Search results
Results from the WOW.Com Content Network
In 2006, the UK 27/81 Bandplan was introduced by the Republic of Ireland's Comreg as one of two sets of channels available for the Wireless Public Address System (WPAS) licensing scheme (similar to the UK's CADS – Community Audio Distribution System), as many Irish churches were already illegally using UK 27/81 CB equipment for this purpose ...
A Compatible sideband transmission, also known as amplitude modulation equivalent (AME) or Single sideband reduced-carrier (SSB-RC), is a type of single sideband RF modulation in which the carrier is deliberately reinserted at a lower level after its normal suppression to permit reception by conventional AM receivers. The general convention is ...
As originally constituted, what is now CB radio was Class D of the Citizens' Radio Service. Classes A and B were in the UHF radio band and served a similar purpose as Class D while Class C was interspersed among the current CB channels and used for remote control of devices, usually model craft (aircraft, watercraft, or road vehicles).
Illustration of the spectrum of AM and SSB signals. The lower side band (LSB) spectrum is inverted compared to the baseband. As an example, a 2 kHz audio baseband signal modulated onto a 5 MHz carrier will produce a frequency of 5.002 MHz if upper side band (USB) is used or 4.998 MHz if LSB is used.
The power of an AM radio signal plotted against frequency. fc is the carrier frequency, fm is the maximum modulation frequency. In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio ...
Brazil allows higher power levels than the US and most of Europe. New Zealand has two 40-channel HF CB bands available, the NZ-specific "NZ CB Band" 26.330–26.770 MHz (40 channels, AM and SSB allowed) and the standardized "mid band" 26.965–27.405 MHz (40 channels, AM and SSB allowed) for a total of 80 HF CB channels.
CB radio in the UK was deregulated in December 2006 by the regulatory body Ofcom, and CB radio in the UK is now license-free. The old MPT 1320 27/81 band will continue to be available for the foreseeable future. On 27 June 2014, changes were made by Ofcom to allow the use of AM & SSB modes on CB in the UK legally for the first time.
Reduced-carrier transmission is an amplitude modulation (AM) transmission in which the carrier signal level is reduced to reduce wasted electrical power. Suppressed-carrier transmission is a special case in which the carrier level is reduced below that required for demodulation by a normal receiver.