LF: Doppler shift

["Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>]

Hello group,

The question is a bit off topic, so longwave-only readers can push the 
delete button now.
A friend of mine is interested in QRSS tests on 10.1MHz (30 meter) and one 
of the things we are discussing is the longest useable dotlength is on that 
frequency. Apart from TX (and RX) stabilty doppler shift due to ionospheric 
refections will cause frequency instability.
Does anyone have an idea how much Hz the doppler shift can be on 10MHz ?
Is there any info available on the web ?

73, Rik  ON7YD