Graham, G8HVY has built and installed the two 7 element 4m LFA's I designed for him earlier this year and boy, do they look great!! The well-built duo produce in excess of 16dBi when stacked in this formation so without doubt, Graham will be heard well this year!
The 2 7el 4m LFAs installed at G8HVY
Graham's 2 LFA's can be seen above, with his 6el 6M Yagi in the middle. Due to the wideband characteristics of the LFAs, no antenna de-tuning occurs as a result of the 6M antenna being between the LFAs.
Graham reports the LFA's as having a Flat SWR across the whole 4M band. An indication of just how good the these 2 antennas are from an SWR perspective can be seen in the analyser shot below.
The analyser at G8HVY shows all, a perfect match, minimum reflected power.
Many G0KSC projects are now underway so more photos will be published very soon! However, do keep in mind there are many factors to take into account when building an antenna and if you are building for the first time, contact me and let me guide you. Graham uses insulators which electrically connect the elements to the boom and as a result an Insulator Correction (IC) had to be applied. This means the elements needed to be larger than those published. If a builder used the published sizes with these insulators, the antenna would not sit perfectly within the 4M band. Do contact me for help, I am happy to give it anytime.
If you wish to build one, two or more of these 7LFA4HVYs the details and dimensions maybe found here: http://www.g0ksc.co.uk/7el-low-noise-lfa.html
Look out for Graham this summer, I am sure he will be top of many pile-ups on 4m!
73, Justin