Schwarzbeck HFRAE 5161 Passive Magnetic RX Loop Antenna

The Loop Antenna for magnetic fields was designed for medium to high-level fieldstrengths in the frequency range 70 kHz (10 kHz) to 120 MHz. The application is without problems due to the passive structure without electronic components or power requirements: H fields from 20 dBµA/m on are indicated with test receivers (50 Ω input, calibration in dBµV) or, with slightly less sensitivity, with spectrum analyzers. Add the log. antenna factor from the table (kH) to the dBµV reading of the receiver to obtain the magnetic field-strength level in dBµA/m.

For high field-strengths broadband voltmeters with 50 Ω input resistance (also power meters - observe overload risks) may be used. Voltage or power readings must be converted to voltage levels in dBµV (20 log(U [µV])) and added to the antenna conversion factor kE.

When far-fields are being measured, one has to add the conversion factor for efields (kE) in dBµV/m to the measured result of the receiver in dBµV.The conversion from magnetic field strength to fictive electric field strength does not depend on the frequency and is 51.5 dB (=20 log (377 Ω)).