Set The Basic Testing Parameter - Deepace KC901M User Manual

LowLo: Low local oscillation. The LO frequency is lower than the test frequency.
The image interference is from the low frequency side.
HighLo: High local oscillation. The LO frequency is higher than the test frequency.
The image interference is from the high frequency side.
If there is a signal showing in the same position on the screen whether in LowLo
mode or HighLo mode, this signal is probably a truly existed signal. On the contrary, if
a signal disappears in whichever mode, it is probably fake. If it shows in LowLo mode
but disappears in HighLo mode, the real frequency probably is 219.3MHz less than
the one that is shown. If it shows in HighLo mode but disappears in LowLo mode, the
real frequency probably is 219.3MHz more than the one that is shown.
When the frequency is lower than 200MHz, the local oscillation setting is invalid.
In this case, image interference can be filtered through low-pass filter.
NOTice
The factory calibrations of spectrum, transmission and field strength modes are
done in HighLo mode. The test may be inaccurate under LowLo mode.
2.7 Basic Testing Parameters Setting
To set the central frequency, press CENT first, then enter the frequence on the
number pad. If the desired frequency is near the current frequency setting, user
might use the wheel knob or press "+" "-".
To set the sweeping width, press SPAN.
To set the start frequency (START), use the combined key SHIFT+CENT.
To set the stop frequency (STOP), use the combined key SHIFT+SPAN.
If you are used to enter the frequency with start/stop frequency, you can set the
frequency control item as "START/STOP" in FUNC menu.
To adjust the reference level, press AMP or rotate the wheel knob clockwise or
counterclockwise, or simply use the "+" and "－" buttons.
While testing VSWR, button AMP is for adjusting the amplitude display division.
Pressing it repeatedly can switch the range among large, middle and small.
Sweeping point's setting is in the FUNC menu, shown as SWEEP POINT.
450 points in most situation and it's not necessary to change it in usual cases.
Instrument will choose the suitable frequency step (STEP) automatically according to
the sweeping width.
Sweeping speed can be set in FUNC menu with 3 levels: fast, middle and slow.
Usually the middle level is adopted. The fast level can increase efficiency by
shortening the sweep time, while reducing accuracy rate; if this is the case, there will
be a "*" shown on top right corner of the screen to notify user that the result is not
accurate.
The RBW of S11 and S21 need to be set in the FUNC menu. The smaller RBW is, the
slower the instrument sweeps. Normally factory calibration is executed on 10KHz
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