The ##rtlsdr IRC Freenode chat channel will be moving to irc.libera.chat. However ##rtlsdr admins note that the Freenode channel will remain open for now. This move is in wake of the recent takeover drama surrounding Freenode, and the resignation of the majority of Freenode staff.
The ##rtlsdr IRC channel is where many RTL-SDR, software defined radio and RF enthusiasts hang out. You can join and idle with any IRC client, or a web client is available at https://kiwiirc.com/nextclient/irc.libera.chat/##rtlsdr.
A discussion about the move has also been opened on Reddit /r/rtlsdr.
Many other related project channels such as #gnuradio are also moving over to Libera.