5760 MHz ...
......was the first microwave band that I set out to "chase" echoes on. It took almost 2 years and a move of QTH in order for me to achieve echoes. The original system was an extension of my "hilltopping" 6cm equipment. I ran a transverter with homebrew amplifier chain utilising IMFET-3 FETs. The basic transverter produced 3-4 W and this was fed to a "dish- mounted" PA utilising 4 x 5964-8 FETs. This produced approximately 20 W and with cable losses I was achieving ~ 13W at the feed. This amplifier utilises the same type "WA5TNY" board that was used originally with IMFET 5964-3's : which was used for the very first QSO on 5760 EME.
The feed was a screw polariser and after extensive tuning produced less than 2dB difference through 360 degrees rotation on a dipole Rx antenna. With the initial setup and very careful optimisation, I was able to finally hear my own echoes for the very first time in a 250 Hz Bw. After retuning of the amplifier I was able to produce closer to 30 W out and this allowed ~ 20 W at the feed.
The first few stations I worked had bigger dishes which compensated for my smaller setup and QSOs were achieved. The smallest station I have been able to work was a one running 15 W into a 4.5m dish. We had a number of unsuccessful attempts whilst he was running linear polarisation, but after changing to CP we succeeded.
The help I received from the whole 6cm EME community was marvellous and without them I would not be having the fun I currently am with my EME activities.
In due course, I was lucky to come across a TWTA for 6cm thanks to a local ham. This unit produces > 100 W and after incorporating the necessary safety / switching features it is now setup in the station. Needless to say finding my own echoes is now 7-8dB easier! My SSB echoes are now QSA 5.
