Good working Signal Generator from H/P, Model 8640B with options 001 and 003.  0.5 to 512 MHz frequency range, +19 to -145 dBm output power range, low SSB phase noise, calibrated, metered AM, FM, and pulse modulation, internal phase lock/synchronizer,.digital frequency readout, external count capability to 550 MHz.  Option 001 is an internal variable audio oscillator, 20 Hz to 600 kHz.  Option 003 is reverse power protection.