The exceptional frequency stability of the HP 8568B permits measurements with a 10 Hz bandwidth. This narrow resolution bandwidth yields noise levels as low as -135 dBm. Excellent frequency stability, sensitivity, and frequency reference accuracy combine to allow very accurate measurement of small signals in the presence of large ones. Multiple traces can be displayed to measure residual FM or drift, or to conduct real-time surveillance over a wide frequency range. Analyzer control settings can be saved in non-volatile memory. Complex measurement routines can be created on an external controller, stored in the analyzer's user RAM, and executed using a single custom softkey. By adding measurement accessories and options, the 8568B fits into many applications, including electromagnetic compatibility (EMC) testing, automated broadband signal surveillance, and component stimulus-response testing. The spectrum analyzer/test receiver is sensitive to low-level signals while providing overload protection from out-of-band signals. The result, for tests in the presence of high-level interference, is a measurement range 30 dB greater than that of the spectrum analyzer alone. (The improvement is even greater in the presence of broadband pulse-interference.)
The test receiver is easy to operate; simply use the spectrum analyzer controls without concern for preselector settings. The preselector automatically adjusts input-filter tracking, and the spectrum analyzer reports preselector operating conditions on the CRT display. For remote operation with a computer, the receiver system is fully GPIB programmable (GPIB is hardware, software, documentation, and support for IEEE-488 and IEC-625, worldwide standards for interfacing instruments.)
