Dragon Radar

Dragon Radar (ドラゴンレーダー), called Bleeper in the Ocean Group dub, is a tracking device that makes finding the Dragon Balls more efficient, compared to conventional methods.

Overview
The portative Dragon Radar was designed, and built by Bulma to help locate Dragon Balls. Although the Z Fighters' Dragon Radar was developed by Bulma, Bulma is not the one who developed the concept of a Dragon Radar, as Emperor Pilaf, as well as the Red Ribbon Army, possess Global Dragon Radars that are implied to have been invented before Goku and Bulma met each other. Dragon Balls emit a faint electromagnetic pulse, which Dragon Radars can detect. The Dragon Radar developed by Bulma points arrows in the directions of nearby Dragon Balls. Pressing the button on the top can cause the view to zoom out and show a more detailed map of the area.

Dragon Ball
The Dragon Radar is first shown in Dragon Ball right before Bulma meets Goku on Mount Paozu. She uses it during their first adventure to find the Dragon Balls, after which she gives the radar to Goku so that he can retrieve his grandfather's Four-Star Dragon Ball. After the 21st World Martial Arts Tournament, Goku accidentally breaks the Dragon Radar on the Muscle Tower, so he goes to West City in order to find Bulma and repair it. He breaks it again while fighting General Blue in Penguin Village. During his search for a capable mind to fix the radar, Goku meets Arale Norimaki from Dr. Slump, who asked her father/creator Senbei Norimaki to fix it, but Senbei could not make heads nor tails of it. Senbei's genius baby boy Turbo fixed the radar while nobody else was looking, but General Blue steals it, so Turbo builds a new one using material from Senbei's airplane.

Before the Fortuneteller Baba Saga, Emperor Pilaf creates a box that disrupts the electromagnetic pulse given off by the Dragon Balls, which obliged Goku to visit Fortuneteller Baba in order to find Pilaf's Dragon Ball and revive Bora.

Dragon Ball Z and Dragon Ball GT
The Radar is used frequently by Goku and his friends in Dragon Ball and Dragon Ball Z, but in Dragon Ball GT, the Dragon Radar is assimilated by the robot Giru, giving him the ability to find the Black Star Dragon Balls for Goku and the others.

Unfortunately, the usage of the Dragon Radar has severe consequences; due to the massive overuse of the Dragon Balls, the negative energy within them accumulated and resulted in the birth of the Shadow Dragons.

Other Radars
Bulma's Dragon Radar is not the only device capable of locating Dragon Balls. Throughout the series, many other devices that work much the same way are also seen. One often seen is a Global Dragon Radar.

Red Ribbon Army
During their hunt for the Dragon Balls, the Red Ribbon Army have their own version of the Dragon Radar, kept in the Red Ribbon Army Headquarters. Theirs is rather primitive and can only give a general idea of where the Dragon Balls are, rather than pinpoint their precise location. Large groups of soldiers have to be dispatched to the area involved, resulting in many man-hours of backbreaking labor and invading of innocents' homes.

Emperor Pilaf
Emperor Pilaf eventually built his own, superior Global Dragon Radar version. It is shaped like a globe in order to minimize map distortion. It is installed in his floating airship, and is able to show the Dragon Balls' exact location on the planet.

Other Z Fighter Radars
Along with radars invented by villains, the Z Fighters also had many different Dragon Radars. Although these radars did not differ in form or function from one another, they were still different items. In fact, the Radar used in the majority of Dragon Ball Z is actually not the one Bulma introduced in "The Secret of the Dragon Balls" (that one having been stolen by General Blue, and given to Colonel Violet and later to General Copper).
 * Turbo Norimaki created a new radar for Goku when the old one was stolen by General Blue.
 * Bulma created a new radar at Master Roshi's prompting during the King Piccolo Saga.
 * In the movies Dragon Ball Z: Fusion Reborn, Dragon Ball Z: Wrath of the Dragon, and the beginning of the Shadow Dragon Saga, the Z Fighters split up into seven groups, each tasked with finding one Dragon Ball. It is presumed that Bulma made Dragon Radars for each of them, otherwise, they would not be able to find the Dragon Balls so quickly.

Video game appearances

 * Dragon Ball: Shenron no Nazo
 * Famicom Jump: Hero Retsuden
 * Gokuden series
 * The Legacy of Goku series
 * Dragon Ball Z: Budokai
 * Dragon Ball Z: Budokai 2
 * Dragon Ball Z: Budokai 3
 * Dragon Ball Z: Sagas
 * Dragon Ball Z: Budokai Tenkaichi 2
 * Dragon Ball Z: Shin Budokai - Another Road
 * Dragon Ball Z: Infinite World
 * Dragon Ball: Origins
 * Dragon Ball: Revenge of King Piccolo
 * Dr. Slump: Arale-Chan
 * Dragon Ball: Origins 2
 * Dragon Ball Z: Ultimate Tenkaichi
 * Dragon Ball RPG: Shōnen-hen
 * Dragon Ball Z: Battle of Z (equipable item)

Trivia

 * In the Dragon Ball episode 84 entitled "Rivals and Arrivals", the monk running the registration for the World Martial Arts Tournament is looking at a clock that closely resembles the radar.
 * The Dragon Radar in the Live Action Korean film is an old handheld LCD game. Possibly a Nintendo Game and Watch.
 * In 15th episode of the French anime Dofus: The treasures of Kerub, the titular character briefly brings up a Dragon Radar that he has in his possession.
 * The iPhone/iPod Touch application named DRadar emulates the Dragon Radar.