HP 8340b User Manual

10.
Using
a
frequency
synthesizer,
inject a
250
MHz
CW
signal,
at
0
dBm,
into
the
cable
marked
A36J2.
11.
Connect
a
spectrum
analyzer
to
A38J1
and
verify
a
CW
output
between
84
and
89.85
MHz,
at
approximately
—10
dBm.
If
this
output
is
not
correct,
repair or
replace
the
A38
assembly.
12. Disconnect
the
cables from
the
frequency
synthesizer
and
the
spectrum
analyzer.
Turn
the
instru¬
ment's
power
switch
to STANDBY.
13.
Reinstall the
A36
PLL1
VCO
and related
coax cables.
Leave
the
power
switch
in
the
STANDBY
position
and
proceed
directly
to
step
14.
Verifying
the
Operation
of the
A37
PLL1
Divider
14.
Place
the A37
PLL1
divider
on an
extender board.
This
closes
the
PLL1
phase
lock
loop.
Turn
the
instrument's
power
switch
on.
15.
Connect
a
spectrum analyzer
to
the
cable
marked
A37J1
and
verify
a CW
frequency
of
10
MHz
at
0
dBm.
If
this
signal
Is
not
correct,
troubleshoot
the
reference
loop.
Refer
to
the
reference
loop
—
M/N
loop
section.
18.
Disconnect
the
spectrum
analyzer
and
reconnect
the
cable
marked
A37J1
to
A37J1.
VERIFY
THAT THE PHASE/FREQUENCY DETECTOR WILL CAUSE THE VCO TO
REACH
OPERATIONAL
LIMITS.
17.
Connect an
oscilloscope to
the
A37
PLL1
divider
as
follows:
Connect
Channel
A
to
A37TP11
Connect
Channel
B
to
A37TP12
Set
the
Horizontal
sweep
time to
2
ns/div
18.
Using
a
frequency synthesizer,
inject
a 34
MHz,
-10
dBm
signal
into
the
cable
marked
A38J1,
19.
Monitor the
waveforms
on
the
oscilloscope.
Note
that
the
waveform on
channel
A
is
pulsed.
20.
Change
the
frequency
synthesizer's output
to
140
MHz.
Note
that
the
waveform
on
channel
B is
pulsed.
21. Force
the
phase/frequency
detector to
reach operational
limits
by
changing
the
output
of
the
frequency
synthesizer
to
145
MHz.
VERIFY
THE
N1
DIVIDER
22.
Refer to
the
HP
8340B/41B
Calibration
Manual
and
perform
the
N1
loop
frequency
check
as
described
in
the
Frequency
Range
and
CW
Mode
Accuracy
test
in
Section
4,
Performance
Tests.
23.
If
the
instrument doesn't
pass
this
test,
troubieshoot the
A37
PLL1
divider
or
the
A59
digital
interface
assemblies.
24.
After
performing
all
tests,
turn
the
instrument's
power
switch
to
STANDBY.
Remove
all
test
leads.
Remove
the
extender
board and
reinstall
the
A37
PLL1
divider.
Reinstall
all
cables
and
mounting
hardware.
HP
8340B/41B
20-30
Loops Assembly-Level
Troubleshooting
C-15/C-16

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English