Marconi Instruments 2955 - Page 54

OPERATION
(J^
StLEC
1
key and
LEDs.
For
selecting
socket
(n)
for tones
simplex
operation.
In
duplex
mode,
selects
one-pon
or
two-port
operation.
(Q
RF
IN/OUT
N
socket.
For rones
simplex
or
one-port duplex
operation.
A tempera-
ture
sensor
detects
excessive
power
being applied.
Impedance
50
O.
(2)
GBN
OUTPUT
socket.
BNC
connector
supplying an
output
in the
range
20 Hz
to
20
kHz
for
single
tone
modulation
plus a fixed
1 kHz for
two-tone
modulation.
Impe-
dance
5
n.
Transmitter
test
The
tones
receiver
accepts up
to
12 successive
tones
including inter-tone
pauses.
Frequency
range
is
300
Hz
to 3.4
kHz.
duration
is 25 ms to
1.2
s and inter-tone
pauses
are up
to
800
ms.
To receive
a
programmed
cafiing
tone
sequence,
proceed
as follows:-
(1)
Select
TX
Q),
TRANSMITTER
TEST
is
written
on the
screen.
(2)
Connect
the
output
from
the
transmitter
to
the
N
connector
(JT).
(3)
Key
up
the
transmitter
and
ensure
t.hat the instrument is correctly tuned
to the
transmitter's
frequency.
(4)
Select
TONES
Q
with
the
transminer
on.
The TONES
STANDARD
MENU
is
displayed.
Tnis
enables
the
selection
of one
of
four tone frequency standards
or
of a
user-defined
standard
or
two-tone
operation.
(5)
If
a
return
to
the
TRANSMITTER
TEST display
is
.required,
press
the
MODE
(
3
)
w’hich
is
arrowed
by
RETURN.
Tone
frequency
standard
(6)
Select
the
required tone frequency
standard
(as
shown in
Table 3-1)
from
the
4
offered
on
the
displsv
usins
t.he
MODE kev which
is
arrowed
bv
the
frequency
standard,
e.g.
CCER.
(7)
TX
SEQUENTIAL
TONE
is
displayed.
(8)
Press
the
key
arrowed
by
RESET.
The
RE.ADY
prompt is
displayed.
3-30
46aai-622N
Apr.
88