Spectrum Effect, RF interference mitigation company, adds Boulder Ventures General Partner Kishen Mangat to its board, expanding it to seven members; Mangat leads his firm’s enterprise 5G investment strategy, and was previously Cisco’s vice president-general manager, mobility ... Tempest, telecom network solutions provider, hires Greater Tech Holdings’ Joe Hart, also former AT&T, as CEO; outgoing Chief Operating Officer Dan Firestone moves to board adviser role, effective Dec. 31 ... Fiber solutions provider Accelecom taps former Evermore Consulting Group founder Van Macatee, also former TCI Cable and Sprint, as chief operations officer ... SightGain, cybersecurity risk management company, hires Jerry Hoff, former NTT and ex-Sony, as CEO; Christian Sorensen, SightGain’s founder and previous CEO, moves to chief risk officer ... Ad management firm Mediavine promotes Jamie Lieberman to chief legal officer.

Lawler Metzger, law firm specializing in wireline, wireless and satellite communications, announces it's shutting down with year-end retirements of partners Greg Lawler, Richard Metzger and Gina Keeney … Atlas Digital Group appoints Altice’s Chad Neuhaus as chief operating officer ... Pax8, cloud commerce marketplace, names Robb Reck, ex-Red Canary, chief trust and security officer … iHeartMedia announces realignment in its Markets Group, shifting division presidents: Bernie Weiss, Paul Corvino and Tom McConnell for Region Division; Kristin Foley, Chris Soechtig, DJ Hodge and Nick Gnau for Metro Division; and Shosh Abromovich and Dan Lankford, Community Division; also promotes Amy Leimbach to president-Austin, Dallas and San Antonio markets; and names Tony Coles president-multicultural business and development and he continues as president of BIN: Black Information Network.