Updated on 09-12-14
In July 2009 I started building my 6 cm EME station.
The first thing I needed was power output. For this I had a TWT amplifier which had a defect in its power supply. I started to investigate the reason for this and found several components which where defect. After replacement it started up but gave far to high filament voltage on the TWT, so I had to switch it off. Further investigation gave me some more defects and after replacement of these the amplifier started up and after 2 minutes delay it even gave ready. I waited for a few minutes and than switched the TWT to operate and helix current looked normal. I had to connect dummy loads and a signal source to measure if it was bringing output. After some corrections to the measured results I found the TWT amplifier worked fine. I measured 56 Watt output on 5760 MHz which is very good. The amplifier was specified to deliver at least 40 Watt so I was quite happy with this result.
The next thing was to build a feed for my dish. I googled internet and found the septum feeds and also a feed from OH2AUE and decided to build them both. I went to our local plumber which had copper pipe of 42 mm and 35 mm available. The 35 mm was needed for the septum feed and the 52 mm was needed for the OH2AUE design.
I build both feeds but found problems with the septum feed giving bad return loss, only -10 dB, and even worse it did not bring me the expected circular performance. I expect I must have done something wrong with the septum. I will give it a next try but for the short time I will give my time to try to be QRV and give it a go with the OH2AUE feed.
The receiver and transmitter are also ready and now its
time to get it mounted into the dish.
It worked fine, I made 9 QSO's in this weekend. During the third QSO I blew my pre amp and had to replace the first fet giving me a bit lower performance. It was still good enough to hear my own echo's and work several more stations.
I still have problems with my pre-amp, during the activity
of 30 may 2011 I again blew my pre amp and replaced it with the less performing
pre amp with 1.2 dB NF.
Stations worked so far: