Kikusui KJM6335, Operation Manual, Page: 51 / 129

KJM6335 Operation 3-17
Operation When SYMMETRY mode is set to OFFSET
(OFFSET: lit)
The OFFSET mode lets you offset the slice level that automatically
follows up the symmetry level in AUTO action. An offset should
be adjusted by turning the variable resistor next to SYMMETRY
mode key, using an adjusting screwdriver.
Operation When SYMMETRY mode is set to MANUAL
(MANUAL: lit)
The automatic symmetry-level follow-up circuit is intended for an
RF signal before slicing. Input of a signal with brief rise and fall
times, such as square waves, limits the control range. For signals
whose duty ratio is not 50 %, control is entirely disabled. Thus,
when a sliced signal is input, the automatic symmetry level follow-
up circuit must be disabled.
To disable automatic symmetry level follow-up, set SYMMETRY
to MANUAL.
Slice level
Fig. 3-8
Fig. 3-8 shows the circuit with SYMMETRY mode set to
MANUAL. When the symmetry mode is set to MANUAL,
feedback control is disconnected and the slice level is given
directly from DAC. The range in which the slice level can be varied
is approximately 10 % to 90 %, where the peak-to-peak amplitude
of an RF signal is 100 %. However, as shown in the figure above,
because the input of the slicer is AC coupled, there is a difference
between the set slice level and the actual slicing level arising from
the duty ratio of the input signal.