Private station Radio Dechovka's website has this announcement (translated from Czech):
"Terrestrial broadcasting: We would like to warn the listeners that on February 28 all medium-wave transmitters on the frequency AM 1233 kHz will be switched off. "
"After February 28, 2021, lovers of medium waves can retune to the AM 792 kHz frequency, from the Hradec Králové - Stěžery transmitter. ... and soon at 1260kHz!"
(Radio Dechovka often plays brass band music - its logo includes a trumpet)
(Czech public broadcaster Cesky Rozhlas is scheduled to close down its MW and LW transmitters by December 31st 2021 - see Communication October 2020)
Thanks to Alan Pennington, BDXC news