Amber 5500 - Page 18

Programmable
Audio
Measurement
System
Section 2
If an
invalid
frequency
why
is
attempted,
an
error will
be
displayed.
Examples
of errors
would be
requesting
a
frequency
outside
the
generator
range (e.g.,
1
MHz),
keying
in too
many
data
digits
(more
than
5)
or an
im-
proper
terminator
(Volts,
for
example).
A
special
method
of
frequency entry may
be
useful in
certain
circumstances.
If the
5500 is
reading
the
frequency
of
an extemal
source
(not
the
5500
internal
oscillator)
and it is
desired
to
set the
internal
oscillator to that
frequency,
the
first
inclination
would be to
key
in the
digits
of that
measured
frequency.
However,
a
simpler
way
exists. The
“*”
key
uses the
currently
measured value
as DATA.
So,
to
set the
internal
oscillator
to the
measured
extemal
frequency, just
push
the
FREQ
prefix
key
followed
by
the
*
(no
ter-
minator
is
required).
The
oscillator should
now
be
programmed
to the
frequency
of this
extemal
source.
2.2.2
IMD
FREQUENCY
(requires option
002
IMD)
The
FREQUENCY
prefix
key
in
the IMD
mode
sets
the HF
component
of
the
SMPTE/DIN
signal
or the
mean
frequency
of
the
CCIF
signal.
The
lower
limit of
the
analyzer
is 2
kHz. If a
lower
frequency
is
entered in
the IMD
mode,
the
resulting
meas-
urement
will be
non-valid.
The LP
component
of the
SMPTE/DIN
signal
or
offset
frequency
in
the CCIF
mode is
set
using
the
IMD LOW
FREQUENCY
prefix
key.
Eight
frequencies
are
available:
40, 50,
60,
80, 100,
125,
250
or
500
Hz. If a
number
other
than these
is
entered,
the
available
Amber
model
5500
Owner’s
Manual Version
07
frequency
closest to the
entered value
will be
automatically
selected.
Note
that when the
SMPTE/DIN
IMD func-
tion
is
selected,
if
the HF is below
2
kHz,
it is
automatically
set to
7 kHz. The
LP is set to
the
last used value.
The user
may
then over-
ride these values
with
additional numeric
entries. If another
function is
selected and
IMD
SMPTE/DIN
again selected,
the
pre-
viously
used
frequencies
will
be used
(unless
the
HF has been
set
to
below 2
kHz while
another
function was
selected).
On first
power-up,
the LF
oscillator
is set to
its default
value of
60 Hz.
Therefore,
the
first
time
the IMD
function is
selected
after default
state
power-up,
60
Hz will
be used.
If the LF
oscillator is
manually
changed
to
a
different
frequency,
it
will
remain at this
new
manually
entered
frequency
until either
again
manual-
ly
changed
or
until the
instrument is
powered
down.
The
offset
frequency
in the
CCIF
mode is one
half the
difference
frequency.
For
example,
if
a
high
frequency/mean
frequency
of
10
kHz
and a low
frequency/offset
frequency
of
60
Hz
is
selected,
then the
following
outputs
will
be
observed:
SMPTE mode:
HF:
10kHz
LF:
60Hz
CCIF
mode:
F1:
10060Hz
F2:
940 Hz
2-16
F