The Marconi IFR Aeroflex NAV750 is a self-contained bench test set for testing and calibration of airborne navigation and communication systems. This precision simulator generates and measures VOR, LOC, COMM, ILS (G/S), and Marker Beacon signals, eliminating the need for multiple external instruments in maintenance and repair operations.
Technical Specifications
RF Generator
• Frequency range: 108–156 MHz (25 kHz increments) and 329–335 MHz
• Frequency accuracy: ±50 kHz (108–156 MHz), ±150 kHz (329–335 MHz)
• Frequency resolution: 100 Hz
• Clock oscillator: ±0.02% (2.16 MHz)
• RF output level: −127 dBm to 0 dBm (1.0 dB steps)
• Manual frequency selection via thumbwheel; automatic sweep in 25, 50, 100, or 200 kHz increments
• Automatic channeling stops at 117.950 and 135.975 MHz
• External channeling input available via rear panel
• Phase-locked operation at all fixed and variable frequencies
Modulation
• AM depth: 0–98% (accuracy 0.5% max)
• Modulation frequencies: 30 Hz, 90 Hz, 150 Hz, 1020 Hz, 9960 Hz
• Modulation accuracy varies by type; example: 9960 Hz VOR 30% (±1.2%)
• External modulation input via rear panel, 50 Ω impedance
VOR Section
• Bearing selection: 12 preset bearings (30° increments) plus ±10° steps; continuous adjustment 0.01° or 0.05° increments
• Bearing accuracy: ±0.05°
• Tones: 90 Hz, 150 Hz, 9960 Hz; phase-locked to ±1° or phase variable
• Ident tone: 1020 Hz at 0–60% modulation
LOC/GS Section
• Deviation: ±0.046 DDM, ±0.093 DDM, ±0.155 DDM
Physical
• Weight: Approximately 26 lbs
– Key Features
• Dual-band RF generation with precision frequency control
• Multiple bearing and deviation presets for rapid signal simulation
• Phase-locked modulation tones for stable receiver testing
• Attenuator range supports low-level receiver sensitivity checks
• Manual and automatic frequency sweep modes
– Typical Applications
• VOR/LOC/ILS receiver calibration and maintenance
• Avionics repair facility bench testing
• Marker Beacon and COMM system validation
• Receiver sensitivity and accuracy verification
– Compatibility & Integration
External channeling and modulation inputs enable integration with automated test systems and external frequency controllers.
