I am almost done with the Transmission Received achievement in Portal 1. The only radio I'm missing is the second one in chamber 15. It's not where it is supposed to be.
Portal - Transmission Received Achievement Guide
YARN | Transmission received. | Rogue One: A Star Wars Story (2016) | Video clips by quotes | 42d4b3a2 | 紗
Steam Community :: Guide :: Transmission Received: finding missed radios
Portal - Transmission Received Radio 17 (PC) ◁1440P/60▷ - YouTube
Uncovering the truth message by message - Generation Zero Forum
Share Project Transmission received | MEGA™ Unboxed
Geeky Clues Suggest Portal Sequel Is Coming | WIRED
Portal 1: all radios and signals for the "Transmission Received" achievement - YouTube