The AN1840 is a microprocessor controlled, digitally synthesized spectrum analyzer. The AN1840 utilizes a numeric keypad, dedicated function keys, multitask Soft Function Keys and a high resolution LCD to display, enter and edit functions and data. Testing is done manually using external front panel controls or remotely through the RS-232 or IEEE-488 external interface. Microprocessor controlled memory allows storage and recall of parameters for each of the major testing modes as well as storage and recall of traces for signal comparison. 1-2 STANDARD FEATURES The AN1840 Spectrum Analyzer spans a range from 0 Hz to 26,5 GHz, at up to +30 dBm. The AN1840 input impedance is 50 Ω. The AN1840 operates as a Spectrum Analyzer, Frequency Counter, Digital Oscilloscope or AM/FM Receiver. 1-2-1 DISPLAY The AN1840 Display is a color VGA thin film transistor (TFT) LCD. The graticule area on the LCD has 500 horizontal pixels by 256 vertical lines. The Display shows up to 4 traces on the screen for comparison of live or previously stored signals. The 80 dB of dynamic range in the Logarithmic display mode is expandable to 120 dB. The Linear display mode provides dB units in addition to the regular power and voltage units, eliminating the need for external conversions. 1-2-2 MEASUREMENTS WITH THE AN1840 SPECTRUM ANALYZER The AN1840 tests and measures spectral purity, mixer products, modulation, carrier levels, suppression in Single Side Band Radios, harmonic levels, RF, EMI, FM deviation, AM % modulation, signal limits and distortion. The AN1840 is not limited to only these measurements. 1-2-3 INPUT LEVEL Maximum input level to the AN1840 is +20 dBm with <10 dB internal attenuation or +30 dBm with >10 dB internal attenuation. Maximum pulsed level is +40 dBm with >10 dB internal attenuation. CAUTION: SIGNALS EXCEEDING THE MAXIMUM INPUT LEVEL OF +30 dBm MAY CAUSE DAMAGE TO THE SPECTRUM'ANALYZER. 1-2-4 MARKERS The AN1840 Spectrum Analyzer incorporates the use of single and dual markers on the Display. Markers provide easy measurement of any portion of displayed signal. The Delta function shows differences in levels and time or frequency. Markers have peak search capability. 1-2-5 EXTERNAL ATTENUATION/GAIN OFFSET An offset value compensating for external attenuation and gain eliminates manual calculations. By setting an offset value equal to the sum of all external attenuation and gain factors, the AN1840 automatically displays true levels for signals requiring amplification or attenuation prior to entry into the AN1840. The offset also compensates for losses present when dealing with antenna factors. 1-2-6 FREQUENCY COUNTER The frequency counter provides selectable resolution at narrow or wide frequency span settings. Resolution is set to 1, 10, 100 or 1000 Hz.