The Non Directional Beacon (NDB)

design is primarily for use as a locator

in aid of final approach. The NDB 436

radiates vertically polarized signals in

the frequency range of 190 to 550

kHz. The coverage volume is typically

omnidirectional in the azimuth plane.

The navigational signal contains no

coded information except an

amplitude modulated Morse code,

periodically repeated, which identifies

the transmitter. The airborne Direction

Finder indicates to the pilot the

direction of maximum signal strength,

which points directly towards the

ground station.

Due to the frequency band used, the

antenna is always electrically short

with consequently very low radiation

efficiency.

Therefore a suitable Antenna Tuning

Unit (ATU) is required to properly

match the transmitter to the antenna.

In addition, the ATU automatically

compensates for antenna variations that

take place due to weather conditions

etc. The ATU can operate into various

antenna types such as mast, monopole

whip or symmetrical T.

The NDB 436 is designed in full

compliance with ICAO Annex 10 with

a transmitter power output of 100 Watts.

It is conceived as a full dual system,

but can be supplied in reduced

redundancy configurations (i.e. with

single transmitter, single monitor, or

both). It easily interfaces with a MSK

modulator for DGPS applications. The

NDB 436 can be connected to a variety

of power sources such as solar power.