It is probably KPH and not a Pirate Beacon: "The station transmitting on 7467 kHz is the KPH Maritime Radio Receiving Station at Point Reyes, California, which operates as a functioning museum run by volunteers. It is the last active commercial Morse code station in the U.S. and sends out news, weather, and other messages on various frequencies on Saturdays."
I doubt KPH is sending distorted Morse Code and suspect it is your receiver having problems.