Search results
Results from the WOW.Com Content Network
Crystal radio used as a backup receiver on a World War II Liberty ship. While it never regained the popularity and general use that it enjoyed at its beginnings, the crystal radio circuit is still used. The Boy Scouts have kept the construction of a radio set in their program since the 1920s. A large number of prefabricated novelty items and ...
Crystal radios had no amplifying components to increase the loudness of the radio signal; the sound power produced by the earphone came solely from the radio waves of the radio station being received, intercepted by the antenna. Therefore, the sensitivity of the detector was a major factor determining the sensitivity and reception range of the ...
The foxhole radio, like a mineral crystal radio receiver, had no power source and ran off the power received from the radio station. They were named, likely by the press, for the foxhole, a defensive fighting position used during the war. There are also accounts of prisoners of war in World War II and in the Vietnam War having constructed ...
Crystal radio receivers are a very simple kind of batteryless radio receiver. They do not need a battery or power source, except for the power that they receive from radio waves using their long outdoor wire antenna. Sharp Electronics' first electrical product was a batteryless crystal radio introduced in 1925.
World War 2 created widespread urgent need for radio communication, and foxhole sets were built by people without access to traditional radio parts. A foxhole radio is a simple crystal sets radio receiver cobbled together from whatever parts one could make (which were very few indeed) or scrounged from junked equipment. Such a set typically ...
A crystal set receiver consisting of an antenna, a variable inductor, a cat's whisker, and a filter capacitor. A crystal receiver is very simple and can be easy to make or even improvise, for example, the foxhole radio. However, the crystal radio needs a strong RF signal and a long antenna to operate.
A simple crystal radio with no tuned circuit can be used to listen to strong AM broadcast signals. An early form of envelope detector was the crystal detector, which was used in the crystal set radio receiver. A later version using a crystal diode is still used in crystal radio sets today.
A buzzer circuit, powered by a BA-4 battery, was mounted in the box cover and used to adjust the crystal. The set was compact and mounted in a wooden box, type BC-14. The lid of the box held the buzzer circuit, detectors, a screwdriver, two P-11 telephone headsets, spare parts, extra crystals, and an operating manual, “Radio Pamphlet No. 3 ...