Product User Manual
Page 8
Model GA101x Series High Power E-H Tuner
2002-2003 Gerling Applied Engineering, Inc.
Modesto, CA
OPERATION
Basic Operation
The most common intended function of the high power E-H tuners
is to provide an impedance match to the process load. Operating
the tuner for this purpose is a procedure involving the adjustment of
either or both tuning plungers while monitoring power reflected from
the process load.
However, predicting which plunger to operate first or the effect each
plunger will have on producing an impedance match is nearly
impossible without the aid of additional impedance analysis
equipment. Thus, choosing which plunger to adjust at any point
during the tuning procedure is often a matter of either trial and error
or prior experience with a given load.
CAUTION:
Care must be taken to avoid operating the
microwave generator at power levels exceeding the rating of the
tuner. Excessive power levels can cause damage to the tuning
plungers.
Standard Tuning Procedure
A recommended tuning procedure for first-time matching of a given
load is as follows:
1. Slowly adjust one plunger in either direction while monitoring the
level of reflected power. If reflected power increases while
adjusting in one direction then reverse directions and continue
adjusting until the reflected power stops decreasing.
2. Repeat step 1 for the other plunger.
3. Return to the plunger adjusted first and re-adjust in whichever
direction causes reflected power to decrease. Continue
adjusting until reflected power stops decreasing.
4. Repeat step 3 while alternating between plungers until reflected
power no longer decreases by adjusting either plunger. Make
note of the plunger positions and the level of reflected power.
5. Return both plungers to the original positions and repeat the
process except to start with a different plunger. Continue until
reflected power has again been minimized and make note of the
plunger positions and reflected power level. Compare to the
results obtained in step 4 and then adjust the plungers to the
positions which gave the best results.
