5
.Menu Interpretation
33
Reference level located at the top of axis grid. Measurement
near the reference level would gain better accuracy, but input
signal amplitude should not exceed the reference level; if it
exceeds, the signal will be compressed and distorted, result in
wrong measurement. Analyzer’s input attenuation is related with
reference level, it can self-adjust to avoid signal compression.
Minimum reference level is -80dBm at Log scale under 0dB
attenuation.
5.3.2 [Attenuation Auto Man]
Sets the front attenuator of the RF input in order to permit big signals
(or small signals) to pass from the mixer with low distortion (or low
noise). It only works under internal mixer mode to adjust input
attenuator insider analyzer. In Auto mode, input attenuator is related
with reference level.
Key points:
When the preamplifier is On, the input attenuation could be set
up to 40 dB. You can adjust the reference level to ensure that
the specified parameters meet the requirement.
Modifying the reference level may cause an automatic change in
attenuation value; But the change of attenuation value won’t
influence reference level.
You can modify this parameter using the numeric keys, knob, or
direction keys.
Attenuator adjustment is to make the maximum signal amplitude
pass from mixer less than or equal to -10dBm. E.g. if the
reference level is +12dBm, the attenuator value is 22dB, then
the input level in mixer is -18dBm (12-22-8=-18), its mainly
purpose is to avoid signal compression. Switch [Input Atten Auto
Manual] to manual mode, adjust the attenuator manually. The
highlight under auto or manual stands for auto coupling and
manual coupling. When attenuator is under manual mode, press
[Input Atten Auto Manual] will match the attenuator and
reference level again.
Note: Maximum input signal amplitude of input attenuator (10dB
input attenuation at least) is +27dBm, higher power signal will
damage input attenuator or mixer.
