The 7L13 Spectrum Analyzer is a high-performance communication spectrum analyzer that plugs into and operates with the 7000-Series mainframe oscilloscopes. It is a swept front end analyzer that displays absolute amplitude information of signals within the frequency span of 0 Hz to 1.8 GHz. Time domain characteristics, within a 3 MHz bandpass, can also be displayed. Important features of the 7L13 are: 1) Greater than 70 dB dynamic range. 2) Sensitivity down to —128 dBm. 3) Resolution capability from 3 MHz to 30 Hz. 4) Incidental FM’ing less than 10 Hz. 5) Fully calibrated display modes of either 10 dB/Div, 2 dB/Div, or Linear; and a calibrated reference level in dBm. 6) Calibrated sweep spans from 100 MHz/Div to 200 Hz/Div. 7) Digital frequency readout. 8) Full range of video filtering for noise averaging. 9) Baseline clipping to subdue the bright baseline of displays when photographing. 10) Pulse stretching, to enhance pulsed spectra when using wide frequency spans and resolution bandwidths. 11) Access for a tracking generator. 12) Frequency and amplitude reference calibrator. If the 7000-Series mainframe features crt readout, the signal parameters and other pertinent information, such as resolution bandwidth, video filtering, and frequency span, are displayed on the crt readout to simplify the operation of the instrument. Records can then be made of pertinent data by photographing the display. The analyzer requires three plug-in widths in the 7000- Series mainframe. ELECTRICAL CHARACTERISTICS The following characteristics and features of the 7L13 Spectrum Analyzer are applicable after a warmup period of 30 minutes or more. CENTER FREQUENCY Range: 1 kHz to 1.8 GHz. Resolution of the Center Frequency Indicator: Within 1 MHz. Accuracy: ±(5 MHz + 20% of the Freq Span/Div). The center frequency is indicated by LED readout on the 7L13 and crt readout when the 7000-Series mainframe has this feature. FREQUENCY SPAN Calibrated spans from 200 Hz/Div to 100 MHz/Div in a 1-2-5 sequence, plusO Hz and MAX SPAN positions. In the 0 Hz position, the analyzer is a fixed tuned receiver for time domain analysis. In the MAX SPAN position the frequency span is approximately 1.8 GHz. Accuracy: Within 5% of the indicated frequency separation. Linearity over the center 8 divisions is within 5%. RESOLUTION Six resolution bandwidth selections from 30 Hz to 3 MHz, in decade steps, are provided. Resolution bandwidth may be coupled or uncoupled from the frequency span selector. Bandwidth accuracy: Resolution bandwidth, at the 6 dB down point, is within 20% of the resolution selected. Shape factor (60:6 dB ratio): 12:1 or better for 30 Hz resolution and 4:1 or better with resolution of 300 Hz or more except 3 MHz. Maximum bandwidth 60 dB down with 3 MHz resolution, is 13 MHz. Signal level change over the six resolution bandwidth selections is less than 0.5 dB. STABLITY (after a 2 hour warmup period) Within 2 kHz per hour at a fixed temperature, when x phase locked: within 50 kHz when not phase locked. INCIDENTAL FM (see Fig. 3-5) 10 Hz (peak-to-peak) or less when phase locked, and 10 kHz (peak-to-peak) or less for 5 seconds when out of phase locked mode. VIDEO FILTERING Three selections of video filtering; 10 Hz, 300 Hz and 30 kHz are provided for signal or noise averaging. DISPLAY LOG 10 dB/DIV: Provides a calibrated 70 dB dynamic range with an accuracy that is within 0.1 dB/1 dB to a maximum of 1.5 dB over the full dynamic range. LOG 2 dB/DIV: Provides a calibrated 14 dB dynamic range with an accuracy that is within ±0.4 dB/2 dB to a maximum of 1.0 dB over the 14 dB dynamic range. LIN: Provides a linear display from approximately 0.7/iV (100 dBm) full scale, to 7.07 volts (+30 dBm). Amplitude linearity is within 10% over the graticule height. REFERENCE LEVEL Reference level operation is in calibrated 10 dB steps from -110 dBm to +30 dBm, within ±2 dB. (Accuracy includes the attenuator and gain switching effects when the two are not offsetting each other.) Reference level operation below 100 kHz becomes limited to a range from +30 dBm to-50 dBm as the center frequency approaches 1 kHz. Reference level deviation, between display modes, is less than 2 dB from 2 dB/DIV to 10 dB/DIV and less than 0.5 divisions from 2 dB/DIV to LIN. This deviation is a function of the oscilloscope vertical linearity. An UNCAL indicator signifies when the display is not calibrated. DISPLAY FLATNESS +1 dB, —2 dB with respect to the level at 50 MHz, over any selected frequency span.