Marconi Instruments 2955 - Page 27

OPERATION
MODE
keys.
These
are
used
to select transmitter
testing,
receiver
testing,
duplex
testing
or tones
testing.
.-Mso,
these are
used as soft keys to
select
programmed
functions
from
menus which
are
shown
alongside
on
the
screen.
0
BAR
CHART
key. When
this
is selected,
the
bottom
half of
the
screen
shows
veni-
cai
bar
chans.
Also, this
is used
as
a soft key
to
select a
programmed
function
from
menus which
are
shown
alongside
on the
screen.
0
STORE
key.
Stores
ail
front
panel settings except
those
of the
analogue
controls
such as intensity,
volume,
etc.
It
is
followed
by a
2-digit number
in
the
range
01
to
37 to
identify
the
stored setting.
Store
00
is
automatically allocated
to
the
instrument
setting
at
switch-off
or
loss of mains
or
battery
power.
(T)
RECALL
key. When
followed
by a 2-digit number;
recalls the front
panel
setting
previously
stored
using
0.
When
followed"
by
00,
restores
the
instrument
settings
to
those
set.
at the time
of switch-off
etc.
0
HOLD
DISPLAY
key.
Freezes
the
display including
the
oscilloscope
or
bar charts
(but
not the
trace).
.Ail the
front
panel
keys except
HOLD
DISPLAY
are inoperable.
When
the
key
is
pressed
again, the
hold
is
released. .Also,
this
is
used as a soft key to
select
a
programmed
function
from
menus
which are
shown alongside on the screen.
0
HELP
key.
Displays
the
HELP menu.
See under ‘HELP Key
Operation’.
0
POSITION
controls.
Used
to
vary
the trace position,
both
horizontally
and verti-
cally.
(0
SINGLE
SWEEP key.
Allows only
one sweep
of
the oscilloscope
trace to occur
after
a trigger
and
implements
the
storage
oscilloscope facility.
Resets
the sweep
if it is
pan
way
through.
0
REP
SWEEP
key.
Repetitively
sweeps
the oscilloscope
trace on auto
trigger.
Qj)
HORIZ
key.
Changes
the
oscilloscope
horizontal scale
time per
division.
0
VERT
keys,
fn
TX
mode,
these change the
oscilloscope
vertical
scale
in
modulation
units
per
division.
In RX
mode,
they change the
oscilloscope
vertical
scale
in
volts per
division.
(0
INTENSITY
control.
Varies
the
brightness of the display.
0
VOLUME
control.
Controls the output
of
the built-in
loudspeaker
which
is
used for
monitoring
and
for
alarms.
(0
SUPPLY
switch.
W'hen
it
is
switched to ON.
the instrument
enters
the RX
mode.
46381
-622N
Apr,
88
3-3