The HP/Agilent 11960A EMC Preselector is a switched band-pass filter system that protects spectrum analyzers and EMC receivers from RF overload during electromagnetic compatibility testing. It narrows the bandwidth of energy presented to the analyzer’s first mixer, reducing mixer overload and measurement errors while improving dynamic range and frequency selectivity. The unit enables near-compliant CISPR 16 conducted emissions measurements and supports both conducted and radiated emissions testing across extended frequency ranges.
## Technical Specifications
• Conducted emissions range: 150 kHz to 30 MHz
• Radiated emissions range: Above 30 MHz (requires preamplifier)
• Band-pass filter configuration: Eight switched filters covering 150 kHz to 30 MHz
• Preamplifier gain: 30 dB with 8 dB noise figure
• Preamplifier sensitivity improvement: Up to 20 dB
• Attenuator: Switched 10 dB for radiated bands
## Key Features
• Reduces broadband and out-of-band RF overload before signal reaches first mixer
• Built-in preamplifier active above 30 MHz for radiated emissions measurements
• Switched 10 dB attenuator for overload verification on radiated bands
• Eight band-pass filter stages optimized for conducted emissions (150 kHz–30 MHz)
• Protects analyzer input stages from strong interfering signals
## Typical Applications
• Conducted emissions testing on switching-mode power supplies
• Radiated emissions measurements above 30 MHz
• CISPR 16 compliance verification
• Pre-filtering to prevent mixer saturation in broadband noise environments
## Compatibility & Integration
Designed for use with HP 8590EM series EMC analyzers and HP 8590E series spectrum analyzers. Supports automated test control via HP 11961A EMI measurement software.
