WSPR distances

LB9YE and I have exchanged WSPR spots several times today. When he spots me the distance is 1489km. When I spot him it is 1533km. I assume it is to do with where in the QTH square the measurement is taken from.

Full QTH locator

QTH locator (10m digit version)

Most times people exchange QTH locators as a 6 letter/number combination but for even greater accuracy, more can be added to give a better fix. My full QTH locator is JO02DG95LK. Note the 95LK on the end of JO02DG.

As an example, on the 25km path to G0LRD the error using 6 digits is around 1km. The actual path (using the full 10 digit locators at each end) is 26.516km. Sometimes the error is such that paths appear longer with 6 digits. It all depends on where in the 6 digit square one sits.

Very accurate QTH locator data

Today I found that my very accurate full QTH locator is JO02DG85VD by looking at http://no.nonsense.ee/qthmap/?qth, zooming in and reading out the 10 digit alphanumeric code. You may want to try and find yours too if you want to know distances from another station very accurately.

Full QTH locator square? Find it here

Just discovered that my full QTH locator is JO02DG85VD . This was found using a website I'd not come across before http://no.nonsense.ee/qthmap/ .