GE 4PE21A1 Instructions Manual page 40

CHANNEL AMPLIFIER EBI-36141
Control
Symbol
Function
FOCUS CURRENT
Rltj3
Adjusts the camera focus coil
current from
20
milliamperes
to 120 milliamperes.
BLANKING ADJUST
POS R28 Adjusts proper blanking level
when positive video
is used.
BLANKING ADJUST NEG
R29
Adjusts proper blanking level
when negative video
is used.
CABLE
COMP
S2
Compensates both phase and
frequency response for
various camera cable lengths.
APER
CORR
GAMMA ON
-01111
PRE -OPERATIONAL SETUP PROCEDURE
S1
Off
or two
different ratios
of
high -frequency boost.
S3
Off
or a
2.5:1 correction
slope factor.
OPERATION
Prior
to
putting
the Channel Amplifier and its associated equipments
into operational use, the
procedures
as
set
forth below
should be performed
to ensure proper operation of the Channel Amplifier during actual
use.
1.
Apply power
to the
Amplifier
and
measure
the B+ (280 v
d -c) at
J17-2 and bias
voltage
(-lÓ5
to
-110 v
d -c)
at
J23.
2.
Measure
the H BUFFERED DRIVE output voltage
at J9 (1.8
±
0.2
volt
peak -to -peak into 51 ohms
impedance) and the V
BUFFERED DRIVE output voltage
at J10 (3.0
±
0.2
volt peak
-to
-peak into
51 ohms impedance).
3.
With the camera
B+
turned
on,
measure
the
FOCUS CURRENT
at J21.
The current
measurement
is
taken across
a
100 -ohm, 1% resistor. Using
a
20,000 -ohm per volt voltmeter,
a
reading
of
7.5 volts d -c will represent
75
milliamps of focus coil current. Set the current required by adjusting
the FOCUS CURRENT control,
R1143.
A thin blade screwdriver or tuning wand
is necessary
to
make this adjustment.
14.
Obtain
a
normal video picture
on the
control monitor from the
camera chain by observing
the VIDEO input
at
J18, and the camera view-
finder. The video signal level
at J18
must be
0.2 to 2.0
volts peak
-to
-
peak.
5