On 31 March 2006 , the amateur radio operators from AMSAT Germany tracked and received data from Voyager 1 using the 20 m dish at Bochum with a long integration technique . On March 31 , 2006 , the amateur radio operators from AMSAT in Germany tracked and received radio waves from Voyager 1 using the 20 m dish at Bochum with a long integration technique .