Schwarzbeck NNBM 8126-A 890 Single Path Airborne Equipment LISN

The main application of the unsymmetrical single path LISN NNBM 8126-A 890 is the measurement of interference voltage in aircrafts in the HF-VHF range (0.1) 1-400 MHz.

The LISN was especially tailored for onboard mains with 890 Hz and a maximum voltage of 270 V. Under these extreme conditions the resistors of the LISN must be able to dissipate high power. Thus the commonly used vehicle LISN cannot be used.

The impedance characteristic is realized according to DO-160. The continuous current rating is 70 A, for a short time 100 A can be drawn.

The purpose of a LISN is to provide the device under test with energy, to carry the interference voltage to the EMI measurement receiver and to load the RF emitted by the device under test with standardized impedance.

The supply voltage has to be applied at the back panel of the LISN by using the wing terminals. The terminals have a diameter of 6 mm. The brass wing terminal for the ground can be removed, the red one for the conductor can’t.

Important! The operator has to make sure that the maximum current is limited according to the specifications for each frequency at the supply side. There is no fuse built into this LISN to protect the device under test!

The device under test has to be connected to the wing terminals at the front panel. The maximum current that can be drawn and the maximum voltage that can be applied can be looked up from the specifications.

The coaxial RF output has to be connected to the EMI measurement receiver using a BNC coaxial cable.

The external 10 µF capacitor is necessary to calibrate the LISN according to DO-160. It is available optionally.