this afternoon I got a new distance record with a 2,- EURO cheap antenna: 100 km from my home to DB0SUN near Hannover (Deister). Received with a quick-n-dirty wire groundplane calculated on this page:
http://www.changpuak.ch/electronics/lambda_4_gp.php
All wires are about(!) 162,5 mm long.
Not too bad for a simple wire GP, I think. :)