HP / Agilent 8656B/8657A/8657B
RF Signal Generators, Refurbished

• 100 kHz up to 2060 MHz
• Electronic attenuator on HP 8657A
• ± 1.0 dB level accuracy (typically ± 0.5 dB on HP 8657A)
• 50 Ω  reverse power protection on HP 8657A/B
• AM, FM, and optional pulse modulation
• Available Options, Below

Agilent / HP 8656B Shown

Product Information
Datasheet	710 KB
Ordering Info
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• 8656B Synthesized Signal Generator
• 8657A/B Synthesized Signal Generators

8656B Synthesized Signal Generator

The HP 8656B is a programmable synthesized signal generator that combines performance, quality, and economy, covering the 0.1 to 990 MHz frequency range.

The HP 8656B provides a ± 1.0 dB absolute level accuracy and 0.1 dB resolution with calibrated power levels over +13 to -127 dBm.  The output level can be offset to compensate for losses external to the generator.  RF leakage is well-shielded at < 1.0 mV and 25 Ω  reverse power protection guards against accidental damage.

The HP 8656B is capable of simultaneous AM and FM modulation.  The instrument provides internal 1 kHz and 400 Hz sources and also accepts external sources.  AM is ac-coupled, while FM can be either ac- or dc-coupled.  The dc-coupling is exceptionally stable (< 10 Hz/hour drift) and accurate (± 500 Hz center frequency accuracy).

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8657A/B Synthesized Signal Generators

The HP 8657A and 8657B offer excellent performance at an affordable price.  The HP 8657A coveres a 100 kHz to 1040 MHz frequency range while the HP 8657B covers 100 kHz to 2060 MHz.

The low residual FM (< 4 Hz at frequencies < 1040 MHz) and the excellent phase noise performance of these signal generators make them ideal for almost all measurements requiring test signals at adjacent or out-of-channel offsets.  Features such as carrier phase adjust allow you to characterize phase-sensitive devices such as phase detectors or phase interferometers, using precise 1-degree phse offsets with respect to another signal source.  Display blanking and nonvolatile memory-clear are also available for operation in secure environments.
These signal generators offer a wide dynamic output range, from +13 to -143.5 dBm, with unparalleled accuracy of ± 1.0 dB. The solid-state electronic attenuator in the HP 8657A is so reliable, it is backed with a five-year warranty against failure. The HP 8657A/B also have extremely sensitive circuitry.  Reverse power protection is provided standard for protection up to 50 Ω.

The HP 8657A and 8657B can combine modulation modes for AM/AM. Fm/FM, and AM/FM from both internal and external modulation sources.  AM is ac-coupled, while FM can be either ac- or dc-coupled.  The patented dc-coupling technique provides excellent long term stability (< 10 Hz/hour drift) as well as center frequency accuracy (± 500 Hz worst case).  When dc FM is enabled, SSB phase noise and residual FM performance are not degraded as with other generators. 
Pulse modulation is available with the HP 8657B Option 003. This option offers fast rise time and high isolation.  Rise times are 35 to 50 ns (typically 10 to 18 ns) and on/off ratios are 70 to 95 dB.  For pulse modulation coverage to 1040 MHz only, order the HP 8657B Option H60.

Up to 100 complete front-panel setups can be stored in the signal generator's memory for recall during testing.  These setups can be accessed sequentially by pushing one front-panel key or by using the rear-panel SEQ port.  The SEQ port can be connected to a foot switch or other operator-controlled device.

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