Anritsu spectrum master ms2711d User Manual page 114

Attenuator Functions
Attenuation adjusts the hand held spectrum analyzer input attenuator. In Auto mode, as the
reference level is increased, the attenuation is increased. In Manual mode, the input attenu-
ation can be adjusted using the keypad or the Up/Down arrow key. The attenuator range is
0 to 51 dB, in 1 dB steps. When Dynamic attenuation is selected, the instrument automati-
cally sets the input attenuation and preamplifier to achieve the best possible dynamic range
(See page 5-22).
IMPORTANT! Attenuation is normally a coupled function and is automatically
adjusted when the reference level changes. The reference level does not
change however, when the attenuator changes. The attenuator should be ad-
justed so that the maximum signal amplitude at the input mixer is –25 dBm or
less. For example, if the reference level is + 20 dBm, the attenuation should be
50 dB for an input signal of –25 dBm at the mixer (+20 – 45 = –25). This pre-
vents signal compression. The nominal gain of the preamplifier is +25 dB,
therefore always select attenuation values so that the input to the preamp does
not exceed –50 dBm.
NOTE: It is best to begin all measurements in AUTO attenuation mode.
Chapter 4 Measurement Fundamentals
4-3