Many thanks to SRAA contributor, Colin Newell, who shares two recordings from the late 1970s of the pirate radio station RX4M The Voice of Clipperton. 

Colin recorded both of these station IDs from British Columbia, Canada, using his cassette recorder. Colin also notes that he may be the only person to have ever recorded RX4M off-air. RX4M was inducted into the North American Pirate Radio Hall Of Fame in 2011.  The following is an excerpt from an article written by Andrew Yoder on the NA Pirate Radio Hall of Fame site :

RX4M (Radio Experiment on 40 Meters) put in more time and hours to overcome obscurity, only to quickly fall back into obscurity, thanks to a pirate-unfriendly location in Washington State. Even by the mid-‘80s, few DXers or pirate listeners had heard RX4M, and few remembered it.The first difficulty for RX4M to overcome was the poor communications of the late ‘70s. When the station began broadcasting in August 1979, there was no Internet and all DX news either was discovered via monthly bulletin or magazine, meaning a minimum delay of two months for information to be reported. The next problem was the Pacific Northwest. At the time, very few shortwave DXers and almost no pirate listeners were located in the region. Some young pirate listeners were networking in southern California, toward Los Angeles, but even that was a long haul from the Seattle area. Despite a nightly broadcast schedule and boasting two transmitters (20 and 100 watts), no DXers in either NASWA or the Newark News Radio Club (two of the largest shortwave clubs of the time, and two of the best for pirate news) reported RX4M until April 1980 on 7370 kHz.The few listeners who remember RX4M know it as possibly the only North American pirate to operate with a regular shortwave station, like a licensed outlet. It was on nightly from *0550-0630* UTC with a variety of programs produced by different station staff: News with Tony Giles, Post Office Box 80 with Aaron Richardson, DX Forum with Mickey Anderson, Let’s Talk Technical with Larry Adams, and the Good Morning Show with Jerry Nelson. Other time slots were filled with old-time radio programs, such as Burns & Allen, Jack Benny, Fibber McGee & Molly, Sherlock Holmes, Fred Harris & Alice Faye.[...]RX4M, the Voice of Cliperton, was never heard again and no shortwave pirate since has adopted its style. At a time when many DXers were bitterly anti-pirate, many reporters said that RX4M programming sounded very professional.