Portal/Transmission Received

The newest achievement, added in March 1, 2010, requires the player to find radios within almost every level, and bring them to specific points. A radio will have a red light on the front if it hasn't been brought to the correct location, and green if it has. The light persists across saved games.

Radios, aside from their standard music, may also pick up Morse code signals, or sounds similar to those found on modems. To get full benefit out of them, you need to use sound recording software, or otherwise extract the audio files from the game.

Chamber	Radio
Chamber 00	Radio is in relaxation vault. Move it to the button room.
Chamber 01	Radio is on camera to the right of the entrance. Move it to the exit.
Chamber 02	Radio is on the wall containing the hole where the portal gun fires through the window. Bring it to where you collect the portal gun.
Chamber 03	Radio is on the camera near the exit. The best reception is at the ceiling, on the corner between the two gaps.
Chamber 04	Radio is released with the storage cube. Bring it to the entrance.
Chamber 05	Radio is behind the door opened by two buttons. Shoot a portal under it before stepping through the door, and drop it into the pit that contained one of the cubes.
Chamber 06	Radio is above the pellet launcher. Shoot a portal near the launcher and grab it through the portal. Bring it to the exit lift.
Chamber 07	Radio is under the stairs. Bring it to the exit.
Chamber 08	Radio is on the end of the moving platform. Bring it near the entrance sign.
Chamber 09	Radio is within the window between the two chambers.
Chamber 10	Radio is in the third section, on the left. To get it, proceed with the test until you are on the other side of the gap, then stand as close as you can to the radio and jump towards it while pressing  E  repeatedly. Bring it to the yellow portal.
Chamber 11	Radio is on the exit door. To reach it, shoot a portal near that exit door, and grab the radio by standing within the portal. Bring it to where you collect the yellow portal gun.
Chamber 12	Radio is opposite of the button, on floor three. To reach it, drop down from the fourth floor onto the panels. Bring it directly under the angled panel.
Chamber 13	Radio is on the right-hand side of the chamber. Reach it through one portal directly above it, and return it to the entrance. Note that you cannot get back to that area once you go through the door unless you leave a portal behind.
Chamber 14	Radio is in the main corridor, but on an un-portable wall. Use the staircase area to launch yourself to the radio and grab it. Bring it to the center platform near the pellet launcher.
Chamber 15	A radio is hidden up behind the extended panel you use to launch yourself through the field. A portal up high on the wall next to the panel is enough to reach it, though it can be tricky. Bring the radio back to the entrance.
	A second radio is in the final room, within the pellet receiver area. Press the two buttons, and place portals in a way that allows you to jump into the enclosed area. Bring the radio to the exit, after GLaDOS releases you from the receiver.
Chamber 16	Radio is on the pile of five crates, and needs to be brought next to the area behind the walls.
Chamber 17	Radio is under the lifts leading to the exit. Bring it to the incinerator.
Chamber 18	One radio is behind the hole, found after platform one. The signal point can be reached simply by an infinite loop between the "2" floor marker and the ceiling, but there's a more permanent platform nearby the ceiling that you can use to listen to the signal.
	A second radio is in the room with all the turrets on platforms. It is on top of the box which has the pellet receiver (behind a door). The signal is where the moving platform allows you to jump to (with a small button).
	A third radio is after the door that is opened with the cube. It is at the bottom of the drop to the left of the door. The signal is just before the exit.
Escape Part 1	The first radio is in the Giant Incinerator, on the left. Set a portal just above it, and use it to escape the Incinerator. Then create another portal, and go through half of it to catch the radio without being burned. You will get the signal in an office, soon after the two big fans.
Escape Part 2	Just after the load screen, you will find some stairs to the right. Under the stairs the way is blocked, but portal through the fence and crawl into the vent to a small area containing supplies and the radio. The signal is above the next horizontal pistons you see, in the corner across from the red symbol.
Escape Part 3	After being ambushed by three turrets, you will find the radio near the broken sentry. In the next room, after knocking down the turret, enter the alcove containing supplies.
Escape Part 4	When you enter the turret arena, the radio is in the lower section, on the opposite side of where you entered the arena. When you exit and reach the two turrets that are dropped from the ceiling, find the way up, but drop down and bring the radio near the green motors.