The HP/Agilent 4935A Transmission Impairment Measurement Set is a portable analog test instrument for qualifying telecommunication circuits in voice, data, and broadcast services. It delivers comprehensive transmission impairment analysis across a 110 kHz bandwidth, identifying circuit faults and validating performance against North American standards. The 4935A qualifies local loops for Digital Data Systems (DDS) up to 56 kbps and performs rapid field measurements without bench-based infrastructure.
Technical Specifications
Measurement Range & Bandwidth
• Frequency measurement: 20 Hz to 110 kHz
• Transmission level: −40 to +13 dBm
• Receive level: −60 to +13 dBm
• Bandwidth: 110 kHz
Measurement Capabilities
• Signal level and frequency detection with user-definable frequency storage and recall
• Circuit noise and noise-with-tone analysis
• Signal-to-noise ratio (S/N) calculation
• Three-level impulse noise detection and quantification (with or without tone)
• Noise-to-ground measurement
• Peak-to-average ratio (P/AR) assessment (optional)
Filter Options
C-message, Psophometric (P.53), 3 kHz flat, 275–3250 Hz flat, Program, Sound unweighted (J.16), 15 kHz flat, Sound weighted (J.16), 50 kbit, 1010 Hz notch, and 820 Hz notch (1020 Hz optional).
Frequency Storage
Four permanently stored frequencies: 404 Hz, 1004 Hz, 2804 Hz, and 2713 Hz. Four additional user-assignable temporary storage slots.
Connector & Interface
WECO 310 jacks for transmit/receive. Optional pairing with HP 4925B bit error-rate test set provides RS-232/V.24 and V.35 interfaces.
Impedance Configuration
Independent transmit and receive impedances with bridged mode options.
– Key Features
• Portable 5.0 kg (11 lb) form factor without battery; 6.5 kg (14 lb) with battery
• Compact dimensions: 127 mm (H) × 279 mm (W) × 381 mm (D)
• User-configurable measurement parameters
• Real-time noise and impulse detection
– Compatibility & Integration
Compliant with Bell (BSTR 41009) and IEEE (IEEE 743-1984) standards for North American telecommunications networks. The 4936A variant provides CCITT recommendation compatibility for international applications.
