 .144 .449 10mm Tube DE2 .310 .449 10mm Tube D1 .504 .481 8mm Diameter tube or solid rod D2 1.008 .464 8mm Diameter tube or solid rod D3 1.455 .4515 8mm Diameter tube or solid rod D4 1.952 .450 8mm Diameter tube or solid rod D5 2.664 .4485 8mm Diameter tube or solid rod D6 3.474 .443 8mm Diameter tube or solid rod D7 4.334 .439 8mm Diameter tube or solid rod D8 5.22 .435 8mm Diameter tube or solid rod D9 6.124 .431 8mm Diameter tube or solid rod D10 7.04 .4265 8mm Diameter tube or solid rod D11 7.985 .420 8mm Diameter tube or solid rod D12 8.904 .4145 8mm Diameter tube or solid rod D13 9.845 .4105 8mm Diameter tube or solid rod D14 10.687 .4085 8mm Diameter tube or solid rod Notes: DE1 and DE2 are joined at the ends by 8mm tube Feed point is the centre of DE2 Please read the 'how to make the LFA Loop' page here Download both the European EZNEC files HERE As always, any questions please ask! Justin G0KSC
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16el Plus2 144MHz
