Amber 5500 - Output On;Off; Signal Sources

Amber model
5500
Owner’s Manual
Version
07
2.2.7
GROUND/FLOAT
The
shifted
mode
of the
CONFIGURATION
button allows the
output
to be
ground
refer-
enced or
floated. The normal
mode is
inter-
nal GND
reference. If the
output
is
ground
referenced via the
extemal
equipment being
measured,
the FLOAT mode
may
be
selected
to avoid
a
ground
loop.
The
output
must
have
a
ground
reference
from
one of the
several
possible
paths: output
GND
mode,
through
the device
under test
or via an ex-
ternal
ground
connection.
In the GND
mode,
the
center
tap
of
the
BALANCED
output
is
connected to
chassis
and the low side of
the
UNBALANCED out-
put
is
connected to
chassis. This
chassis con-
nection is via
a
voltage
dependent
resistor/capacitor
network
for
protection.
2.2.8 OUTPUT
ON/OFF
The
top push
button in the
OUTPUT
group
is the
output
ON/OFF
function. This
can
be
used for
signal-to-noise
ratio
measurements
or other
applications
requiring
a
quiet
ter-
mination.
When the
output
is
OFF,
the
source
impedance
remains the
same as
in the ON
mode.
2.2.9
B
OUTPUT
(if
option
007
provided)
The
shifted mode of
the
ON/OFF
key
selects
the
optional
dual
output.
If
the second
(B)
output
module
is
provided,
the
output may
be set
to
feed
A
only,
B
only,
A
and B in
phase
or
A and B out
of
phase.
Both
outputs
have
the same
level,
source
impedance
and con-
Programmable
Audio
Measurement
System
Section 2
figuration.
The two
outputs
are
resistively
isolated
but
come
from a
Common
power
amplifier.
See Tables
1 and 2
for
combined
output
load
limitations.
2.2.10
EXTERNAL INPUT
An
extemal
input
is
provided
on the
rear
panel
of the
5500
to allow
the
user to
supply
an
extemal
special
source
signal
(such
as a
function
generator,
square wave,
pink
noise,
etc.).
To
select the
external
source,
key
in
14.4
SPCL. To
select the
internal oscillator
(default
condition),
key
in
14.1
SPCL. The
external source
must have
a
nominal
signal
level
of
+10
dBV/3.16V
and
will
benefit
from
output
power amplifier
transformer
isolation,
output attenuator,
output
con-
figuration
and
amplitude
setting provision.
Every
time
a new
FUNCTION is
selected,
the
default
signal
source is
again
selected. For
example,
if the
instrument is
in the
WIDE
BAND
LEVEL mode
and
Special
Function
14.4 is
selected,
the
external
signal
source
will
be
on. If the
THD
function is
now
selected,
the
internal
source
(that
is,
the
default source
or
14.1
SPCL)
will be
selected
at the same
time that
THD is
entered. To use
the
external
source in
this new
TI-ID
mode,
again
key
in
14.4
SPCL.
2.2.11
SIGNAL
SOURCES
Special
Function 14
has a
more
general
ap-
plication.
It
may
also
be
used to
select
any
of
the
optional
special
signal
sources
that
may
be
provided
on the
5500. Table
2.2.11 lists
the
signal sources,
special
function
code and
conditions. As
with the
external
input
2—23