HP / Agilent 3717A 70MHz Modulator – Demodulator

The HP/Agilent 3717A is a 70 MHz modulator-demodulator for intermediate frequency (IF) signal processing in microwave radio link systems. It performs precision modulation and demodulation at 70 MHz carrier frequency, supporting qualitative measurements at non-demodulating repeater stations and routine maintenance including white noise and TV waveform testing.

– Technical Specifications

Modulation/Demodulation: 70 MHz Intermediate Frequency

Baseband Frequency Response:
• 50 Hz to 10 MHz: ±0.2 dB
• 50 Hz to 20 MHz: ±3 dB

Spurious Response: −72 dBm0 (300 kHz to 10 MHz)

Square Wave Tilt (50 Hz): <1.0%

Differential Gain (4.43 MHz): ≤0.7%

Differential Phase (4.43 MHz): ≤0.7°

Noise Loading: ≤25 pWOp at 70 to 7600 kHz with 1800-channel emphasis (57 dB NPR)

Thermal Margin: Typically tolerates 6 dB overload without degradation

IF Output: +6 dBm

IF Input: +5 dBm

Baseband Output: −28 dBm/141 kHz (Telephony)

– Key Features

• Supports up to five installed emphasis networks (CCIR and BELL options available)
• Video emphasis networks for 525, 625, and 819 lines
• Core technology based on NorTel RA3 Mod/Demod package from Nortel Analog Microwave Radios
• Standard BNC connectors for IF input/output
• Option 004 adds WECO 477B equivalent connectors with 124 Ohm balanced telephony I/O
• Option 003 substitutes Siemens 1.56/6.5mm front panel connectors
• Option 100 provides HP-IB remote control capability
• Option 006 deletes modulator section (demodulator only)
• Rack mounting via HP part number 5061-0074 flange kit

– Typical Applications

Qualitative signal measurements, non-demodulating repeater station testing, white noise analysis, TV waveform testing, and communication system maintenance in microwave radio networks.

– Compatibility & Integration

IF connectivity via BNC or optional Siemens connectors. Telephony interfaces support standard 124 Ohm balanced impedance with optional WECO 477B equivalents. Remote operation available through HP-IB interface.