An informal collaboration between the scientists at Argonne, KEK, and ISIS was initiated in 1996 on a prototype 2nd harmonic, low-impedance amplifier system for test on the ISIS synchrotron. The intent was to pool limited R&D funds to pursue a mutually beneficial study of interest to all three laboratories. The prototype low-output-impedance system was built and tested in Japan during the period from October 2000 to July 2002. The KEK laboratory provided the amplifier and cavity supply, the ISIS laboratory provided the cavity, and Argonne National Laboratory provided the power supply for the final tube. Preliminary tests of the fully assembled system have been successfully completed. A plan for follow on installation and tests at ISIS is under development.