Specifications

288 Chapter 10

Block Diagrams

RF Analyzer Section

Frequency Conversion

The A2A115 Downconverter, see Figure 10-3 on page 290, produces an

IF of 114.3, 385.7 or 614.3 MHz. The LO is provided by the A2A22

Receiver Synthesizer, see Figure 10-4 on page 291. The IF frequencies

developed are as follows in Table 10-1.

Filters are automatically switched in to remove image and other

interfering signals. The frequency ranges of the filters are as follows:

• 150 MHz low-pass

• 150 MHz - 386 MHz bandpass

• 350 MHz - 650 MHz tunable bandpass

• 650 MHz - 1000 MHz tunable bandpass

• 1400 MHZ - 2200 MHz tunable bandpass

Modulation Measurement

The A2A21 Receiver assembly demodulates the IF into its FM, AM, and

SSB components, see Figure 10-5 on page 292. The demodulated signal

is sent to the Audio Analyzer section for measurement.

Table 10-1 IF Frequencies

Input RF (MHz) 1st LO (MHz) IF (MHz)

0 to 385.7 614.7 to 1000 614.3

385.7 to 800 500 to 914.3 114.3

800 to 1000 685.7 to 885.7 114.3

1400 to 2200 1014.3 to 1814.3 385.7