Tutorial - Finding A QSO Window

Finding A QSO “Window” --

This is a procedure developed by Cesar, PY2YP, using VOACAP and an Excel(TM) spreadsheet. It looks very interesting and useful. I hope Cesar doesn’t mind me sharing his idea in this way.

Please do not hesitate to post comments and suggestions about the procedure. I could have easily overlooked something while creating my portion of this document.

Cesar explains –

From time to time, when I need a rare country, say the Andaman Is, which was my last needed country, or KH8/S. I try to find a QSO window in order to maximize my odds to log the country.

I define “QSO window” as being a time span when the signals from the major areas are weaker then mine or at least equal to mine.

To do that, first of all, I select the major interfering areas, these are: K6 (Los Angeles), K2 (New York), JA (Tokyo) and I0 (Rome). These areas roughly represent the biggest pile-up generators.

After that I define the antennas and power for those areas, which are better or at least equal to mine.

Then I run those circuits, with the needed DX as target.

Here the work really begins. I need to work out the reports into an Excel(TM) spreadsheet and then produce the needed graphic.

Our reply – This is a very interesting and worthwhile procedure. Perhaps I can suggest a way to achieve similar results and let WinCAP Wizard do most of the work.

With WinCAP Wizard, the basic input configuration would be to a make the DX target the default “station”, or transmit station, and do predictions from there to a custom “prediction batch”. One of the default “contest plan” prediction batch tables seems like a good start for use as the “interfering” stations. For the prediction results display, the “Comparison Chart” should do nicely. Once you set up and configure your custom "prediction batch" you can use it again and again for new targets - you will only need to set the new DX target as the default “station”.

Here are some step-by step instructions to help get started:

1. Make the desired DX target the default location. Open the “DX Gazetteer” and find the desired target. There are several ways to quickly locate the Andaman Is and see the prefix is VU4; hint use "incremental searching in the "country" column. After selecting the VU4 target, click the button labeled “New Station”. This step made the VU4 the default-transmit station, or "station". Note - all the DX Gazetteer azimuths and distances are now “from” the Andaman Is location. This step simply ”added” another “station group”. It’s very easy to change back to your own, or any other, custom "station group". You can configure many, many “station groups”. See the Station-Parameters Manager.
2. Check the default circuit parameters that will be used for the batch of circuits. Open the “Circuit-Configuration Manager”. Check the “Frequencies” tab/page; I’ll use the “contest bands”, but all bands would surely be better for this exercise. Only the Station, Month and Frequencies tabs are relevant for Prediction Batch predictions. Information from the other tabs is specified individually for each circuit in a “prediction batch” group.
3. Select the desired “group of interfering locations”. Open the “Prediction-Batch Manager ”; from the Analyze or Menu button. Click the button labeled “Switch” and select one of the two default “Contest-Plan” tables. Double click the table name or select it and click the Open/Create button. I recommend “not” modify the default “Contest-Plan” tables randomly, but if necessary create new tables and customize those. For this particular exercise we would really want to create a custom table. The South American location in the default Contest-Plan tables is Paraguay. Paraguay was chosen for the South American location in our default tables because it’s near the middle of the continent. For better results PY2YP would surely want to use his own location in place of Paraguay. For detailed information creating your own custom prediction batch, see the “Tutorial - Prediction Batch” topic.
4. Create the "prediction set". In the “Prediction-Batch Manager”, click the Analyze button. When the prediction batch prediction set is done, depending on your configuration, you may be presented with various charts and reports. The results that are automatically displayed for predictions are selectable from the Master-Control Palette “Results” button and the Default Prediction Views item. We are currently only interested in the “Comparison Chart” so close any other result views.
5. View the “Comparison Chart”. On the Master-Control Palette, click the Chart button, move down to “Prediction Batch” and click “Comparison Chart”.
6. What a mess. At first glance, the “Comparison Chart” probably looks like a mess. Lets simplify it somewhat. Start by insuring we are looking at SNR and either CW or SSB. Then, on the left side of the chart are 14 checkboxes and continent identifiers – each represents a prediction result from a circuit in our prediction batch. Since we used the “Contest-Plan” table, the first 7 circuits are “short-great-circle paths” and the last 7 circuits “long-great-circle paths”. Un-check the last 7 circuits to hide the “long-great-circle paths”. This may make a small improvement in the chart readability.
7. You will want to experiment a bit hiding and showing various circuits on the chart. This helps identify which line is which on the chart. Further, you may want to check for a usable “SA” long-great-circle circuit.
8. My predictions for this exercise are for September 2006 using default antennas and “big-gun” receive station settings. The most useful chart parameters are probably SNR, Rel (reliability) and MUFDay. It appears that “if” 10M “opens” we should easily be “heard” on CW by the VU4 between 1500Z and 1600Z. However, looking at the “MUFDay” (MDay button), there is only a 33% chance 10M will open at 1500Z and 26% for 1600Z. For 1500Z that 33% should work out to about 1/3 of the days during the month. Recall that MUFDay is the fraction of the days of the month that the operating frequency will be below the mode MUF. In other words it is the fraction of days one can expect normal ionospheric reflection for the indicated most reliable mode at that frequency. Unfortunately we do not know which days during the month. The 10M band could be open several days in a row and also closed for several days consecutively. It does seem worth a listen. Otherwise, 1700Z on 15M should be a good circuit and Africa is most likely to be our main competition.
9. You may also find it useful to look at the Contest-Plan SmartChart. This chart may confuse matters a bit, as it seems to suggest different “best hours”. The reason is the chart is based more on “probability”. In any case this view seems to be worth a look.