A Low-Noise 'Urban' 14 element ultra low-noise LFA Yagi for 144MHzRevised 27th August 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. If you suffer with noise from living in the city, or want the perfect quite EME array, this is another low-noise antenna from G0KSC This antenna has been built and tested with a version of this one being marketed by Vine Antennas. Again, like the other 2M LFAs before it, this antenna has better allround performance than any other antenna of the same boom length, included within the VE7BQH G/T table. This antenna is particularly good for EME purposes due to the class leading low noise (Sky Temperature) and G/T figures mentioned above. See the bottom of this page for more information. 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 nec versions with EZNEC versions. Unless you have EZNEC pro/4 you are using nec2 NOT nec4
- 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
Download the European and UK/USA versions of this antenna in EZNEC format HERE
An 11 Element 144MHz LFA on test In order to show how clean the pattern is on this antenna, I have presented below first the Elevation plot then the Azimuth plot from 4NEC2 modelling program. These plots show much more clearly then EZNEC. 
The 14el Elevation plot presented in the 4nec2 antenna modelling package. At first glance, the pattern does not look balanced. That is until you start to realise how much rearward suppresion is going on here. 
The all important 'Super Clean' Azimuth pattern as presented within 4nec2 Download the European and UK/USA versions of this antenna in EZNEC format HERE
Note: Performance figures given at 144.100MHz, the EME centre frequency Performance European Version UK/USA Version Forward Gain: 16.54dBi at 144.100MHz 16.54dBi at 144.100MHz Front to Back Ratio: 42.96dB at 144.100MHz 40.33dBi at 144.100MHz Peak Gain: 16.54dBi 16.54dBi Peak F/B: 46.38dB 43.2dB Bandwidth: 1.5MHz below 1.1:1 1.3MHZ below 1.1:1 Build Dimensions for European Version - If you need 12mm Loop sizing mail me Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .5075 10mm Diameter tube or solid rod DE1 .261 .447 13mm Tube DE2 .428 .447 13mm Tube D1 .611 .479 10mm Diameter tube or solid rod D2 1.062 .4615 10mm Diameter tube or solid rod D3 1.545 .457 10mm Diameter tube or solid rod D4 2.15 .451 10mm Diameter tube or solid rod D5 2.849 .4455 10mm Diameter tube or solid rod D6 3.624 .4405 10mm Diameter tube or solid rod D7 4.464 .4365 10mm Diameter tube or solid rod D8 5.338 .4305 10mm Diameter tube or solid rod D9 6.213 .426 10mm Diameter tube or solid rod D10 7.125 .42 10mm Diameter tube or solid rod D11 7.984 .42 10mm Diameter tube or solid rod D12 8.817 .4035 10mm Diameter tubeor solid rod Notes: DE1 and DE2 are joined at the ends by either 10mm tube Feed point is the centre of DE2 Please read the 'how to make the LFA Loop' page here Download the European and UK/USA versions of this antenna in EZNEC format HERE 
SWR Plot for the European version of the G0KSC 14el 144MHz LFA Yagi Build Dimensions for UK/USA Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .5085 3/8 inch Diameter tube or solid rod DE1 .261 .447 1/2 inch Tube DE2 .428 .447 1/2 inch Tube D1 .613 .4795 3/8 inch Diameter tube or solid rod D2 1.062 .4625 3/8 inch Diameter tube or solid rod D3 1.545 .458 3/8 inch Diameter tube or solid rod D4 2.15 .452 3/8 inch Diameter tube or solid rod D5 2.849 .4465 3/8 inch Diameter tube or solid rod D6 3.624 .4415 3/8 inch Diameter tube or solid rod D7 4.464 .4375 3/8 inch Diameter tube or solid rod D8 5.338 .4315 3/8 inch Diameter tube or solid rod D9 6.213 .427 3/8 inch Diameter tube or solid rod D10 7.125 .421 3/8 inch Diameter tube or solid rod D11 7.984 .421 3/8 inch Diameter tube or solid rod D12 8.817 .4045 3/8 inch Diameter tube or solid rod Notes: DE1 and DE2 are joined at the ends by either 3/8 tube Feed point is the centre of DE2 Please read the 'how to make the LFA Loop' page here Download the European and UK/USA versions of this antenna in EZNEC format HERE 
SWR Plot for the UK/USA version of the G0KSC 14el 144MHz LFA Yagi 
Antenna Elevation Plot 
European version Azimuth Plot 
UK/USA Elevation Plot EME Notes This antenna makes an excellent EME antenna when configured in a 4 bay stack. Below is the TanT output screen showing that sky temperature is 217.7 Kelvin for this array which is excellent. Not only this, G/T which is the figure of merit used to determine an antennas ability to receive signals is better than any other antenna of this length (-0.96dB). This is the shortest ever arrya to go below -1.0 G/T for this length ans the 4 bay spacing is not optimised yet! 
G/T and Sky Temperature are better than any other antenna of this boom length, period. 
4 x 14 element LFA Yagis configured in a 4 Bay array 4 metres Vertically and 4 metres horizontally. With more time, even better results can be achieved.
Download the European and UK/USA versions of this antenna in EZNEC format HEREAs always, any questions please ask! Justin G0KSC
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14el 144MHz LN LFA
