HS-IIIi Tuner The HS-IIIi tuner normally operates in the WIDE IF bandwidth mode for low noise and wide frequency response. When a strong undesired signal is detected, however, it automatically operates in the NARROW IF bandwidth mode to avoid interference and noise. The accuracy of switchover between WIDE and NARROW is high because a microcomputer monitors the ambient field strength and multipath reflections, as well as noise level. Enjoy steady radio reception and clear, powerful sound in or out of town.