User's Manual

18/12/13 Page 8 of 8
ABR200 Antenna Tuning Manual
Example for an antenna, where the inductance is too high:
In that example the antenna inductance is too high and the coil is too much to the middle of the
ferrite (voltage too low and peak more to the left). Move the coil more to the top of the ferrite. In
case of air-coils or casted ferrite antennas, remove capacitance on your end. If all your
additional capacitance is removed and the inductance is still too high, remove 1 turn (or more
turns if necessary) from the antenna coil.
4 Capacitor selection
Because of their smaller size you should use SMD capacitors only. In case of SMD capacitors
only NP0 (C0G) types should be used. The rated voltage must be at least 500V. The required
capacities depend on the deviation of your antenna inductance from the target inductance
(275µH). This can be calculated fairly easy using the formula for the resonant frequency.
5 Trouble shooting
For any problem please contact us:
Agrident GmbH
Steinklippenstr. 10
30890 Barsinghausen
Germany
Telephone [phone]
FAX [phone]
Mail: [e-mail]