Chassis Interior Layout; Functional Description; Rf Output Level; Frequency - Aeroflex NAV 2000R Operation Manual

4.2.3 CHASSIS INTERIOR LAYOUT

The chassis interior consists of the power supply, card cage, and interconnection wiring.
The power supply voltages are +5 V, -12 V, and +15 V.
The card cage is built around the motherboard which has filtering and voltage regulation. It provides +5 V
digital and +5 V analog voltages and regulated -5 V digital and -5 V analog voltages. The system
computer board, DSP board, and RF module plug into connectors located on the motherboard. The
synthesizer module plugs into a ribbon cable and a RF cable coming from the motherboard

4.3 FUNCTIONAL DESCRIPTION

The output parameters of the NAV 2000R are discussed in the following sections.

4.3.1 RF OUTPUT LEVEL

The RF Output level control is provided by an automatic leveling loop and a programmable step
attenuator. The programmable step attenuator and leveling loop provide 0.1 dB steps. These are
controlled automatically by the system computer and drivers located on the audio board of the RF
Modulator Module and found on the front panel of -50 models. The RF output is found on the edge of the
RF Modulator Module accessible from the rear panel on -60 models. The output can be set from 0 dBm
to -127 dBm. The leveling loop is temperature and frequency response compensated.

4.3.2 FREQUENCY

The RF frequency coverage provided is .15 MHz to 450 MHz. This is generated within the synthesizer
module. The output level of the synthesizer is maintained at -20dBm. A 10 MHz TCVCXO is used as the
internal frequency standard. An external standard of 10 MHz may be applied at the TIMEBASE, 10 MHz
INPUT. Sensing a signal applied at the 10 MHz INPUT, the synthesizer will automatically switch, phase
locking the internal standard to the applied external standard.

4.3.3 VOR SIGNAL GENERATOR

The VOR audio signal is generated by the DSP board and is used to amplitude modulate the RF input
signal. The VOR signal is computed by the DSP and consists of a 9960 Hz tone, frequency modulated at
30 Hz, summed with a 30 Hz tone. The phase relationship between the 30 Hz FM of the 9960 Hz carrier
tone and the 30 Hz tone represents bearing information. To this, the DSP may add an identification of
either a 1020 Hz tone or 6 digit Morse code word at 1020 Hz. The composite audio signal is set for
percent modulation by the audio board of the AM Modulator Module.

4.3.4 ILS SIGNAL GENERATOR

The ILS signals consists of Localizer (LOC), Glide Slope (G/S), and Marker Beacon (MKR). The audio
signals for each is generated by the DSP board and amplitude modulate the RF input signal. The
conditions of the modulating audio composite signal is controlled by the system computer.
NAV 2000R SIGNAL GENERATOR - REV. 0 – JULY 26, 2007 - PG 4-2
Aeroflex Operation Manual