7
Applications
The HP 8901A Modulation Ana-
lyzer is a useful tool for analyzing
many types of signals. Often it
can provide needed information
that has been difficult to obtain
such as incidental FM or residual
FM. It can replace large, complex
test systems, and speed and sim-
plify measurements. The modula-
tion analyzer is superbly capable
of measuring transmitters used in
mobile communications. This single
instrument can be used in making
most of the measurements made on
transmitters.
The modulation analyzer can be
equally useful for other types of
transmitters. For avionics appli-
cations it can be very useful in
measuring navigation signals. In
testing ILS transmitters the ana-
lyzer can be used to very accu-
rately measure depth of
modulation. For broadcast AM and
FM it can be used to measure AM
depth or FM deviation, and it can
accurately recover the modula-
tion for making measurements
such as stereo separation.
With its accuracy the modulation
analyzer makes an excellent addi-
tion to a metrology laboratory. An
example of its usefulness is in
calibrating signal generators.
The modulation analyzer’s capa-
bilities exceed those required to
verify many signal generator
specifications. Besides improving
the accuracy of these measure-
ments it greatly reduces the time
involved in making measure-
ments. Also, the optional calibra-
tors provide a new level of
modulation standard accuracy
and help ensure accurate mea-
surements. They also enhance
the calibration of the modulation
analyzer itself .
Because the modulation analyzer
is useful for characterizing all
types of signals in general, it is
very useful in research and devel-
opment laboratories. It can be
used for characterizing VCO’s,
measuring residual noise on
crystal oscillators, measuring
incidental modulation, measuring
frequency on low level signals,
etc. When used with a signal
source it can be used to charac-
terize RF and IF designs, evaluate
modulators, and test individual
IC’s or modules.
Programmability
The HP 8901A Modulation Ana-
lyzer is completely programmable
via the Hewlett-Packard Interface
Bus (HP-IB). This, coupled with
the ability of the modulation ana-
lyzer to make several measure-
ments, the speed with which these
measurements can be made, and
the flexibility of the special func-
tions, makes the modulation ana-
lyzer ideal for systems
applications. In many instances
it can reduce the number of in-
struments in a system, speed
measurements, reduce complex-
ity, and improve accuracy.
When the analyzer is in remote,
the front panel annunciators make
it very easy to determine what
state the analyzer is in.