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