HP 8444A - Instruments Covered by Manual

General Information
protective earth contact. The protection
must not be negated by using an exten-
sion cord (power cable) without a pro-
tective grounding conductor.
Interruption of the protective (ground-
ing) conductor, inside or outside the
instrument, or disconnection of the pro-
tective earth terminal is likely to make
this instrument dangerous. Intentional
interruption of the earth ground is pro-
hibited.
Servicing this instrument often requires
that you work with the instrument’s pro-
tective covers removed and with ac power
connected. Be very careful; the energy at
many points in the instrument may, if
contacted, cause personal injury.
With the ac power cable connected, the
ac line voltage is present at the terminals
of the power line module and at the LINE
power switch. Be very careful. Bodily
eontact with this voltage can be fatal.
ICAUTIONS
BEFORE SWITCHING ON THIS IN-
STRUMENT, make sure instrument's ac
input is set to the voltage of the ac power
source,
BEFORE SWITCHING ON THIS IN-
STRUMENT, make sure that all devices
connected to the instrument are con-
nected to the protective earth ground.
BEFORE SWITCHING ON THIS IN-
STRUMENT, make sure the line power
(mains) plug is connected to a three-
conductor line power outlet that has a
protective (earth) ground. (Grounding
one conductor of a two-conductor out-
let is not sufficient.
BEFORE SWITCHING ON THIS IN-
STRUMENT, make sure the ac line fuse
is of the required current rating and type
(normal-blow, time-delay, etc.).
1-16. INSTRUMENTS COVERED BY MANUAL
1-17. Hewlett-Packard instruments carry a serial
number (see Figure 1-2) on the back panel. When
1-2
Model 8444A
the serial number prefix on the instrument serial
number plate of your instrument is the same as one
of the prefix numbers on the inside title page of
this manual, the manual applies directly to the
instrument. When the instrument serial number
prefix is not listed on the inside title page of initial
issue, manual change sheets and manual up-dating
information is provided. Later editions or revisions
to the manual will contain the required change
information in Section VII.
SERIAL NUMBER
PREFIX
SUFFIX :
Figure 1-2. Instrument Identification
1-18. DESCRIPTION
1-19. The Model 8444A Tracking Generator is
designed to complement both Model 8554B and
Model 8555A Spectrum Analyzer RF Sections.
The Tracking Generator covers the frequency range
of 500 kHz to 1250 MHz when used with the
8554B RF Section and from 10 MHz to 1.8 GHz
when used with the 8555A RF Section. The
Tracking Generator/Spectrum Analyzer functions
as a system to perform frequency response meas-
urements. Additionally, the system can be used as
a signal generator or sweeper to supply a test signal
to other devices. An auxilliary output is provided
for precision frequency measurements by an exter-
nal frequency counter.
1-20. The Tracking Generator converts the first
and third local oscillator (LO) signals from the
Spectrum Analyzer RF Section, to a signal that
tracks the frequency tuning of the RF Section. With
the Spectrum Analyzer operating in ZERO SCAN
WIDTH, the Tracking Generator is a CW signal
generator, tuned to the frequency of the analyzer.
In FULL or PER DIVISION SCAN WIDTH the
Tracking Generator functions as a sweep oscillator
which tracks the analyzer tuning. Additionally, a