Search results
Results from the WOW.Com Content Network
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave.In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal.
The IF bandwidth was ±5 kHz, as the only goal at the time was to relay AM radio-quality audio. This transmission system used 75 μs audio pre-emphasis like the main monaural audio and subsequently the multiplexed stereo audio.
AM radio offered the highest sound quality available in a home audio device prior to the introduction of the high-fidelity, long-playing record in the late 1940s. Listening habits changed in the 1960s due to the introduction of the revolutionary transistor radio (Regency TR-1, the first transistor radio released December 1954), which was made ...
20 kHz. Occupies full bandwidth of region 2 or region 3 AM channel according to the existing frequency plan. This offers highest audio quality of the DRM30 standard (giving 30.6–72 kbit/s). 100 kHz for DRM+. This bandwidth can be used in band I, II, and III and DRM+ can transmit four different programs in this bandwidth or even one low ...
However in 2024, Ofcom expanded the allowed bandwidth to 9 kHz, giving a noticeable improvement in quality. With AM, it largely depends on the frequency filters of each receiver how the audio is reproduced. This is a major disadvantage compared to FM and digital modes where the demodulated audio is more objective.
But FM listening has increased to 61% and DAB decreased to 21% DAB listeners may also use AM & FM too. [ 10 ] The UK currently has the world's biggest digital radio network, with about 500 transmitters, two nationwide DAB ensembles and 48 local and regional DAB ensembles, broadcasting over 250 commercial and 34 BBC radio stations ; about 100 ...
A further concern to FM station operators was that AM stations could suddenly be in competition with the same high audio quality, although FM would still have the advantage of higher data rates (300 kbit/s versus 60 kbit/s in the HD Radio standard) due to greater bandwidth (100 kHz versus 10 kHz).
vestigial sideband modulation for analog video, and FM for analog audio; 8-VSB or OFDM for digital broadcast very high frequency (VHF) band I: Channels 2 through 6 are from 54–88 MHz (except 72–76 MHz). FM radio: 87.5–108 MHz, 76–90 MHz in Japan Frequency Modulation (FM) VHF band II: Usually music, due to the clarity and high bandwidth ...