CHARACTERISTICS
The Type 491
Spectrum Analyzer is a wide band,
general purpose portable spectrum analyzer with an RF
center frequency range from 10 MHz to 40 GHz. The ana-
lyzer displays signal amplitude as a function of frequency
played along the horizontal axis (dispersion) and signal
The following electrical characteristics apply at an ambient
amplitude on the vertical axis of a self-contained system.
temperature of 25 C (5C) after an initial warmup period
of approximately 20 minutes.
ELECTRICAL CHARACTERISTICS
Performance
Requirement
Supplemental Information
Characteristic
RF Center
10 MHz to 40 GHz--See Table 1-1
Frequency Range
I
CW Sensitivity
See Table 1-1
(S + N=2N)
Dial Accuracy
Within (2 MHz +1% of dial reading)
IF CENTER FREQ central at 000, FINE IF
I
CENTER FREQ control and FINE RF CENTER
FREQ controls centered.
Minimum CW
Sensitivity (S + N = 2N)
Band and
Supplemental
RF CENTER FREQUENCY
1 kHz
RESOLUTION
Scale
100 kHz RESOLUTION
Information
100 dBm
10-275 MHz
80 dBm
A-1
110 dBm
90 dBm
B-2
275-900 MHz
105 dBm
85 dBm
3
800-2000 MHz
1.5-4.0 GHz
110 dBm
90 dBm
C-4
50 Ω source impedance.
100 dBm
5
3.8-8.2 GHz
-80 dBm
75 dBm
6
8.0-2.4 Ghz
95 dBm
12.4-18.0 GHz
7
90 dBm
70 dBm
8
18.0 -26,5 GHz
-60 dBm
80 dBm
All voltages are RMS.
!
26.5-40.0 GHz
70 dBm
-50
dBm
DISPERSION/DIV
Accuracy
Setting
Remarks
--
3%
(0.3
MHz/Div)
10MHz
Over the 25 MHz of the IF Center FREQ control ex-
cept the 10 MHz/DIV position ( 10 MHz). The DIS-
3%
(0.15
MHz/Div)
5 MHz
PERSION CAL adjust can be reset to improve the ac-
2 MHz
5% (0.1 MHz/Div)
curacy at a specific IF CENTER FREQ control setting
1 MHz
7% (70 kHz/Div)
by using the front panel 1 MHz CAL MARKERS OUT as
a calibrated signal.
10% (50 kHz/Div)
.5 MHz
15% (30 kHz/Div)
Measured over the center 8 divisions of the graticule.
.2 MHz
1-1
