RIGOL DSA875 - Manual (Page 8)

RIGOL
DSA800 Options and Accessories 4
Preamplifier
PA-DSA832 (100 kHz to 3.2 GHz) / PA-DSA875 (100 kHz to 7.5 GHz) option provides
preamplifier for DSA832 / DSA875. When the signal under measurement is small,
turning on the preamplifier can reduce the displayed average noise level; therefore,
you can distinguish small signals from the noise.
Press AMPT at the front panel. Then, press RF Preamp to turn on or off the
preamplifier. An icon will be displayed on the left of the screen when the
preamplifier is on. As seen from the measurement result figures when the
preamplifier is off and on, small input signals can be measured by the analyzer when
the preamplifier is on.
PA Off
PA On