144 MHz EME station and antenna
My current EME Station My EME station is pictured in figure 1. The SSPA
is connected to the antenna using 20 meters of Ecoflex 15
low-loss coax cable. The cable loss at 144
MHz is 0.75 dB and this equals 160 W when running 1 kW.
Remaining cables are standard coax cables. The 8-element yagi antenna is WY208 from Wimo. It is horizontally polarized
with 11 dBd gain. The dipole element is a special version
which can handle up to 1200 W. I am still aiming for 15
dBd antenna gain as recommended by DK3QN Klaus (visit
his EME page).
Fig. 1. My current EME Station.
You can view my rotor concept in figure 2 below. The antenna
is turned with a Yaesu G-600 rotor (6a),
and elevated with a Kenpro KR-550 (6b). Both rotors are controlled
by the ERC-3D rotor controller (4) which operates the control boxes (5a
and 5b) using relays. The controlling software is PSTRotator (2).
It has a separate window dedicated to Moon tracking (1). The
interface between the PC and the Rotor Controller is a
USB-to-serial cable (3).
Fig. 2. How the rotors are controlled.
Fig. 3. My current 144 MHz horizontal yagi antenna.
Earlier EME antennasSpring 2017
I used a 2 meter long ash tree cross-boom with 2 x 6
element yagis. This array was light and the wind
resistance was low. The two 6-element yagis were PA144-6-2 from the company Dual
(YU1CF). Each antenna has 9.2 dBd gain and a pair provides 12 dBd gain with vertical polarization. I heard
the Graves radar (143.050 MHz) and a few powerful EME stations using
these yagis. No QSO yet. I decided changing to horizontal
polarization in order to hear and
Page updated 18-July-2017 by Lars Petersen, OZ1BXM.