Filter Assembly A4; Video Amplifier A5 - HP 5254C Operating And Service Manual

Model 5254C
Section VII
Table
7-1,
A5 Video Amplifier
Assembly
Make
the following
changes
in
parts
list
for
A5:
A5R32: change
to
R FXD
2400
OHM, HP
PART
NO. 0683-3925.
A5E1:
delete
CHANGE
2:
Figure 7-2
A
5
Video Amplifier Assembly:
Make
the
following changes:
A5R2: change
to:
R FXD
100K
Table 7-1
A5
Video Amplifier Assembly:
Make
the following
changes:
A5R2: change
to:
R FXD
100K,
HP PART
NO.
0683-1045.
MP4:
change
to
HP PART
NO.
MP5:
change
to
HP PART
NO.
MP6:
change
to
HP PART
NO.
MP7:
change
to
HP PART
NO.
MP8
:
change
to
HP PART
NO.
MP12:
change
to
HP PART
NO.
05254-2029
05254-0007
05254-0004
05254-0003
05254-0002
05254-0001
7-20.
MULTIPLIER AMPLIFIER
ASSEMBLY
Al.
7-21.
The
Multiplier
Amplifier
is
similar
to
that
used
in
the
5254B.
The main
difference
is
that
A1R17
is
not
used and
A1R16
is
changed
to
10K
ohms
(a
fac-
tory
selected
value, typical
value shown).
See Fig-
ure 7-5.
7-22.
HARMONIC
GENERATOR ASSEMBLY
A2
AND HARMONIC SELECTOR
CAVITY.
7-23.
The Harmonic Generator and
Harmonic
Selec-
tor
Cavity
are
the
same
as that in the
Model
5254B.
(See
Figure
7-5.
7-24.
MIXER ASSEMBLY
A3.
7-25.
The Mixer Assembly
is
the
same
as
that in
the
5254B.
(See
Figure 7-6.)
7-26.
FILTER
ASSEMBLY
A4.
7-27.
The
Filter
Assembly
is
the
same
as that in
the
5254B.
(See
Figure 7-6.)
7-28.
VIDEO AMPLIFIER
A5.
7-29.
The Video Amplifier
is
similar
to
that
used
in
the
5254B.
(See
Figure 7-6.)
However,
trigger cir-
cuit
A5Q13, A5Q14, and
A5Q15
has
been eliminated.
The
output signal
at
A5Q10
emitter
is
applied
to
A5Q11
base.
A5Q11
is
a buffer amplifier with a re-
sistive
divider output providing the output to
the
coun-
ter
and
the
external output.
There
is sufficient
isola-
tion in the
divider
network
to
prevent
the signal to the
counter
from
being affected
by termination
at
the ex-
ternal output.
7-30.
The signal for the
meter amplifier
is
taken
from A5Q10 emitter and applied to
A5Q12
base.
Meter
amplifier
A5Q12
is
a current amplifier driving
meter
rectifier
A5CR2. A5R39
and
A5C22
provide
damping
for the
meter.
A5C19
adjusts the
meter
amplifier
high
frequency gain
to
make
the level
meter read
at
red-green border
when
converter
output
is
more
than
the
minimum
100
mV
normally required at the
counter
input.
* Ferrite
bead
A5E1
was
added
to
A5Q12
emitter
to
suppress
oscillation
caused
when A5R32 was
changed
for
improved
A5Q12
operation.
7-3