Stanford Research Systems SR770 Data Sheet

· DC to 100 kHz bandwidth

· 90 dB dynamic range

· Low-distortion synthesized source
(SR770)

· Harmonic, band & sideband analysis

· 100 kHz real-time bandwidth

· Hardcopy output to printers and
plotters

· 3.5" DOS compatible disk drive

· GPIB and RS-232 interfaces

· SR760 ... $4950

(U.S. list)

· SR770 ... $6500 (U.S. list)

Stanford Research Systems phone: [phone]

www.thinkSRS.com

The SR760 and SR770 are single-channel, 100 kHz FFT
spectrum analyzers with a dynamic range of 90 dB and a
real-time bandwidth of 100 kHz. The SR770 additionally
includes a low-distortion, synthesized source allowing you to
measure the transfer functions of electronic and mechanical
systems. The speed and dynamic range of these instruments,
coupled with their flexibility and many analysis modes, makes
them the ideal choice for a variety of applications including
acoustics, vibration, noise measurement, and general
electronic use.

High Dynamic Range

The SR760 and SR770 have a dynamic range of 90 dB. This
means that for a full-scale input signal the instruments have no
spurious responses larger than −90 dBc (1 part in 30,000).
Even signals as small as −114 dBc (1 part in 500,000) may be
observed by using averaging. The low front-end noise and low
harmonic distortion allow you to see signals that are buried in
the noise of other analyzers.

Powerful Processing

The SR760 and SR770 use a pair of high-speed, 24-bit digital
signal processors (DSPs) to filter, heterodyne and transform
sampled data from its 16-bit analog-to-digital converter. These
DSPs can perform 25 million, 24-bit multiplications and
additions each second. This enormous computing capability
allows the analyzers to operate at a real-time bandwidth of
100 kHz. In other words, the SR760 and SR770 process the

SR760/SR770 FFT Spectrum Analyzers

FFT Spectrum Analyzers

SR760 and SR770  100 kHz, single-channel FFT spectrum analyzers

www.thinkSRS.com

Available from:

Thurlby Thandar Instruments Ltd. Glebe Road, Huntingdon, Cambs.
PE29 7DR U.K. Tel: [phone] e-mail:[e-mail]

Web: www.tti-test.com or www.tti.co.uk

input signal with no dead time. Your measurements will be
done in as little as a tenth of the time of other analyzers, which
typically have real-time bandwidths of about 10 kHz.

Easy To Use

The SR760 and SR770 are easy to use. The simple, menu­oriented interface logically groups related instrument
functions. Context-sensitive help is available for all keys and
menus, and entire instrument setups can be saved to disk and
recalled with a single keystroke.

Spectrum Measurements

The spectrum, power spectral density and input time record
can be displayed in a variety of convenient linear and
logarithmic units including Vp, Vrms, dBVp, dBVrms or user­defined Engineering Units (EUs). The magnitude, phase, and
real and imaginary parts of complex signals can all be

displayed. Several window functions including Hanning,
Flat-Top, Uniform and Blackman-Harris can be chosen to
optimize in-band amplitude accuracy or minimize out-of-band
sidelobes.

Triggering and Averaging

Flexible triggering and averaging modes let you see signals as
low as 114 dB below full scale. RMS averaging provides an
excellent estimate of the true signal and noise levels in the
input signal, while vector averaging can be used with a
triggered input signal to actually reduce the measured noise
level. Both rms and vector averaging can be performed
exponentially, where the analyzer computes a running average
(weighting new data more heavily than older data), or linearly,
where the analyzer computes an equally weighted average of
a specified number of records. Triggering can be used to
capture transient events or to preserve spectral phase
information. Both internal and external triggering are
available with adjustable pre-trigger and post-trigger delays.

Octave Measurements

The SR760 and SR770 also compute both the 15 and 30 band
1/3 octave spectra, commonly used in acoustics and noise

measurement applications. A-weighting compensation is
available for octave measurements. Amplitudes are computed
for band −2 (630 mHz) through band 49 (80 kHz).

Synthesized Source

The SR770 includes a low-distortion (−80 dB), synthesized
source which can be used to make frequency response
measurements. It generates single frequency sine waves, two­tone signals for intermodulation distortion (IMD) testing, pink
and white noise for audio and electronic applications, and
frequency chirps for transfer function analysis. This direct
digital synthesis (DDS) source provides an output level from
100 µV to 1 V, and delivers up to 50 mA of current.

Frequency Response Measurements

With its low-distortion DDS source, the SR770 is capable of
performing accurate frequency response measurements. The

SR760 and SR770 FFT Spectrum Analyzers

Stanford Research Systems phone: [phone]

www.thinkSRS.com

Spectrum analysis

Octave analysis

Transfer function (magnitude and phase)