Marconi Instruments 2955 - Page 35

OPERATION
MODULATION
METER
Fig. 3-5
Modulation
meter
controls
and connectors
Q
TX
key.
Connects
the
moduiation
meter
to
RF
IN/OUT
socket
(7)
or
©
and
connects
the
.AP
generator
to
the
AF
GEN
OUTPUT
socket
(^.
Writes
on
the
screen
information
concerning
instrument
seciinss.
(1)
AF
GEN
key.
Enables
the
in
rnal
AF
generator
to supply a
modulating signal
to
socket
(Q
.
(T)
MOD
FM
key
and
LED.
When
the
key
is
pressed, the
LED
lights
to
show that-the
FWI
route
to
the
demodulator
has
been
selected.
(T)
MOD
AM
key
and
LED. When
the
key is
pressed,
the
LED
lights
to
show
that the
AM
route
to
the
demodulator
has
been selected.
@
MOD
d>M
key
and
LED.
When
the
key
is
pressed,
the LED lights to
show
that the
0M
route
(FM
route
with
de-emphasis)
has
been
selected
to
the demodulator.
0
SELECT
key
and
LEDs.
For
selecting RE
IN/OUT BNC or N
socket
©
or
0.
LED
lights
above
the
socket
selected.
0
RF
IN/OUT
BNC
socket.
For
the telescopic
aerial
option.
Autom.atically protected
against
excessive
power.
(0
RF
IN/OUT
N
socket.
For
high
level
inputs.
A
temperature
sensor
detects exces-
sive power
being
applied.
Impedance
50
Cl.
46881
-622N
Apr.
88
3-11