The Keysight (Agilent HP) 8656B is a programmable synthesized signal generator operating in the 100 kHz to 990 MHz frequency range. Highly regarded for its reliability, performance, and cost-effectiveness, it provides precise output control with ±1 dB level accuracy and 0.1 dB resolution from +13 to -127 dBm. It features versatile AM/FM modulation capabilities (both internal and external) and a rapid frequency switching speed of under 35 ms, making it a staple instrument for RF design, manufacturing, and service environments.
Specifications
Frequency
| Parameter | Value |
|---|---|
| Minimum Frequency | 100 kHz |
| Maximum Frequency | 990 MHz |
| Frequency Resolution | 10 Hz |
| Phase Adjustment Resolution | 1° |
Output
| Parameter | Value |
|---|---|
| Maximum Output Power | +13 dBm |
| Output Power Range | +13 to -127 dBm |
| Phase Noise | < -114 dBc/Hz at 20 kHz offset, 500 MHz carrier |
Modulation
| Parameter | Value |
|---|---|
| Modulation | AM, FM |
General
| Parameter | Value |
|---|---|
| Reference Oscillator | 10 MHz (standard or Option 001 High Stability) |
| Interfaces | GPIB (IEEE-488) |
Frequency Specifications
| Parameter | Value |
|---|---|
| Frequency Range | 100 kHz to 990 MHz |
| Frequency Switching Speed | < 35 ms (to within 100 Hz of final frequency) |
| Reference Oscillator Frequency | 10 MHz |
| Reference Oscillator Aging Rate (Standard) | < ±2 x 10^-6 per year |
| Reference Oscillator Aging Rate (Option 001) | < 5 x 10^-10 per day (after 10 days warm-up) |
| Reference Oscillator Temp Stability (Option 001) | < ±7 x 10^-9 (0 to 55 °C) |
| External Reference Input Requirements | 10 MHz, level > 0.15 Vrms into 50 ohms |
| Reference Output Level | 10 MHz, level > 0.5 Vrms into 50 ohms |
Amplitude (Output Power) Specifications
| Parameter | Value |
|---|---|
| Amplitude Range | +13 to -127 dBm |
| Amplitude Resolution | 0.1 dB |
| Output Impedance | 50 ohms nominal |
| Reverse Power Protection Limit | 50 W RF, 25 V DC (from 50 ohm source) |
Spectral Purity
| Parameter | Value |
|---|---|
| Non-Harmonic Spurious (offsets > 50 kHz) | < -60 dBc |
| SSB Phase Noise at 20 kHz Offset (500 MHz carrier) | < -114 dBc/Hz |
| RF Leakage | < 1 µV induced in a 2-turn, 2.5 cm loop, 2.5 cm from surface |
Amplitude Modulation (AM)
| Parameter | Value |
|---|---|
| AM Depth Range | 0 to 99% (for output levels <= +7 dBm) |
| External AM Input Sensitivity | 1 Vpeak for indicated depth |
| External AM Input Impedance | 600 ohms nominal |
Frequency Modulation (FM)
| Parameter | Value |
|---|---|
| FM Deviation Range | 0 to 99 kHz |
| FM Resolution | 100 Hz (deviations < 10 kHz); 1 kHz (deviations >= 10 kHz) |
| FM Accuracy | ±(5% of setting + 10 Hz) (at 400 Hz and 1 kHz rates) |
| FM Rate/Bandwidth (AC) | 20 Hz to 100 kHz (3 dB bandwidth) |
| FM Rate/Bandwidth (DC) | DC to 100 kHz (3 dB bandwidth) |
| External FM Input Sensitivity | 1 Vpeak for indicated deviation |
| External FM Input Impedance | 600 ohms nominal |
Internal Modulation Source
| Parameter | Value |
|---|---|
| Internal Modulation Frequencies | 400 Hz and 1000 Hz |
| Internal Modulation Frequency Accuracy | ±3% |
Rear and Front Panel Connectors
| Parameter | Value |
|---|---|
| RF Output Connector | Type-N female (front panel; rear panel with Option 002) |
| External AM Input Connector | BNC female (front panel) |
| External FM Input Connector | BNC female (front panel) |
| External Reference Input Connector | BNC female (rear panel) |
| Reference Output Connector | BNC female (rear panel) |
| GPIB Interface | 24-pin IEEE-488 (rear panel) |
General and Environmental Specifications
| Parameter | Value |
|---|---|
| Operating Temperature Range | 0 to 55 °C |
| Storage Temperature Range | -55 to +75 °C |
| Power Supply Voltage | 100 / 120 / 220 / 240 V AC (+5%, -10%) |
| Power Supply Frequency | 48 to 440 Hz |
| Power Consumption | < 125 VA |
| Dimensions (W x H x D) | 425 mm × 133 mm × 520 mm |
Ordering Options and Accessories
| Parameter | Value |
|---|---|
| Option 001 | High-Stability Oven Reference Timebase |
| Option 002 | Rear-panel RF Output and Modulation Inputs |
| Option 907 | Front Handle Kit |
| Option 908 | Rack Flange Kit |
| Option 909 | Rack Flange and Front Handle Kit |
Protection
| Parameter | Value |
|---|---|
| Maximum DC Reverse Voltage | 50 V dc |
Technology
Synthesized RF Signal Generation
Applications
RF transmitter and receiver testing, general laboratory use, automated test systems
Looking for the Keysight Technologies (Agilent HP) 8656B?
Tell us what you need. We're building a network of equipment dealers and will get back to you if we can help source it — no obligation.
Selling this kind of equipment? Sell with us