DM7A - March 2018 Results and Pictures

Some interesting tests this time. We used a ADS-B receiver (RTL dongle with SAW filtered LNA) to receive some planes direct way. The distances were up to 500km (PA border, north sea) which was very nice. Antenna was a GSM Logper antenna, which seem to work quite well at 1090MHz.

On 70cm we used a CW Skimmer Server from a Redpitaya to fill the bandmap of VUSC. On 70cm were all the SSB and CW signals are mixed in the band the results are not that good. Most likely in “CW only” subbands the decoder is more effective. VUSC inclusive transceiver control worked like a charm. Some of the spots can be seen here

The results were mixed on 70cm because we lost some time in the beginning through some massive QRM from our own 2m station. Normally we have no problems although antennas are quite close, but thanks to good input filtering of the 70cm LNA we never had these problems in the past. It could be solved by disconnecting the connectors from the amplifier cleaning them and connect them again. Obviously there was some broadband corona effect caused by some metal whiskers inside.

Late start on 2m caused by some solder action of an open PTT wire in the transverter and a faulty analog instrument in our working horse tubed power amplifier. Than we catched up the race with 85QSO/hour which is quite good for march and is a sign of good activity. The teamwork with DG0LFF, DL6DVU and DH1FM was good so we could compensate a little bit the lost of points due rotating problems of both antenna systems and the problems at start
-2MRE