A K-band (18-25 GHz) reflected-wave ruby maser (Moore and Clauss 1979) has been borrowed from the National Radio Astronomy Observatory for radio astronomy use on the NASA 64-m antenna of the Deep Space Network at the Tidbinbilla Tracking Station, near Canberra. The purpose of the installation is to provide additional sensitive spectral line, continuum, and VLBI capabilities in the southern hemisphere. Previous measurements at 22.3 GHz (λ = 13.5 mm) determined that the Tidbinbilla 64-m antenna has a peak aperture efficiency of ˜22%, a well-behaved beam shape and consistent pointing (Fourikis and Jauncey 1979). Before installing the maser on the antenna a cooled (circulator) switch was added to provide a beam-switching capability, and a spectral line receiver following the maser was incorporated. The system was assembled and tested at JPL in late 1980 and installed at Tidbinbilla early in 1981. We give here a brief description and present some of the first line observations made in February and March 1981. Extensive line and continuum observations are planned with the present system and a program is under way to determine the telescope pointing characteristics.