Monday, September 13, 2010

Results of my first MEPT experiment

From 10/9/2010 to 12/9/2010 my 30m MEPT was transmitting on 10140.030 KHz with FSKCW3 and only 160mW of power. From the first day of operation, I started to receive repeated reports through the QRSS Knights mailing list with positive comments. Based on my QRPp power I can say that the final results exceeded my expectations.

I received reports from 12 stations (G3VYZ, G4CDY, G6AVK, I2NDT, IZ1KXQ, ON5EX, ON5SL, PA0TAB, PA1GSJ, VK2DDI, VK6JY, ZL2IK) that are located on 6 DXCC countries (England, Italy, Belgium, Netherlands, Australia, New Zealand) and 2 continents (Europe, Oceania). Until now my longest DX is ZL2IK from New Zealand. The distance between us (from KM17uw to RF74ci) is 17376 km and this rises my personal QRPp record to 108600 Km Per Watt!

In order to have a better visual representation of my experiment results, I created the log as a KML file that is readable from Google Earth and Google Maps. In this way the reception reports log is more interactive. The color of each placemark defines the type of the station (MEPT or receiver). When the user clicks on a placemark the description of the reception report appears (date, time, location etc) including a small thumbnail of the received signal that is linked with the full size screenshot of the FFT software. The final result of the produced KML file is shown below:

View Larger Map

What comes next? First of all I will reprogram tomorrow the microcontroller to increase the dot length from 3 to 6 seconds (FSKCW6) and see how this will affect the quality of my signal as according to theory this change must improve my SNR to about 3 dBs. Also I will try to change my transmit frequency to a more clear spot within the 100Hz window because I noticed that around 10140.030 KHz there was a lot of activity in US and this made my signal undetectable from the US online grabbers (because of local QRM). Stay tuned!

[1] QRSS Knights, Mailing List,
[2] Google, Google Maps,
[3] Google, Google Earth,

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