interference eliminator การใช้

Family Radio Service ( FRS ), PMR446 and other consumer-grade " bubble pack " radios often include a feature called " Interference Eliminator Codes ", " sub-channels ", or " privacy codes " the latter two being especially misleading as, contrary to what sales literature may say, they do not afford privacy or security, but serve only to reduce annoying interference by other users or other noise sources; a receiver with the tone squelch turned off ( e . g ., frequently done by selecting code " 0 " ) will hear everything on the channel.