Angel Radio

A short wave radio in Heaven, tuned to all angels in existence.

"Angel Radio" is Dean's nickname for the method of mental telepathy angels use predominantly to communicate with each other over long-distance.

The phenomenon is first nicknamed by Dean in 4.09 I Know What You Did Last Summer, but his nickname catches on among angels and demons and eventually gets used on a regular basis by Castiel, Metatron, and various angels and demons when describing the phenomenon. Through a process of blocking out certain subsonic frequencies, an angel can effectively remove the direct link they have to Heaven, essentially "turning off" angel radio. However, even if an angel loses their grace, they can still overhear angel radio like Anna Milton and Castiel.

Any conversations made through angel radio can be overheard by other angels or radio-like devices built to pick up their frequencies, however certain classes of angels like cherubs and grigori have their own separate frequencies on angel radio to communicate with each other in private.

Episodes

4.09 I Know What You Did Last Summer

Sam and Dean find Anna Milton, who has escaped from a psychiatric hospital. She describes how she can hear the angels talking. Dean responds: "So, they lock you up with a case of the crazies when really you were just... tuning in to angel radio?"

4.10 Heaven and Hell

Sam: "It seems like they want her bad, and not just 'cause of the angel radio thing."

Dean: "So, Anna, what's playin' on angel radio?"

Ash's "holy-rolling police scanner."

5.16 Dark Side of the Moon

When Sam and Dean are in Heaven, Ash describes how he has rigged up a laptop to overhear and translate the angel's speaking in Enochian - what he calls a "holy-rolling police scanner."

8.10 Torn and Frayed

Samandriel uses telekinesis to remove the spike preventing him from using angel radio. He gets a message to Naomi, but Viggo walks into the room and discovers that he's been on angel radio. Although Samandriel denies it, Viggo doesn't believe him and reinserts the spike into his forehead. Later, Viggo uses a headgear torture device to affix the spikes to his head and prevent him from removing them again.

8.23 Sacrifice

Metatron listens in on angel radio to find a "cupid" so that he can retrieve their bow to seal the gates of Heaven. He calls it the "Cupid Frequency."

9.01 I Think I'm Gonna Like It Here

Castiel, like Anna, can hear the angels even though he has lost his grace and is human.

9.23 Do You Believe in Miracles?

Metatron sets up a radio in his office to broadcast to all angels on Earth and in Heaven across all frequencies of angel radio to let them know he is traveling to Earth and closing the portal while he is gone. When confronting Castiel in his office, he doesn't realize Castiel has activated the microphone and Metatron's true intentions and opinions of the angels are broadcast to everyone, leading to his downfall.

12.08 LOTUS

Castiel is besieged by voices on angel radio. He tells Sam and Dean that there has been a massive surge in celestial energy, which can only mean that Lucifer has sired a Nephilim.

12.10 Lily Sunder Has Some Regrets

When Lily Sunder confronts the angel Benjamin in a fight, before she delivers a killing blow, Lily allows Benjamin to send out a message over angel radio, which is received by the angels Mirabel, Ishim, and Castiel. Through her century-long honing of Enochian magic, Lily Sunder is also able to tap into angel radio and listen in to what the angels are saying.

12.19 The Future

At a pit stop, Castiel tells Kelly Kline that he has been communicating with Joshua regarding what to do next with her.

13.01 Lost and Found

The Nephilim, Jack, is shown to be able to hear angel radio, which causes him great pain.

13.09 The Bad Place

Jack learns through angel radio that angels have captured Kaia Nieves. During the angel siege, Dean asks if Jack can do anything to help; Jack tells him he could try but the angels would just hit him with angel radio.

13.13 Devil's Bargain

Castiel learns from angel radio that a vessel has been found mutilated -- a cherub whom Lucifer had murdered after stealing his grace. Later Sister Jo reveals to Lucifer that she heard of the cherub's death on angel radio.

13.23 Let the Good Times Roll

After Lucifer's surprise arrival back in their universe, Castiel checks angel radio in hopes of tracking him. However, Castiel finds that he can hear nothing but static, a fact he finds disturbing.

14.08 Byzantium

After the Cosmic Entity lays siege to Heaven in search of Jack, Castiel reports to Sam and Dean that angel radio has sent out a distress signal and all the gates to Heaven have been opened, including the gates sealed by Metatron.

14.18 Absence

Castiel arrives at the playground to find out if Mary Winchester is in Heaven. Using angel radio to try and get Naomi's attention, he is instead met by Dumah, who confirms Mary's death.

15.07 Last Call

Castiel states that angel radio has been silent for months.

15.11 The Gamblers

The Grigori Kabaiel reveals to a resurrected Jack that his kind have their own frequency on angel radio. His brother Sariel called out to him on it before Jack killed him, which he realizes Jack did on purpose so he could draw the fallen angel out.