RF Power Supply and Matching Box
5. Operation
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5-3-4. Adding a fixed capacitor
When Pr is at its minimum, it will be necessary to add a fixed capacitor if the position of the MATCH
variable capacitor is within 0% to 100% and the TUNE variable capacitor is near 0% or 100%. In this case, add
a capacitor as described next. Similar to adjusting the number of coil turns, open the maintenance side and
add a fixed capacitor. Then make sure screws aren't loose and close the maintenance side.
Recommended fixed capacitor to install inside the matching box (the fixed capacitor connected in parallel with
the TUNE variable capacitor)
SCF series (3 kW or less)
MC1C series (5 kW or more)
※
Fixed capacitor types may be changed without prior notice because of the end of production or other
reasons.
※
Shocks from falls or excessive stress may damage the fixed capacitor. Excessive tightening torque
may also damage it. Please tighten to a tightening torque of 147 N/cm or lower.
About the MATCH value
Adjust the MATCH variable capacitor by increasing or decreasing the coil's short circuits so that the
capacity is 20% to 80% when Pr is at its minimum.
About the TUNE value
Adjust the TUNE variable capacitor with a fixed capacitor so that the capacity is 20% to 80% when Pr is
at its minimum.
Contains high voltage generating parts, so work with extreme caution when making adjustments
using a high voltage probe.
Caution
Install inside the intermediate box.
Install in the fixed capacitor mounting stay
inside the matching box.
Figure 5-7 Adding a capacitor
Pr maximum with TUNE
variable capacitor at 100%
