Weston 686 type 10A Electron Tube Analyzer. This is not another tube tester, but a true laboratory instrument for testing tubes under exact operating potentials. It tests for mutual conductance at the manufacturer's rated operating condition. Precision tube matching at all parameters can be conducted. Experimental tube circuits can easily be set up for study. Also tests for hot and element shorts leakage. The main panel is 26"H x 19"W, and includes all necessary jumper cables. 13 sockets handle tubes from the earliest 4 pin types through 9 pin miniature tubes. There are SIX precision meters that measure all parameters. Includes copy of the original operating manual and the original tube set up manual. Price $1250.