EME ( Earth-Moon-Earth ) communication has always been considered a true edge of amateur radio. It is both technically and psychically challenging - EME'rs are being nicknamed 'lunatics' for a reason - yet it rewards with unique amount of joy and satisfaction.
Being licensed for some 40 ( SP4KM - father ) and over 20 ( SP4K - son ) and having our playground on the HF - digital modes, contesting and lowbands - we decided it is time for an ultimate hamradio challenge - to get to the Moon ( and back, if possible ). We aimed both at popular and fast-growing digital EME ( JT65B ) and classic CW via the Moon.
The original idea of our EME station was based on the consideration of assumed effectiveness vs local conditions at our EME QTH, which is located in a cottage overseeing the lake in Kaplityny, 10 kilometers east of the city of Olsztyn ( our hometown ). It is a great place for EME because it is really quiet there, however the space available for antennas is limited and there are quite high trees around as well.
1st Phase of EME system development
We decided to build 2 yagi system and after evaluation of the available options we went for M2 MXP28 X-polarity 5WL antennas, offering ca. 18 dBd gain, good G/T and pattern optimized for EME applications. The First EME QSO has been made with EA6VQ on 13.06.2010.
We were able to make over 400 EME QSOs with over 50 DXCCs utilizing this setup. It provided comfortable communications with 4 yagi ( or larger ) stations, however working smaller 2 yagi and single yagi setups was a struggle for most of the time. Also working DXpeditions, that rarely use anything larger than 2 short yagis and have huge pile-ups of EME big guns in limited windows of common Moon, proved to be an issue. Since one of our main goals is to work 2m DXCC via EME, we had to reconsider the setup.
2nd Phase of EME system development
Long story short - in the tight space available we managed to expand our setup in Kaplityny to 4 MXP28 X-pol yagis, making it now 21 dBd system. Major works on the tower, and especially on the sledge construction were necessary due to weight and wind load factors of expanded setup. The first EME QSO using 4 yagis has been made with JE1TNL on 11.07.2012.
Having learned a lot of practical lessons with our initial setup, we made a point to develop flexible EME environment, enabling us to fight effectively Farady rotation. On TX side it can be achieved by having TX CIR capability available together with standard H and V TX polarity options ( through manual switching ). On RX side the solution is wideband adaptive polarity receiver ( IQ+ by HB9DRI ) coupled with great MAP65 v.2 software by K1JT ( H/V RX and WSJT9 software still kept as a backup option ).
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