This camera can be used with any of the round-CRT HP 'scopes of the late 1960s.  It mounts on the CRT bezel, has diaphragm openings from ƒ/1.9 to ƒ/16, and shutter speeds from 1/50 to 1 second.  When last I checked Polaroid still manufactured a film pack that fit this camera.

The 355A/B (early 1960s) and 355C/D (late 1960s) are probably the most convenient and most desirable 50 Ω coaxial step attenuators ever built.  The 355A attenuates from 0 to 12 dB in 1 dB steps, from DC to 500 MHz.  The 355B attenuates from 0 to 120 dB in 10 dB steps, from DC to 500 MHz.  The 355C attenuates from 0 to 12 dB in 1 dB steps, from DC to 1 GHz.  The 355D attenuates from 0 to 120 dB in 10 dB steps, from DC to 1 GHz.  All four are rated for an average power input of 0.5 W and 350 V peak.

This versatile recorder can use inked, pressure-sensitive or electrosensitive rolls.  Eight speeds are available - 1, 2, 4 and 8 inches per minute, and 1, 2, 4 and 8 inches per hour.  The ten calibrated spans cover 5 mV to 100 V full scale.  Response time is ½ second or less for full scale deflection.  Accuracy is better than 0.2% of full scale.

The 712A was used by manufacturers to develop and prototype electronic equipment.  It contains three separate power supplies.  The high voltage supply is regulated, and provides 0 to 500 VDC at 200 mA maximum.  The bias supply is also regulated, and provides 0 to -150 VDC at 5 mA maximum.  The filament supply is fixed at 6.3 VAC at 10 A maximum.  My 712A is the core of a set of power supplies that I use when working on battery-powered radios of the 1920s.