Amber 5500 - Page 19

Amber
model
5500
Owner’s Manual
Version
07
Programmable
Audio
Measurement
System
Section 2
2.2.3
NARROW
BAND
FREQUENCY
One
of the
four meter
functions is
Narrow
Band Level. This
mode inserts
a band
pass,
low
pass
or
high pass
filter in
the
measure-
ment
path.
The center
frequency
of
the band
pass
or
the
comer
frequency
of the
high
or
low
pass
can be entered
by setting
the
gen-
erator to
the desired
frequency.
The
filter will
automatically
be set to
the same
frequency
as the
internal
generator.
It
is
also
possible
to
have
the filter
automatically
track the fre-
quency
of
the INPUT
signal
(if
the INPUT is
-30
dBm/30
mV or
greater)
by
setting
SPE-
CIAL
FUNCTION
28.2.
SPECIAL
FUNC-
TION
28.0
returns the
filter to
the
manual
mode
(see
Section
2.1.4).
..
2.2.4
GENERATOR
AMPLITUDE
(requires option
001
High
Level
Balanced
Output)
The
generator
output
amplitude
is a
funch'on
of several
factors:
a)
Requested
amplitude
as
specified
by
a
keyboard
entry
(or
GPIB
command)
b)
Specified
extemal load
impedance
(also
keyboard
or
GPIB)
c)
Actual
extemal load
impedance
d)
Generator source
impedance (50,
150
or
600
ohms)
e)
Units
used:
dBm,
dBV or
Volts
All
of the above
factors
will
have
an effect
on
the
signal
level
delivered
to the
load. Insuffi-
cient
attention
to this
detail
can lead
to un-
anticipated
errors. For
example,
if the
user
specifies
a
load
impedance
of
600 ohms
but
the
actual
load is
say,
592
ohms,
the
signal
will be
low
by
about 1%
with a
generator
source
impedance
of
600
ohms or
about
0.1% with a
50
ohm
source.
Section
2.2.6
following
describes how
to
set
the
specified
external
load
impedance.
The
values
entered will
be
used for
all
output
amplitudes.
The
default
conditions are
in-
finity (open circuit)
in the
Volts
or dBV
mode
and
600
ohms
in the
dBm
mode.
To
select a
generator
output
level
push
the
AMPLITUDE
prefix
key
followed
by
one to
five
data
entry keys
followed
by
a
units ter-
minator
key.
The
requested
level will
then be
presented
to
the
user
defined
load
(assuming
the
specified
load
and
the
actual
load
are
identical).
The
output
range,
in the
balanced
mode,
into
an
infinite
load
(open circuit)
is
33 V rms
maximum to
below
300
”V
rms
(+30
dBV to
-70
dBV).
The
output
range,
in
the
balanced
mode,
into
an
extemal
600 ohm
load
from a
150 ohm
source
is
+30 dBm to
-70 dBm.
Maximum
signal
levels in
the
unbalanced
mode
are
approximately
one
half of
the
balanced
levels.
Lower
signal
levels
can be
requested
and
achieved
but with
progres-
sively
degraded
resolution and
signal-to-
noise
ratio.
The
normal
amplitude
resolution
is
better
than
approximately
0.03 dB
or
0.3%
(i.e.
3
mV
at 1
V).
2-17