Download HP 71910A - User`s Guide

Demodulated outputs are available at the front panel
The front-panel VIDEO connector provides AM and pulse demodulation. Option 004 provides
additional I/Q outputs and Option 005 provides an additional FM output. Refer to Chapter 3
for examples of processing these signals.
Option 004 instruments (together with an external oscilloscope in XY mode), provide a
convenient method of identifying modulation formats such as 8 PSK, 16 QAM, and 64 QAM.
With typical receivers, the constellations \spin" due to the oset in frequency between the
receiver and the signal. This makes format identication very dicult. But, because of the
wide-bandwidth surveillance receiver's 1 Hz frequency tuning, this spinning movement can be
slowed to the point where it is almost stopped.
256 QAM Constellation Displayed on Oscilloscope
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