Option 1 – This option provides calibrated preselection to the first (1st) mixer for the 1.7 to 18 GHz frequency range and limiter protection below 1.8 GHz. With a tuned front-end, you can concentrate on the real signal of interest. The preselector operates with the Tektronix High Performance Waveguide Mixers as listed in the Operator’s Manual, (included). At 50 kHz – 1.8 GHz, LO emissions specifications are improved to better than –70 dBm, and there is a limiter to help protect the front-end mixer from burnout on this band. Option 2 – This option provides digital storage. Multiple memory (A&B) display storage is provided with: Save A, Max Hold, B memory minus Save A memory, digital display averaging, and storage bypass for non-store display. Compare current signals with previously recorded signals, perform drift measurements, or make swept source measurements without “hauling out” additional gear. Option 3 – This option provides first (1st) local oscillator stabilization by phase locking to an internal reference to reduce residual FM when narrow bands are selected. The microcomputer automatically selects phase lock for a span/division of 50 kHz or less in the 50 kHz – 7.1 GHz bands, 100 kHz or less in the 5.4 – 18.0 GHz band, and 200 kHz or less in the 15.0 – 60 GHz bands provided Tektronix High Performance Waveguide Mixers are utilized. This option also adds a 100 Hz resolution filter. The instrument characteristics that are changed are listed in a table in the Operator’s Manual, (included).