SWR-584C Instruction Manual
HF/VHF/220MHz SWR Analyzer
11
capacitive because the reactance exhibited by a capacitor tends to decrease as frequency
increases.
Standard vs. Measured Values:
Even though a
Standard Value
may be stamped on the
case, a capacitor rarely measure that value at RF because of ambient temperature,
manufacturing tolerances, and differences in the test frequency. The sensitivity to frequency
occurs because stray inductance compounding inside the device and along the leads running
to the analyzer's calibration plane form a series-LC circuit. Normally, this condition causes a
capacitor's value (in pF) to
increase
with frequency, and it may even reach infinity if the circuit
becomes
series-resonant
(X=0).
4.5 Measure Inductance (uH):
This function measures the reactance of an unknown inductor
in Ohms (
X
) at a given test frequency and computes inductance in
uH
. To measure
inductance:
[ ] Turn on the analyzer and allow it to boot to default mode (
R&X
).
[ ] Press
Mode
three times
to access
Inductance
and
wait for the working screen.
[ ] Adjust the
Frequency
switches and
Tune
control to the desired test frequency (
MHz
).
[ ] Using the shortest leads possible, connect the inductor to the
Antenna
jack.
Alternatively, you may use the same lead length used in the actual circuit so stray inductance
will be incorporated into the measurement.
[ ] Read
Reactance
(
X
L
) in Ohms on top line, and read
Inductance
in
uH
on the lower line:
[ ] Also, read Reactance (
X
L
) in Ohms on the analog
Impedance
meter:
Ohms
40 50 70 100 400
0 10 20
The measurement range for
Reactance
is 7-650 Ohms. Values falling outside that range will
prompt one of the following error messages:
Too low to measure (X<7) Parallel-resonant (X=0) Too high to measure (Z>650)
100.000 MHz
76
Inductance
in uH
100.000 MHz
L(Z)>650
100.000 MHz
L (X<7)
X
L
100.000 MHz
L (X=0)
X
L
100.000 MHz
L (Z>650)
X
L
