As wspr activity has incresed by 100 % there are now 4 stations active on wspr...!
a quick re-org has adopted 502.4 KHz usb dial at the center of activity
giving 503.9 KHz =/- 100 Hz ie the very top area of the band.
Details are listed :-
http://groups.google.com/group/uk500khz/web/wspr-activity-from-the-uk
The frequency is now in use and looks to be effective
Graham
G0NBD
IO83LK