The European horn you are hearing are the 335Hz and 400Hz you described. They combine to make the one tone. The American sounding horn is your fanfare horn (the switch in the center console). If that is blowing a fuse perhaps it is shorted somewhere or the horn is bad and is drawing too much current. I think that one sounds like crap anyways, I like the Euro sounding ones better.
93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K