My friend Art, KC2CA is doing some cleanup, and doesn't want to just throw this out It is a Tektronix 515A Oscilloscope he hand built himself when he worked at a Tektronix repair depot. He has spare parts, probes, and a spare CRT for it. It is a tube scope, and may need some TLC. Anyone interested, send me an e-mail. WB2HKK lengriff at optimum.net