I've been adding webinars by PracticalShowTech, mostly they involve RF- mics, IEMs,
point to
point, intercom; COMS (in caps) of the matrix and wireless types, including CrewCom; RF over fiber (cool stuff).
The folks behind PST are
Mac Kerr (moderator of Live Audio Board), Pete Erskine of Best Audio (when all the other old
road dogs have gray hair, Pete went green!), Henry Cohen of Radio Aktiv Designs (wireless coms) and a rotating cast of Greek Chorus. Serious CVs....
All the webinars have been archived on either GoToWebinar or
Zoom (depending on original streaming). The archive
page is here:
practicalshowtechcom.squarespace.com
Free, but you have to sign up each time you view. The content is well worth the minor inconvenience. Take a look!