2635 manual - BK Precision

Remark:
Is center frequency near lower end or SPAN increased, a spectral
line might be visible, possibly even without a signal connected.
It is commonly referred to as „Zero Frequency marking“ (ZERO
Peak) and is not unusual to be seen in analyzers using the superhet
principle. What is observed is the carrier of the 1st LO (1st
Oscillator) to become visible when the frequency comes within
the transmission range of the 1st IF filter. The level of the ZERO
peak mark may be different in each instrument and cannot be
used as calibration level.
(12) FINE
If the FINE button is pushed (LED is lit), frequency inputs (with
LED CENTER FREQ. lit) or Marker movements (LED MARKER is
lit) is performed in very small steps.
Pushing FINE again will cause the more coarse steps to be active
again. The FINE LED will be unlit.
(13) MARKER
In order to evaluate measurement curves, the instrument is
equipped with a running Marker (X). The Marker can be moved in
X-orientation via the tuning dial and follows the measurement
curve in Y-orientation. To activate the Marker, the Marker has to
be activated (LED lit) by pushing MARKER. The numeric indication
of marker frequency and amplitude is displayed on-screen (i.e.:
M 100.00MHz –29dBm). Push CENTER to leave MARKER mode
Remark:
The FINE function also affects the input for the Marker position.
(14) Tuning Dial:
The tuning dial either selects Center Frequency or Marker position,
depending on CENTER FREQ. or MARKER being activated.
(15) SPAN
The span of sweep of the analyzer is set via the two SPAN buttons.
The SPAN is displayed in the upper right-hand corner of the screen
and is marked with the letter „S“. At full SPAN (1000MHz) the
frequency axis is scaled in 100MHz steps per (vertical) graticule
line. Moving from the center graticule line towards the right screen
edge, the frequency increases by 100MHz per each line.
Therefore, the frequency of a displayed spectral line would be
500MHz + 5x100MHz = 1000MHz. The frequency reduces
22 Subject to change without notice