Sunday, January 3, 2010

Perseus Markers - just another try


During the Christmas period one of the favourite short wave DXing targets has always been the Papua-New Guinean stations. These are few still left on 90 mb. As I had no possibility to check them during their Christmas programs or the often longer New Year´s Evening shows I made a short preview recording a Perseus file 3200-3400 kHz on Dec 29th while visiting my DX-ing cottage.

Quite a few fellow DXers have been making graphs using the Markers Log - feature of the latest Perseus software (2.1h). One major problem to do the graphs is the file format - it does not write the markers loggings as a tabulated file but rather a vertical file one freyency after another (figure showing the format). I transferred all the rows to Excel, made a "manual transpose" of the three channels info into a horizontal table, made then a new file with only the right rows (every 3rd) and got finally a table where you can make a graph. It is a bit hard to explain but everyone knowing how to operate with Excel can do that. Maybe there are easier ways and easier softwares (I do not know how e.g. SciDavis can do that), but when you know how to do it it is rather easy with Excel as well.

The signal of 3365 Papuan was the strongest starting from about -85 dBm. The noise level using the BOG under 20 cm snow was rather low around -140...-150 dBm. The signals of 3260 and 3325 were a bit weaker. Note that although the graph shows 3260 going stronger that is not true: an utility station started after 2030 utc and occupied the channel. So using large spans with known signals could lead wrong information!
Finally you can listen to an example of PNG Madang 3260 recorded earlier this december (Dec 2nd)- the signal was quite strong during the sign on around 19utc! video

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