144 MHz EME station and antenna

EME Equipment

Yaesu FT-847sspa forfra
8 element yagi
Yaesu FT-8471 kW SSPA8 element yagi and 2 rotors.Sequencer

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).

EME  lay-out  single yagi
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).

2 rotators
Fig. 2. How the rotors are controlled.

Fig. 3. My current 144 MHz horizontal yagi antenna.

Earlier EME antennas

Spring 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 work stations!   

Page updated 18-July-2017 by Lars Petersen, OZ1BXM.