Profile: Ballantine Laboratories, Inc. deals with calibrators and automated systems. The BLI 6127B programmable oscilloscope calibrator provides a variety of signals of precise voltage, current, timing and wave shape. It can be operated manually or automatically, using the IEEE-488 interface and Scope-Cal™ automated software. The BLI 1620A transconductance amplifier provides current levels from DC to over 10 kHz for calibrating ammeters, current transformers and shunts. It converts a signal voltage applied to its input into a high resolution output current whose value is directly proportional to the input signal level.