Thank you very much, now I understand it. I plotted Doppler shifts calculated from your formula and I got exactly same graphs as showed on that webpage.
I am starting to understand the problem... Orbital velocity is calculated fot Earths centre and receiver is 6378 km from that centre, right? But I still don't see the way to calculation you posted...
For any frequency in Table 1 I got same relative velocity -6718 m/s caluclated this way:
v = - \frac{\Delta f c}{f_0}
For orbital speed:
v = \sqrt{ \frac{G M}{ R + h }}
at altitude of 800 km i got 7466 m/s. Difference is 748 m/s. That means, I didn't get twice the shift, from shift...
At page http://www.qsl.net/vk3jed/doppler.html" is discussed Doppler shift at various ham radio frequencies. I calculated for this Doppler shift relative velocity of their satellite as 6720 m/s. Their satellite in height of 800 km above ground and at circular orbit should have velocity of 7453...