Abstract: A portable telephone answering device which fits over the cradle of a telephone handset and receives the handset with a speaker adjacent the handset microphone and a microphone adjacent the handset speaker. An outgoing message can be recorded on one track of a multi-channel loop of tape. When ringing is detected, the telephone plungers are released and the outgoing message played. Next the unit records an incoming message on another track. A metallic splice on the loop serves as a reference. The number of channels on which an incoming message has been recorded are counted and the count incremented only if audio signals are detected indicating a message was left.

Abstract: An automatic printed circuit board tester in which a laser beam is directed onto and scanned around solder pads and foil regions of a printed circuit board, and errors in structure are determined by detecting patterns of scattered light and comparing these patterns with similarly obtained ones from a properly constructed board.

Abstract: An apparatus for measuring the effectiveness of stray light suppression light shields and baffle arrangements used in optical space experiments. The light shield and baffle arrangement and a telescope model are contained in a vacuum chamber. A source of short, high-powered light energy illuminates portions of the light shield and baffle arrangement and reflects a portion of same to a photomultiplier tube by virtue of multipath scattering. The resulting signal is transferred to time-channel electronics timed by the firing of the high energy light source allowing time discrimination of the signal thereby enabling the light scattered and suppressed by the model to be distinguished from the walls and holders around the apparatus.