144
Mhz EME Array 4x12 elements
·
Array
composed by 4 x 12JXX2
antennas
·
Extimated
gain on free space 18.8 dbd (21.0 dbi)
·
Center
of the "H" placed at 7 meter above ground
·
Horizontal
spacing 3,60 meter
·
Vertical
spacing 3,30 meter
· Secondary lobe on E-Plane at -12 db
· Average front to back ratio 26 db
50 Mhz is definitely my favourite band, but 144 EME is quite easy and you can find many stations all around the World to run with.
So, I decided to set up a "small" system to start a serious activity both CW and digital.
I chose the 12jxx2 antenna, wich has a good gain and a short boom length: 12,65 dbd and 5,60 meter. The pattern is clean and the temperature pretty good, just considering the small boom length.
I stacked 4 of them at 3,60 meter horizontally and 3,30 meter vertically on a simple "H" made by 40 centimeter diameter pipe and I obtained a good diagram of irradiation and an acceptable gain of 18.8 dbd.
The center of the "H" is placed on a tower at only 7 meter above ground.
The array is connected with the TS-2000 by 18 meter "Ecoflex 15" 1/2" coaxial cable, with an extimated loss around 0,6db.
The system has been completed the 10th of July 2004 and the first JT65B EME QSO has been achieved the 14th of July with Joop PA0JMV (2x16 elements yagi), running only 100 watts at my side (ERP 6.500 watts).
Just after few days of activity I already easily completed as many qso's as I completed in two years on 50 Mhz EME!!
