Unless noted, all specifications describe the instru- ments’ warranted performance under the following conditions: 5-minute warm-up from ambient condi- tions, autocoupled controls, digital display, IF ADJ ON, REF LVL CAL adjusted, SECOND IF OUTPUT and 1ST LO OUTPUT terminated in 50 Ω. After a 30-minute warm-up, and over a temperature range of 20 °C to 30 °C, the preselector does not have to be peaked at each signal of interest; under these conditions factory preselector peak values are suf- ficient to meet all specifications. Typical perform- ance is nonwarranted. Supplemental characteris- tics are denoted by “nominal” and “approximately”; these constitute nonwarranted functional perform- ance information derived during the design process and are not tested on a continuing basis.