HP 8901B

General Information Model 8901B
Chassis Slide-Mount Kit.
This kit is extremely useful when the Modulation Analyzer is rack
mounted. Access to internal circuits and components
or the rear panel is possible without removing
the instrument from the rack. Order HP part number
1494-0017 for 432 mm (17 in.) fixed slides. (To
order adapters for non-HP rack enclosures, use HP
part number 1494-0023.)
Chassis-Tilt, Slide-Mount Kit. This kit is the same as the Chassis Slide Mount Kit above except it
also allows the tilting of the instrument up or down 90". Order HP part number 1494-0025 for 432 mm
(17 in.) tilting slides. To order adapters for non-HP rack enclosures, use HP part number 1494-0023.
1-9. DESCRIPTION OF THE MODULATION ANALYZER
The HP Model 8901B Modulation Analyzer is a complete measurement system for accurately
characterizing signals in the
150 kHz to 1300 MHz frequency range. It combines the capabilities
of four separate instruments in its ability to measure RF power, carrier frequency, modulation and
the characteristics of the demodulated audio signal
(as well as those of external audio signals). This
flexibility allows you
to make those measurements most commonly needed to totally characterize
a signal.
The Modulation Analyzer can measure an RF signal's frequency, frequency drift, power level
(broadband, and off-channel), amplitude modulation (AM), frequency modulation (FM), phase
modulation (@M), and AM and FM noise components.
It recovers the modulating signal and can
measure the audio signal's frequency and distortion.
The Modulation Analyzer is fully automatic and all major measurements can be made by pushing a
single key. The Modulation Analyzer's large digital display shows measurement results with excellent
resolution and
is easy to read. All Modulation Analyzer operations can be controlled and all
measurement results can be transferred via the Hewlett-Packard Interface Bus (HP-IB). (HP-IB is
Hewlett-Packard's implementation of IEEE Standard 488 and ANSI Standard MC1.l.)
RF Power Measurements
The Modulation Analyzer delivers the accuracy and resolution of a high-performance power meter.
The HP
8901B, with the HP 11722A Sensor Module, measures power from +30 dBm to -20 dBm
at frequencies from
100 kHz to 2.6 GHz. (Refer to Table 1-1, Specifications, for specified frequencies
limits using other power sensors. The HP
890lB also accepts all HP 8480 series power sensors for
extended measurement capability.)
Input Power Protection. The Modulation Analyzer is equipped with input power protection to prevent
damage from the accidental application of excessive power.
(This is a common cause of damage in
equipment used
to measure transmitters.) The Modulation Analyzer is tested for inputs up to 2W.
Protection is provided by limiting diodes and an RF relay. When excessive power is applied, the relay
opens and protects sensitive components, and the Modulation Analyzer displays an error message. The
circuit automatically resets whenever
a key is depressed.
RF Power Calibration. RF Power Calibration is accomplished with the 50 MHz, 1 mW standard
available in every instrument. Also, the front-panel ZERO function enables you
to zero the sensor
module without removing it from the source-under-test. After the ZERO key
is pressed, the new zero
offsets are stored automatically.
RF Power Calibration Factors. RF Power Calibration Factors can be entered from the power sensor
into the Modulation Analyzer's non-volatile memory. The instrument automatically compensates for
the power sensor's efficiency and mismatch loss at each frequency.
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