Yosemite Sam is a nickname for a mysterious number station that was first heard on December 19, 2004. Looney Tunes character Yosemite Sam’s voice is played during the transmission, hence the nickname ‘Yosemite Sam”. It transmits on four double side band (DSB) frequencies: 3700 kHz, 4300 kHz, 6500 kHz, 10500 kHz, they can be tuned into either LSB or USB modes, it’s essentially AM but without a carrier
The transmission will start on one of the frequencies. Then ten seconds later, it’s repeated on the next higher frequency, and so on, this goes on for two minutes. The entire pattern takes exactly two minutes, and always begins seven seconds after the hour.
Each transmission starts with what sounds like a data burst tha will last for 0.8 seconds, then the voice of Yosemite Sam can be heard saying “Varmint, I’m a-gonna b-b-b-bloooow yah t’smithereens!” The clip is said to have come from the Looney Tunes cartoon “Bunker Hill Bunny” which was made in 1949.
The Yosemite Sam station disappeared on December 23, 2004, but then returned in February 2005, on its previous frequencies and additional new frequencies, including those of time signals stations WWVH and frequencies of 10 and 15 MHz (and perhaps others).
The purpose and origin of the Yosemite Sam number station remains unknown.
Various reports seem to suggest that the transmitter site is probably in the desert near Albuquerque, New Mexico, United States. The Albuquerque location is another relation to Looney Tunes, Bugs Bunny often used the phrase “I knew I should have taken that left turn at Albuquerque.”