Atec Genrad-1390B - Manual (Page 2)

SPECIFICA liONS
Frequency Range: 5 Hz to 5 MHz.
Output: VOLTAGE: Max open-circuit output is at least 3 V for
20-kHz range, 2 V for 500-kHz range, and 1 V for 5-MHz range.
IMPEDANCE: Source impedance for max output is approx
900 n. Output is taken from a 2500-n potentiometer. Source
impedance for attenuated output is 200 n. One output ter­
minal is grounded.
Spectrum: See spectrum-level curves and following table.
Note: Spectrum level is shown with constant-Hz-bandwidth
analysis, "white" noise being ideally flat. (Pink noise would
slope down at 10 dB per decade.)
Range
20 kHz
500 kHz
5 MHz
Typical Spectrum Level
(with I-V rms output)
5 mV for I-Hz band
1.2 mV for I-Hz band
0.6 mV for 1 Hz band
Spectrum Level Uniformity·
within ±1 dB, 20 Hz to 20 kHz
within ±3 dB, 20 Hz to 500 kHz
within ±3 dB, 20 Hz to 500 kHz
within
±8 dB, 500 kHz to 5 MHz
•
Noise energy also beyond these limits. Level is down 3 dB at 5 Hz.
1kHz 10
FREQUENCY
'00
Typica I spectrum-level characteristics.
IMHz 10
131'0-)
Waveform: Noise source has good normal, or Gaussian, dis­
tribution of amplitudes for ranges of the frequency spectrum
that are narrow compared with the band selected. Over wide
ranges the distribution is less symmetrical because of dis­
symmetry introduced by the gas tube. Some clipping occurs
on the 500-kHz and 5-MHz ranges.
Voltmeter: Rectifier-type averaging meter measures output.
It is calibrated to read rms value of noise.
Attenuator: Multiplying factors of 1.0, 0.1, 0.01, 0.001, and
0.0001. Accurate to ±3% to 100 kHz, within ::!::10% to 5 MHz.
Available: Rack-adaptQr set (19x7 in.); 1390-P2 PINK-NOISE
FILTER.
Power: 1 0 5 to 125 or 210 to 250 V, 50 to 400 Hz, 5 0 W.
Mechanical: Convertible bench cabinet. DIMENSIONS (wx
hxd): Bench, 12.75x7.5x9.75 in. (324x191x248 mm).
WEIGHT: 12 Ib {5.5 kg) net, 16 Ib (7.5 kg) shipping.
Description
1390-8 Random-Noise Generator
115-V Model
230-V Model
Rack Adaptor Set (7 in.)
Catalog
Number
1390-9702
1390-9703
0480-9842
(A) Output (white noise) of the 1390-B Random-Noise Generator and
(B) output (pink noise) after filtering by the 1390-P2 Pink-Noise Filter, as measured by a one-third-octave band analyzer.
1390-P2 Pink-Noise Filter
Frequency Response: Sloping
-
3 dB per octave from 20 Hz to
20 kHz, -6 dB per octave above 20 kHz. Output voltage is
approx
-5 dB with respect to the input voltage at 20 Hz and
-35 dB at 20 kHz. It lies within 1 dB of the straight line con­
necting these two points on a graph of output in decibels vs log
frequency.
Over-all Output Level: When the filter is used with the random­
noise generator set for the 20-kHz range, the output voltage of
the filter is approx 30 dB below its input, and the voltage level
in each one-third-octave band is approx 17 dB below that.
Thus, when the output meter of the indicates 3 V,
the output of the filter is approx 0.1 V, and the level in each
one-third-octave band is approx
15 mY.
Input Impedance: The filter should be driven from a source
whose impedance is 1 kn or less. Input impedance is variable
from 6.5 kn + load resistance at zero frequency to 6.7 kn at
high frequencies.
Output Impedance: The filter should not be operated into a
load of less than 20 kn. Internal output impedance is variable
from
6.5 kn + source resistance at low frequencies to approx
200 n at high frequencies.
Max Input Voltage: 15 V rms.
Terminals: Input terminals are recessed banana pins on 3M-in.
spacing at rear of unit. Output terminals are jack-top binding
posts with 3M-in. spacing.
Mechanical: Plug-in unit housing. DIMENSIONS (wxhxd): l.38x
5x2.87 in. (35x127x73 mm). WEIGHT: 6 oz (0.2 kg) net,
4 Ib (l.9 kg) shipping.
Description
1390-P2 Pink-Noise Filter
•
Catalog
Number
1390-9602