Wikipedia
KNIK-LP is a low-power commercial television station in Anchorage, Alaska, broadcasting on VHF channel 6, taking advantage of that station's audio signal on 87.75 MHz FM. The station is one of very few low-power television stations that operate predominantly as a radio station by way of the fact that many FM radio receivers can tune in a VHF channel 6 television audio carrier at 87.75 MHz. This technique is made more potent due to a formerly unforeseen interpretation of deregulatory language in FCC low-power television station regulations:
Sec. 73.653 Operation of TV aural and visual transmitters.
The aural and visual transmitters may be operated independently of each
other or, if operated simultaneously, may be used with different and
unrelated program material.
This means that KNIK-LP need not broadcast any particular image so long as it broadcasts a video signal and that the audio and video need not be technically synchronized.