HP 5254C - SECTION VII MODEL 5254 A AND 5254 B; INTRODUCTION TO VARIANTS; MODEL 5254 A DESCRIPTION; MODEL 5254 A SPECIFICATIONS

Model
5254C
Section
VII
SECTION
VII
MODEL
5254A
AND
5254B
7-1.
INTRODUCTION
7
2
The
HP
Model
5254A
is
basically
the
same
as
the
HP
5254B.
The
HP
5254B
is
an
improved
version
of
the
HP
5254A.
The
differences
are
in
the
frequen-
cies
measured,
and
circuit
changes
in A1
Multiplier
Assembly
and
A5
Video
Amplifier
Assembly.
Also,
MP1
Cavity
Assembly
has
a
slight
gearing
change.
The
video
external
output
appears
at
plug
-in
connec-
tor
P6(46)
and
is
supplied
to
AUX
A
jack
on
counter
rear
panel.
7-3.
To
adapt
this
manual
to
Model
5254B
proceed
as
follows:
a.
Change
all
5254C
model
number
references
to
5254B.
b.
Change
all
low
limit
operating
frequency
refer-
ences
to
200
MHz.
c.
Page
6-7,
Table
6-1:
Change
MP2
to
05254-
2063.
d.
Page
6-6,
Table
6-1:
Change
05254-6026
to
05254-6019.
e.
Page
6-6,
Table
6-1:
Change
05254-6027
to
05254-6023.
f
p
a
ge
6-7,
Table
6-1:
Change
MP4
to
05254-
2056.
g.
Page
6-8,
Table
6-1:
Change
05254-2074
to
05254-4003
and
delete
(COATED).
h.
Page
6-7,
Table
6-1:
Delete
from
MP4
05254-
2073
description
"OPTION
A85".
Delete
MP16
05254-2076.
7-4
The
balance
of
this
section
discusses
the
differ-
ences
in
the
HP
5254A
specifications,
operating
pro-
cedure
adjustments,
troubleshooting,
and
circuits.
Changes
in
parts
list,
schematic
diagrams
and
com-
ponent
location
are
also
given.
These
apply
for
HP
5254
A’ s
with
serial
number
prefix
51
4-.
7-5 For
older
HP
5254A
converters
with
serial
pre-
fix
number
429-,
or
415-,
Paragraph
7-18
outlines
the
changes
required
in
this
section.
7-6.
DESCRIPTION
7-7.
The
HP
5254A
converts
a
Hewlett-Packard
Electronic
counter
into
a
direct
reading
counter
from
3
to
3.
0
GHz
with
an
input
voltage
range
of
50
mV
to
IV
rras.
The
stability
and
accuracy
of
the
basic
coun-
ter
is
retained
by
multiplying
a
10-MHz
signal,
derived
from
the
1-MHz
internal
time
base
of
the
counter,
to
a
selectable
harmonic
frequency
between
.
3
to
3. 0
GHz.
This
known
harmonic
of
50
MHz
is
then
he
eio
dyned
with
the
input
signal.
If
resulting
difference
frequency
is
between
1
MHz
and
53
MHz
(bandwidth
of
A5
Video
Amplifier),
it
is
counted
and
displayed
by
the
counter.
The
frequency
of
the
JNPUl
'
sjgjaj
1S
then
indicated
by
the
combination
of
the
MIXING
FREQUENCY
control
on
the
front
panel
of
the
plug-in,
and
the
counter
display
in
megahertz.
A
front
panel
Level
Meter,
by
monitoring
the
difference
frequency
output
to
the
counter,
aids
in
selecting
the
desired
MIXING
FREQUENCY
and
also
in
determining
ii
input
signal
amplitude
is
adequate
for
accurate
frequency
measurement.
7-8.
SPECIFICATIONS
7-9.
Table
7-1
contains
all
technical
specifications
for
the
HP
5254A
when
operating
in
an
HP
counter.
Table
7-1.
Specifications
for
5254A
RANGE:
.
„
.
As
a
converter
for
an
HP
Electronic
Counter,
300
to
3000
MHz.
ACCURACY:
Retains
accuracy
of
an
HP
Electronic
Counter.
INPUT
SIGNAL
LEVEL:
50
mV
rms
(-13
dbm
in
50
ohms)
to
IV
rms
(+13
dBm
in
50
ohms).
INPUT
OVERLOAD:
Input
power
in
excess
of
100
mW
(+20
dBm
or
2.
2V
rms)
may
damage
the
converter.
INPUT
IMPEDANCE:
Approximately
50
ohms.
INPUT
CONNECTOR:
Type
N
female
LEVEL
INDICATOR:
Meter
aids
frequency
selection;
indicates
output
voltage
level
to
counter.
REGISTRATION:
Counter
display
in
MHz
is
added
to
the
converter
dial
reading.
WEIGHT:
.
„
.
Net,
5
lbs
(2,
5
kg);
shipping
7
lb
(3,
2
kg).
7-10.
OPERATING
PROCEDURE
7-11.
Figure
7-1 shows
the
Frequency
Measurement
Procedure.
Amplitude
specifications
for
the
HP
52 54 A
and
HP
5254B
are
the
same.
7-12.
ADJUSTMENTS
7-13
The
circuit
adjustments
described
in
Para-
graphs
5-36
through
5-43 are
the
same
for
both
the
5254A
and
B.
However,
Meter
High
Frequency
ad-
justment
capacitor
A5C19
in
the
HP
5254B
is
num-
bered
A5C21
in
the
HP
5254A
with
A5R17
is
not
used.
7-1