User's Manual

29.05.2007 Page 22 of 59
ASR500 Reader Operation
Figure 14: Example of tuning curve
Using third-party antennas
Antennas with an inductivity of 300µH ±5%, which have a quality factor equal to 140 at 134
KHz, can be tuned to the ASR500 reader.
A Q factor greater than 140 may destroy the reader. A Q factor less than 140 may reduce read-
ing range.
At a frequency of 134 KHz the AC voltage may be as much as 500V peak to peak.
The environment influences the Q factor and the inductance of the antenna.
Please note that connection of a third party antenna means that the radio approval is automati-
cally void.