https://www.youtube.com/watch?v=RVyFEMg0Kpg
TL;DW: There is a pot on the Famicom's RF box, which lets you adjust the Famicom's broadcast frequency. IF you turn that enough times, you can tune it to Channel 6.
another solution
https://www.youtube.com/watch?v=7r51L-_54bU
I've had a Famicom since 2004 and this is the first time I have heard about being able to adjust the RF signal from 95/96 to 5/6. Very cool!
Late reply, but it looks like my board doesn't have that green potentiometer. That kinda sucks D: