The American Radio Relay League (ARRL) is the largest association of ham radio hobbyists in the United States. One of the membership benefits of being an ARRL member is access to the ARRL forums.
Internet Relay Chat (IRC) is text-based chat system for instant messaging. Many IRC servers exist but perhaps the best known is Libera Chat, founded in 2021 by former Freenode volunteers. For more information on how to participate in IRC channels (chat rooms), see Libra Chat's guide to the Basics of IRC.
Lemmy is a decentralized and federated discussion forum, somewhat akin to Reddit, built on top of the ActivityPub protocol. For more information on how to participate in Fediverse discussions, see https://fedi.tips/.
Mastodon is a decentralized and federated short message service, somewhat akin to Twitter, built on top of the ActivityPub protocol. For more information on how to participate in Fediverse discussions, see https://fedi.tips/.
Reddit is a centralized discussion forum that promotes itself as "the front page of the Internet."
Stack Exchange: Amateur Radio
Stack Exchange is a large Q&A community with a vibrant segment dedicated to Amateur Radio.
QRZ is a call sign lookup database which features profiles for ham radio license owners, a forum, and private messages.
Usenet is the oldest continuously operating digital social media network. After years of neglect, it is seeing a resurgence in popularity due to growing dissatisfaction with centralized social media platforms.
Usenet messages federate between NetNews servers in a manner akin to e-mail, in fact most e-mail clients support Usenet's NNTP protocol and can double as a NewsReader. The best known free Usenet provider is Eternal September. For more information on how to participate in Usenet discussions, see Getting Started with Usenet.
|aus.radio.amateur.digital||Digital techniques in Amateur Radio.|
|rec.radio.amateur.antenna||Antennas: theory, techniques and construction.|
|rec.radio.amateur.boatanchors||Vacuum tube-based amateur radio equipment.|
|rec.radio.amateur.digital.misc||Packet radio and other digital radio modes.|
|rec.radio.amateur.dx||Discussion, tips, notices and news for DXers.|
|rec.radio.amateur.equipment||All about production amateur radio hardware.|
|rec.radio.amateur.homebrew||Amateur radio construction and experimentation.|
|rec.radio.info||Informational postings related to radio. (Moderated).|
|rec.radio.amateur.misc||Amateur radio practices, contests, events, rules, etc.|
|rec.radio.amateur.moderated||Amateur radio practices, rules, etc. (Moderated).|
|rec.radio.amateur.policy||Radio use & regulation policy.|
|rec.radio.amateur.space||Amateur radio transmissions through space.|
|uk.radio.amateur||Amateur radio and related matters.|
|uk.radio.amateur.moderated||Amateur radio and related matters (Moderated).|
X (Twitter) is a centralized short message social media service.