Which models in the SR700 series support two-channel measurements?

The Stanford Research Systems SR780 and Stanford Research Systems SR785 are two-channel dynamic signal analyzers, while the Stanford Research Systems SR760 and Stanford Research Systems SR770 are single-channel analyzers.

What is the primary difference between the SR760 and the SR770?

The Stanford Research Systems SR770 includes an integrated synthesized source for active signal stimulation, whereas the Stanford Research Systems SR760 is a passive spectrum analyzer without an internal source.

Can the memory of the SR780 be upgraded?

Yes, the Stanford Research Systems SR780 comes with a standard memory size of 8 MSamples, which can be expanded to 32 MSamples using Option 01.

Stanford Research Systems SR700 Series FFT Analyzers

4 models with full specifications from Stanford Research Systems.

The Stanford Research Systems SR700 series consists of high-performance FFT spectrum and dynamic signal analyzers designed for electrical engineering, acoustics, vibration testing, and noise analysis. This series is divided into single-channel units (the Stanford Research Systems SR760 and Stanford Research Systems SR770) and dual-channel units (the Stanford Research Systems SR780 and Stanford Research Systems SR785). These instruments provide high dynamic range and real-time bandwidth capabilities, allowing engineers to perform detailed frequency-domain measurements, structural analysis, and electronic design verification. This guide highlights the core capabilities and key differences between the four instruments in the lineup.

Frequency Range: Up to 102.4 kHz
Typical Dynamic Range: 90 dB
A/D Conversion: 16-bit
Channel Configurations: 1 or 2 channels

Models in this series

Model	Type	Averaging Types	Dimensions (W×H×D)	Display
SR785	*misc	Linear, Exponential, Equal Confidence	432 × 210 × 565	7-inch monochrome CRT, 640 × 480 pixels
SR780	*misc	RMS, Vector, Peak Hold	432 × 210 × 565 mm (17" × 8.25" × 22.25")	7-inch monochrome CRT (640 × 480 resolution)
SR760	*misc	Linear, Exponential, Peak Hold	432 mm × 159 mm × 470 mm	7-inch monochrome CRT (400H x 250V graphics)
SR770	*misc	Linear, Exponential	432 mm × 159 mm × 470 mm	7-inch monochrome CRT raster display

Single-Channel Entry: SR760 and SR770

The Stanford Research Systems SR760 and Stanford Research Systems SR770 are dedicated single-channel FFT analyzers covering a frequency range from 476 µHz to 100 kHz. Both models offer a 100 kHz real-time bandwidth and a fixed resolution of 400 lines (FFT bins).

While they share physical dimensions (432 mm x 159 mm x 470 mm), a weight of 16.3 kg, and a 60 W power requirement, they are distinguished by their signal generation capabilities. The Stanford Research Systems SR770 features an integrated synthesized source, making it suitable for active stimulus-response testing. The Stanford Research Systems SR760 is a passive spectrum analyzer, utilizing single-ended or differential input configurations with a 1 MΩ, 15 pF input impedance.

Dual-Channel Performance: SR780 and SR785

For applications requiring two-channel correlation, transfer functions, or broader real-time processing, the Stanford Research Systems SR780 and Stanford Research Systems SR785 provide a significant step up. Both support frequencies up to 102.4 kHz on both channels simultaneously and offer adjustable frequency resolution (100, 200, 400, or 800 lines).

Stanford Research Systems SR780: Offers a frequency range from 488 μHz to 102.4 kHz, 8 MSamples of standard memory (expandable to 32 MSamples), and a built-in 3.5-inch MS-DOS compatible floppy drive.
Stanford Research Systems SR785: Shares the same 102.4 kHz real-time bandwidth on both channels but introduces specialized measurement modes as standard. These include Octave Analysis Mode (conforming to ANSI S1.11-1983 Class 3), Swept-Sine Mode, Order Tracking Mode, and Correlation Mode, making it tailored for acoustics, vibration, and rotating machinery diagnostics.

Physical Form Factor and Interfaces

The physical characteristics scale with the complexity of the instruments. The single-channel models are more compact at 159 mm height and 16.3 kg, whereas the two-channel models require a larger chassis (210 mm height) and weigh 25.4 kg.

All instruments in the series feature 7-inch monochrome CRTs and offer standard remote interfaces including GPIB (IEEE-488) and RS-232 serial ports, alongside parallel printer connections to output measurement data directly to hardcopy.

Frequently asked questions

Which models in the SR700 series support two-channel measurements?: The Stanford Research Systems SR780 and Stanford Research Systems SR785 are two-channel dynamic signal analyzers, while the Stanford Research Systems SR760 and Stanford Research Systems SR770 are single-channel analyzers.
What is the primary difference between the SR760 and the SR770?: The Stanford Research Systems SR770 includes an integrated synthesized source for active signal stimulation, whereas the Stanford Research Systems SR760 is a passive spectrum analyzer without an internal source.
Can the memory of the SR780 be upgraded?: Yes, the Stanford Research Systems SR780 comes with a standard memory size of 8 MSamples, which can be expanded to 32 MSamples using Option 01.