NARDA ADFA Handhabung Seite 37

Measurements with the ADFA
The ADFA has a vertical polarization and, therefore, receives the
vertically polarized signals optimally. For horizontally polarized
signals, a significant reduction of the signal level has to be considered.
 Be aware of the polarization of the measured signal.
The ADFA has a built-in electronic compass. Once the electronic
compass in the ADFA is exposed to magnets, magnetic objects or
strong magnetic fields, it can be permanently distorted. In such cases,
it must be recalibrated by Narda to obtain reliable bearing results.
 Keep the ADFA away from magnets or electrical devices that contain
magnetic objects or can generate strong magnetic fields, such as high
current conductors, mobile phones, speakers, motors or heaters.
 Always keep your ADFA away from such objects, even when the system
is switched off.
Metallic stickers in the sensor area of the ADFA can lead to
measurement errors, in particular to an underestimation of the
electromagnetic field strength and misleading bearing results.
 Do not attach metallic materials (for example, labels) to the radome of
the ADFA.
Do not use the built-in magnetic compass when the ADFA is mounted
on a vehicle roof. The magnetic mount adapter as well as the vehicle
roof interfere with the compass's measurements of the earth's
magnetic field.
 Determine the north with the help of your GNSS receiver.
 For more information, refer to the ADFA topic in the SignalShark online
help.
Use of a defective ADFA
Through a defective ADFA, it is possible that existing high radiation
values cannot be detected and bearing results are misleading.
 Before using the ADFA, check the ADFA with a test source such as a
Public Mobile Radio (PMR) Walky-Talky at 433 MHz.
 Make sure that you know the frequency, field strength and polarization to
be expected before starting an RF radiation measurement.
Narda Automatic DF Antenna 37