User's Manual

OBID
®
classic-pro Installation ID CPR.M02/ANT19
FEIG ELECTRONIC GmbH Page 17 of 20 Manual-M21001-3de-ID-B.doc
Use caution when the maximum value of the signal amplitude is reached at the minimum or maxi-
mum position of the trim capacitor (Fig. 3.4.3-3). This usually means the antenna is too severely
detuned by the surroundings and can no longer be fully compensated by the trim capacitor.
Beschriftung
Minimale
Kapazität
Maximale
Kapazität
Fig. 3.4.3-3: Minimum and maximum position of the trim capacitor C315
After the antenna has bee tuned, check it again for maximum range and any communication gaps.
NOTE:
• Notwithstanding the possibility of retuning the antenna as described here, the distance
between the reader and the surrounding metal surfaces must be at least 3 cm. Note that
even other circuit boards may act like metal objects depending on how much copper
they contain.
Labeling
Minimum
capacitance
Maximum
capacitance