Československý Rozhlas (or Czechoslovak Radio in English) began regular broadcasts on 18 May 1923. It retained this name until 31 December 1992 when the country was split into the Czech Republic and the Slovak Republic. Each country then had their own broadcast organizations.
Československý Rozhlas was audible at our home in southern Germany on a number of frequencies on medium wave. Some were easier catches than others. I sent reports to their headquarters in Prague and received the regular Radio Praha (Prague) QSL cards in return. The personnel got the frequency correct on only one of the cards (1098 kHz.) I assume that it was because they normally did not handle reception reports for non-shortwave transmissions. I have noticed this type of thing from other broadcasters. I photo-shopped the correct frequencies on the QSL copies below.