2635 manual - BK Precision

(UNCAL display). In this case, SPAN needs to be reduced. With
the aid of the Center Frequency (CENTER FREQ.) setting, first
the signal to be tested needs to be centered on screen, then the
SPAN can be reduced.
If SPAN is reduced without the signal to be tested centered it is
possible for the signal to end up outside of the screen.
The Video Filter should not be used - if possible - when pulsed
signals are measured in order to prevent measuring errors
(transient response time).
(20) ATTN:
The buttons to set the input attenuation are marked ATTN. By
pushing the UP and DOWN buttons, the attenuation can be set
from 0 dB to 40 dB in 10 dB steps.
To enter 0 dB attenuation, it is neccessary to push button long,
this is for protection of the input stage, so this setting can’t be
set accidentally.
Remark:
For reasons of protection of the input stage, the instrument will
always set an attenuation of 10 dB when switched on.
It needs to be pointed out again that the maximum allowable
input voltages may not be surpassed. This is especially important,
as it may be possible that the spectrum analyzer will display only
part of a signal under test, if other input signals are present but
not visible at current span.
(21) REFERENCE
With rotary knob REFERENCE the so called reference level is
set, to this level all amplitude readings on screen are referenced.
The reference level is always at the topmost horizontal graticule
line. Depending also on attenuator setting, the reference level
may be set between –99.8 dBm and +13 dBm.
(22) INPUT:
50 Ω Input of Spectrum Analyzer. Without attenuation of input
signal the maximum allowable input voltage is ±25V DC or
+10dBm AC respectively. With a maximum attenuation of the
input signal (40dB) +20dBm is allowed. These values may not
be exceeded, otherwise the input stages will be damaged.
Subject to change without notice
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