Reflection Standard - Deepace KC901M User Manual

3.4 Calibration before S11 Measurement
Function S11 has multiple display modes yet it needs calibration once only, given
that the calibration parameters can be used in all modes.
User calibration should be done in the following situations:
Verifying important devices (e.g. antennas for broadcasting and TV station).
DUT fails to directly connect to the instrument, where necessitates extra cables.
After calibration, test if the curve of open and load are shown normally. If there
are some obvious errors, redo the calibration. In VSWR mode, curves in an open
circuit should be over than 10; when connecting to the load, it should be under 1.2.
NOTice
Executing calibration at the far-end of the external cables, under the condition
which the external cables' electric lengths exceed one half of the wave length of the
frequency (STEP), user needs to increase the sweeping points (or reduce SPAN)
before the calibration to avert the phase aliasing. For example, STEP 3MHz converting
to wave length equals 100m. The external cable must be less than 35 meter (Electric
length = cable's actual length/speed factor).
Choose "Re CAL" in mode S11 and then follow the operation tips.
DUT can sometimes be a printed circuit, or a device which cannot be connected
with a coaxial connector, therefore users need to strip off testing cable's end and then
solder it on the DUT. In situations of this kind, user can do the open-short calibration
before connect the DUT. Operating the open-short calibration, users should solder
coaxial cables' core wires on the shielding layer; in an open circuit, users should
separate the cables and hang them in the air. When the instrument is loading (LOAD),
choose "Skip" in the soft menu.
3.5 Reflection Calibrator
S11 abides by SOL calibration, in which the three capital letters respectively
represent 3 types of calibrators: short, open and load.
KC951011/KC951012 is the SOL calibrator that we (Kexinshe) produced. Users can
also use other proper calibrators, but keep in mind that the terminal effect of the
chosen calibrators must be small enough since there is no compensation for KC901M
(non-commercial version). KC951011's nominal electric length is 5.26mm and
KC951012's one is 0. If a user chooses other standard, he/she needs to input the
value of the actual electric length in the FUNC interface.
To attach the calibrator tightly with instrument, clamp it hard with the thumb and the
index finger. If using a torque spanner, the torque should better be 135M.cm.
Calibrator are expensive accessories that should be taken good care of and better be
scrutinized from time to time. Check the adaptors before calibration to prevent
unexpected damages to the calibrator.
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