Hi all,

Good activity on 5,7 GHz EME was expected during the second week-end of july, thanks to the coordination of G3LTF.

I decided to have a try, using my 2,3 m offset dish and the system used normally for tropo and rain scatter.
This system consists of a transverter kit from DB6NT and a modified surplus 6 GHz amplifier, giving about 8 W output.
Noise figure of the system is around 1 dB.

The 5,7 GHz transverter has an output on 144 MHz and is followed by another transverter 144 to 28 MHz.
There are various 28 MHz outputs. One output goes to a yaesu FT840 HF transceiver.
Another output goes to an SDR, and another one to a calibrated 28 MHz receiver, allowing precise measure of sun noise and moon noise.
During operation, permanent reading of moon noise allows perfect aiming of the dish and confirms that the system is working alright.

Most EME stations use circular polarization, so a "septum feed" was built following a description by OK1DFC.
Dimensions were adapted in order to illuminate correctly the offset dish.

After optimizing carefully the position of the feed, I could measure 0,5 to 0,6 dB of moon noise versus cold sky. Sun noise was a good 10,5 dB, meaning that the receiving side was working correctly. The feed has some sidelobes and is far from perfect, but efficiency seems to be quite good.

Now the results: during the week-end, 13 stations from Europe, USA and Japan were heard.
To my great surprise, some of them were even able to decode my QRP signal and 3 good QSOs resulted !!!

Conclusion: this band offers very interesting possibilities for the experimenter.
Tropospheric propagation and rain-scatter allow surprisingly good distances even with very small set-ups.
The above results also shows that EME contacts are possible with very low power, thanks to the amazing receiving capability of some stations.

73
Eric
ON5TA