The description on the web site is interesting. They are not "pirate" beacons but are more sophisticated than the Russian military beacons:
"OK0EU is short-wave QRP beacon net set up by the OK QRP Club as a part of the Multi-point continuous Doppler sounding system of the Institute of Atmospheric Physics of the Academy of Sciences of the Czech Republic (IAP CAS). The system is working on frequencies 3.59, 4.65 and 7MHz and is a source of experimental data for basic research of atmospheric waves and other disturbances in the upper atmosphere and ionosphere. IAP is running similar net in other countries too (Slovakia, Belgium, France, Argentina, South Africa, Taiwan). See the IAP web page for more information HERE.
The output power 1 W and low elevated dipole antenna of each transmitter simulate average working conditions of the QRPP radio station. You can use the beacon for your RIG calibration, stability measurement, narrow band receiving experiments, actual conditions testing etc.
The frequency of each beacon is set precisely by DDS and derived from the high stability 20 MHz TCXO. On 3.5 and 4.6 MHz five and on 7 MHz three transmitters with 4 Hz separation are running for multipoint measurement. The call sign and status is sent 40 Hz up."
