ノイズが少ないと評判の LFA の考えで作られたクロス八木．使っているのが WSJT の作者である K1JT Joe．取付がリア・マウント．使っている場所がベランダ．432MHz用のアンテナはこれしかない気がしてきた．
Joe Taylor, K1JT commissions InnovAntennas and G0KSC to design new 432Mhz EME and Radio Astronomy array for W2PU & the Princeton University, New Jersey.
2 of 4 antennas installed so far with excellent results!
More details will be released soon on the X-pol LFA Yagis used at Princeton in a joint paper to be released by K1JT and G0KSC in 2014, Watch this space!!
W2PU, the radio astronomy site of the Princeton University, New Jersey USA and the home of Joe Taylor, K1JT (the developer behind weak signal programs such as WSJT, JT65, MAP 65 etc.). Joe asked me if it were possible to produce a crossed LFA Yagi for 432Mhz (Radio astronomy is normally carried out on 406Mhz but Joe chose 432Mhz in order that the array could be used for EME (Earth Moon Earth) communication too. I agrred to the task but only on the basis the final antennas would have no compromise electromagnetically as the importance of alignment and external influences (even the coax cable feeding the antenna is an issue on 432Mhz) help decide how well (or not) and array on this band will perform, especially when it is crossed.
While Joe and I will prepare a paper on the extent of the design and how it works so well, some give-aways can be seen in the aboved close-up shot of one of the 432Mhz X-pol LFAs. First is the fact the antennas are all rear mounted (30 elements, 2 x 15el), the square boom supporting the elements is fibreglass to avoid interaction and the drive loops are made from brass which once adjusted, has been solded. Even the coax cable (ultra-thin, low-loss) is soldered directly to the feed point to avoid dismilar metal issues.
Watch out for next year for our joint paper on this subject which will most likely appear first in DUBUS magazine. Keep tunes to these pages as new, latest design antennas will be appearing over the coming weeks, ready for your over-winter projects! These will include a Quad-style LFA-Q antenna for 50Mhx with 3 elements on a 1.9m long boom which produces over 9.1dBi, WOW !!
73 Justin G0KSC