Welcome to the many new users on K6TU.NET – thank you for registering.
No surprise with the Bouvet DXpedition in full swing, many of you are building your own predictions for Bouvet.
Perhaps the most common error in building a propagation prediction is the choice of Station Configuration for the transmit and receive sides of the link.
It’s perfectly understandable that one of these represents your own station and the other, that of the DXpedition.
Here is the issue…
The site in use on Bouvet for the DXpedition was mandated by the Norwegian Authorities. It is on the south east side of the island at a place called Cape Fie.
Operation is from a steep slope that rises over the beach at Cape Fie. The high terrain in the middle of the island lies in the short path directions to both Europe and North America.
The terrain blocks most low angle radiation from the antennas in use by the DXpedition.
The propagation maps shown on the 3Y0J web site were produced by the DXpedition leaders and include antenna models that consider the impact of terrain on radiated signals.
Attempting to generate your own predictions, in particular using some of the system provided Station Configurations on K6TU.NET will be overly optimistic and misleading because these models do NOT include terrain effects.
I just saw one OM use a receive configuration of ‘Serious DX’er’ for the Bouvet end of a prediction. This configuration includes a 3 element Yagi at 55 feet with ideal terrain for 20, 15 and 10m bands. Totally inappropriate for the challenges faced by Bouvet.
A propagation prediction is useful and accurate when the parameters selected, especially the station configurations, reflect the configurations in use. For anything else remember that garbage in means garbage out.