According to Wikipedia:

Last contact26 October 1957[4]Decay date4 January 1958

Rick Tejera K7TEJ Saguaro Astronomy Club www.SaguaroAstro.org Thunderbird Amateur Radio Club www.w7tbc.org

On October 4, 2018, at 22:23, wa7dxz via AMSAT-BB amsat-bb@amsat.org wrote:

How long was Sputnik in orbit, and for how long was the signal on the air?Bobwa7dxz

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