The Famicom itself came with one of those little grey box things, has Japanese written all over it, and it plugs into the same place the cable would plug into, in the back of most tvs. I suppose then that the only thing I actually own that will hook it up is that rf adapter, since it must not be av modded. =(
If you have the Famicom RF Switch
, then that probably won't work, either. Like others have said, get an RF adapter for an NES or Genesis or whatever and use that instead.