Dictionary of Meaning

<<Back
Please select a letter:
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0-9

AM stereo

*** Shopping-Tip: AM stereo
'''AM stereo''' is any of a number of mutually compatibility incompatible techniques for broadcasting stereophonic two-channel Audio frequency audio in the mediumwave band in a manner that is compatible with receiver (radio) receivers designed for standard amplitude modulation. There are two main classes of systems: independent sideband (ISB) systems, promoted principally by United States American broadcast engineer Leonard Kahn; and quadrature amplitude modulation (QAM) multiplexing systems (conceptually closer to FM stereo). Early experiments with stereo AM radio involved two separate stations broadcasting the left and right audio channels. This was not a very practical option, requiring a listener to have two radios tuned to each station. Synchronization was problematic, often resulting in a sort of ping-pong effect between the two channels. Reception was also likely to be different between the two stations—nevermind the fact that many listeners had unmatched receivers of different models or brands. In the early 1980s five competing AM systems went on air: * Motorola (C-QUAM) * Magnavox (PMX) * Kahn-Hazeltine (ISB) * Harris Broadcast (V-CPM) * Meduci (AMAX) AM stereo timeline highlights: * 1960 - AM Stereo first demonstrated on XETRA (AM) XETRA-AM, Tijuana, MX, using the Kahn ISB system. * 1963 - WHAZ runs a stereo program on eight AM stations, four on each channel. * 1984 - The FCC begins AM Stereo testing with five systems. Initially they select the Magnavox system. Their research is immediately accused of being flawed and incomplete. * 1993 - FCC makes Motorola's C-QUAM the AM stereo standard. This set off another series of lawsuits and accusations resulting in the FCC deciding that the marketplace should decide. The marketplace continues fighting it out, and this becomes a death blow to the possibility of AM stereo. A famous European transmitter using AM stereo is Transmitter Villebon sur Yvette Villebon sur Yvette on 864 kHz, which transmits Radio Bleue. AM stereo is popular in Japan because of the limited number of FM stations in that country, and in Australia possibly because AM stations are more suited to covering large sparsely populated regions than FM stations. After some short lived experiments, the Independent Broadcasting Authority decided not to adopt AM stereo in United Kingdom Britain. Some enthusiasts claim that AM stereo gives better Stereophonic sound stereo separation than FM stereo, but under skywave reception conditions, some AM stereo systems suffer from "platform motion"

External links

- Radio Bleue (French language French)
- AM stereo tuner source
- AM stereo enthusiasts website
- Another AM stereo enthusiasts website
- And yet another AM stereo enthusiasts website ja:AMã‚¹ãƒ†ãƒ¬ã‚ªæ”¾é€? Category:Radio Category:Broadcast engineering

*** Shopping-Tip: AM stereo