Racal Instruments 1994 Service Manual page 73

Table
3.2
-
Rear
Panel Controls and Connectors
(Cont'd)
Reference
Item
Function/Description
©
'
10
MHz
STD.
OUTPUT
Connector
Output
for 10
MHz
internal reference
signal
©
EXT.
ARM
INPUT
Connector
Input for external arming/gating control
signal
©
EXT.
STD INPUT
Input for
external reference
frequency
standard. The
required frequency
is
10
MHz,
unless the reference
frequency
multiplier (Option
10)
is
installed. This
option permits acceptance
of
1
MHz,
2
MHz,
5
MHz
as well as 10
MHz
external reference
signals
©
LEVEL ADJUST
Adjustment
of the
trigger level for
the
external arming
input
OSC
ADJ
Adjustment
of the
internal reference
frequency standard
INPUT A
Connector
(Option
01)
Rear-panel
Input
A
©
INPUT
B
Connector
(Option
01)
Rear-panel
Input
B
INPUT C
Connector
(Option 01
for units
fitted
with Option
41)
Rear-panel
Input
C
TRIGGER LEVEL OUTPUTS
(A, B)
Outputs
for Inputs
A
and
B
trigger
levels.
Voltage range
at both
pins
is
±5.
IV, regardless of attenuation
IHi
GATE OUTPUT
Output
for
negative-going TTL-compat-
ible
signal
equivalent
to the gate
signal
3-17/3-18 Blank