From Rob PE1ITR
The maxwell foundation has set up a 4m websdr receiver on University of Technology Eindhoven (JO21RK). Frequency range is about 70.150 to 70.250. The antenna is an 4 element yagi @ 65m agl direction south. The LX0FOUR beacon on 70.161 can be heard. This is a great tool to monitor Es propagation.
This is the link: http://lindsey.esrac.ele.tue.nl/
Select the 4m band in the window left just below the waterfall screen.
The freq readout has at the moment a +4,5 kHz offset but that will be corrected later.