DSI R-110 User manual

August 13, 1991
WO
MAINTENANCE MANUAL
FOR THE
R-110
and
R-110B
RECEIVERS
THIS
MANUAL
IS
INTENDED
FOR
USE
WITH
THE
FOLLOWING
SERIAL NUMBER:
i
Dynamic
Sciences
International
Inc.
6130 Variel Avenue
Woodland Ilills. CA 91367
[phone]
Fax:(818)
226-6247

SECTION 5. MAINTENANCE
5.1 Introduction
Three levels of maintenance are discussed in this section: preventive maintenance, periodic maintenance, and
corrective maintenance. Periodic maintenance is part of preventive maintenance and includes a receiver
performance test. Failure of a particular part of the performance test should lead to initiation of corrective
maintenance, and will indicate a starting point for fault isolation. Isolation procedures are provided down to at
least the module level. Disassembly procedures are also provided as an aid to service personnel.
Finally, field calibration procedures are included both for periodic maintenance and for replacement of failed
assemblies. Procedures for adjustments which may be made at the factory before shipment and which should
never need recalibration are not included.
§.2 Preventive Maintenance
Preventive maintenance includes correct installation and connection of the radio, periodic inspection and cleaning,
and execution of the receiver performance test. See table 5-1.
The model R-110 receiver requires a minimum of periodic maintenance unless abusive conditions exist. Such
conditions include improper handling, mounting, and operation, or environmental extremes.
§.2.1 Performance Test
The performance test consists of a procedure which, if followed all the way through, will demonstrate that the
receiver is in good operating condition. The performance test makes no attempt to verify all specifications, as
would an acceptance test procedure, but is rather intended to verify its basic operation. A full verification of
the radio’s specifications requires execution of the ATP.
Test equipment required by the performance test is listed in table 5-2. Receiver test points used by the
performance test are indicated in figure 5-1. A sample data sheet for recording the results of the performance
test is given in paragraph 5.2.1.2.15,
Field service adjustment procedures are provided at the end of this section.
R-110
Technical
Manual
Page
5-1

Table 5-1: Preventive Maintenance
Task
Interval
Description
Inspect Cables
4 Months
Check for frayed cables and wires. Check
that wires and coax cables are not
crimped between structural members.
Inspect connectors.
Inspect and clean air inlet
filter
4 Months Visually check for accumulated dirt; if
excessive, remove dirt and other deposits
with a vacuum
cleaner or compressed air.
Inspect plug-in modules
12 Months Look for discoloration of resistor and
capacitor coding bands or loss of coating
that would indicate abnormal operation
such as extreme heat conditions.
Clean connectors
12 Months Dissolve and wipe away any grease
deposits on front and rear panel
connectors. Use a cotton swab
dipped in Freon TF or alcohol.
Clean chassis
12 Months Wipe all dust and grease from the
interior and exterior chassis parts. ||
Execute performance test
and alleviate any identified
faults
12 Months Perform thorough testing of the receiver
to ensure that specified performance
is maintained.
Table 5-2:
Test Equipment for the Performance Test
Type
Specifications
Example
Signal Generator
10 Hz - 1280 MHz Hewlett Packard 8662A
AM, CW
Spectrum Analyzer 10 kHz - 1.8 GHz Tektronix 7L14
Oscilloscope 300 MHz Bandwidth Tektronix 2465
Frequency Counter 10 Hz - 3 GHz Hewlett Packard 5386A
IEEE-488 Controller Computer With Directly HP-85
(Optional)
Controllable Interface
R-110 Technical Manual Cc

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Figure 5-1: Test Points for the Performance Test
R-110
Technical
Manual
Page
5-3

§2.1.1 Setup
The
performance
test
is
based
on
a
standard
test
setup.
This
is
as
follows:
C
©
The
radio
is
in
its
powerup
condition:
Tuned frequency = 100 MHz
Input select = input #1
Input attenuation = 20 dB
Gain = 50 dB
Bandwith = 1 MHz
Detection = linear
BFO, Z axis, autorange, AGC disabled
Tune mode selected, 1 MHz tuning display digit selected for tuning
© A signal generator is connected to the radio’s #1 input:
Frequency = 100 MHz
Amplitude = -60 dBm
Modulation = unmodulated CW
© ‘The radio’s #2 input is terminated in 50 Ohms.
©
A
spectrum
analyzer
is
connected
to
the
radio’s
21.4
MHz
IF
monitor
jack
(not
the
"signal
monitor"
jack):
Center
frequency
=
21.4
MHz
Reference
=
+10
dBm
C
©
An
oscilloscope
is
connected
to
the
radio’s
video
output
jack
through
a
50
Ohm
feed-through
terminator:
Sensitivity = 0.5 V/div
Coupling = DC
Trace position = bottom of screen
Many
of
the
test
steps
will
call
for
variations
on
this
basic
setup.
These
variations
will
be
described
at
the
point
at
which
they
are
required.
Page
5-4
R-110
Technical
Manual

§.2.1.2 Procedure
The performance test procedure is functionally divided into a number of test headings, each of which typically
contains a number of steps to be performed.
§2.12.1 Front Panel Operation
This test verifies the operation of those front panel controls and displays which interface with the controlling
microprocessor. Note that this is a test of the controls only, not the functions associated with them. Not
included are the BFO, Z axis, and audio gain control knobs. Several of the status indicators are also not
included because they require special equipment, or require that a hardware fault be induced. Some of these
indicators will be exercised in subsequent tests.
For this test the standard test setup is not required. An oscilloscope is required for the X axis test.
1,
Press the RF input select pushbuttons one at atime. Pressing one of these buttons should cause its
internal indicator LED to illuminate, and the LED in the opposite pushbutton to extinguish.
Press the RF input attenuation stepping pushbuttons one at atime. They should cause the value
indicated on the attenuation display to step up and down.
Rotate the IF gain control knob in both directions. The rotation should cause the value indicated
on the gain display to step up and down.
Press the IF bandwidth stepping pushbuttons one at a time. They should cause the value indicatated
on the bandwidth display to step up and down.
Rotate the tuning knob in both directions. The rotation should cause the value indicated on the
tuning display to step up and down, with the step size based on the selected (blinking) display digit.
Press the tuned frequency stepping pushbuttons one at atime. They should cause the value indicated
on the tuning display to step up and down, with the step size based on the selected (blinking) display
digit.
Enter the sequence "1234567890." on the keypad. The digits should be shown on the tuning display
as they are entered. Now press the "C" key. The display should revert to its previous indication.
Enter the sequence "1K". The display should indicate 1 kHz.
Enter the sequence "1M". The display should indicate 1 MHz.
Enter the sequence "1000H". The display should indicate 1 kHz.
Press the log detector pushbutton. Its internal indicator LED should illuminate. Press it again and
the LED should extinguish.
Press the BFO enable pushbutton. Its internal indicator LED should illuminate. Press it again and
the LED should extinguish.
R-110
Technical
Manual
Page
5-5

10.
11,
12.
Page 5-6
Press the Z axis enable pushbutton. Its internal indicator LED should illuminate. Press it again and
it should extinguish. With the Z axis enable pushbutton indicator LED illuminated, press the Z axis
invert pushbutton. Its internal indicator LED should illuminate. Press it again and the LED should
extinguish.
Press the STEP pushbutton below the tuning display. Its internal indicator LED should illuminate.
Press it again and the LED should extinguish.
With the STEP pushbutton indicator LED extinguished, press the-SELECT pushbutton a few times.
The blinking digit selection on the tuning display should move left and then wrap around to the right
end of the display.
With the STEP pushbutton indicator LED extinguished, press the SELECT> pushbutton a few times.
The blinking digit selection on the tuning display should move right and then wrap around to the left
end of the display.
Press the alt mode pushbutton in at the bottom right of the keypad. Its internal indicator LED
should illuminate. Press it again and the LED should extinguish.
Enable autorange. The AUTO indicator should illuminate. Disable it and the indicator should
extinguish.
Enable AGC. The AGC indicator should illuminate. Disable it and the indicator should extinguish.
Enable absolute gain display mode. The ABS indicator should illuminate. Disable it and the
indicator should extinguish.
Enable delta gain display mode. The DELTA indicator should illuminate. Disable it and the
indicator should extinguish.
Enable CW gain distribution mode. The CW DIST indicator should illuminate. Disable it and the
indicator should extinguish.
Enable external wideband mode. The WIDE indicator should illuminate. Disable it and the
indicator should extinguish.
Set the bandwidth to 1 MHz and the tuned frequency to 1 MHz. The BW LIM indicator should
illuminate. Set the tuned frequency to 100 MHz and the indicator should extinguish.
Set the bandwidth to 10 kHz and the tuned frequency to 100 MHz. Select the 1 MHz tuning display
digit for tuning. The BW GAP indicator should illuminate. Select 1 MHz bandwidth and the
indicator should extinguish.
The AC HI, AC LO, REG, LOCK, FR OVL, BK OVL, MDC, and THRESH indicators should all
be extinguished.
R-110 Technical Manual
“
.

14.
Enter
tune
mode.
The
TUNE
mode
indicator
should
illuminate.
All
other
operating
mode
indicators
should
be
extinguished.
Enter
start
mode.
The
START
mode
indicator
should
illuminate
and
the
TUNE
mode
indicator
should extinguish.
Enter
stop
mode.
The
STOP
mode
indicator
should
illuminate
and
the
START
mode
indicator
should
extinguish.
Enter
step
mode.
The
STEP
mode
indicator
should
illuminate
and
the
STOP
mode
indicator
should
extinguish.
Enter
rate
mode.
The
RATE
modc
indicator
should
illuminate
and
the
STEP
mode
indicator
should
extinguish.
Enter
scan
mode.
The
SCAN
mode
indicator
should
illuminate
and
the
RATE
mode
indicator
should
extinguish.
Enter
store
mode.
The
STORE
mode
indicator
should
illuminate
and
the
SCAN
mode
indicator
should
extinguish.
Enter
recall
mode.
The
RCL
mode
indicator
should
illuminate
and
the
STORE
mode
indicator
should
extinguish.
Enter
reset
mode.
The
RESET
mode
indicator
should
illuminate
and
the
RCL
indicator
should
extinguish.
15.
Set
up
the
following
scan
parameters:
Start frequency = 100 MHz
Stop frequency = 200 MHz
Step size = 1 MHz
Step rate = 1 step/second
Repeat = none
Connect
an
oscilloscope
to
the
X
axis
output
connector.
Set
it
for
continuous
monitoring
of
DC
over
a0Q-
10
Volt
range.
The
initial
voltage
should
be
zero.
Initiate
an
upward
scan
using
the
SELECT
pushbutton.
The
indicator
LED
inside
the
pushbutton
should
illuminate
and
the
scan
should
commence.
Time
the
scan
to
completion.
It
should
require
100
seconds.
The
indicator
LED
inside
the
pushbutton
should
extinguish
at
the
end
of
the
scan.
The
X
axis
output
should
proceed
linearly
from
0
to
+10
Volts
during
the
course
of
the
scan.
Initiate
a
downward
scan
using
the-SELECT
pushbutton.
The
indicator
LED
inside
the
pushbutton
should
illuminate
as
the
scan
commences.
It
should
extinguish
at
the
end
of
the
scan.
16.
Select
front
panel
beep
volume
adjustment
mode
and
rotate
the
tuning
knob
back
and
forth.
The
piezo
transducer
should
sound
and
the
volume
should
vary
with
the
tuning
knob
position.
Plug
a
speaker
or
headphone
into
the
audio
jack
and
select
audio
beep
volume
adjustment
mode.
Rotating
the
tuning
knob
back
and
forth
should
produce
an
audible
indication
through
the
speaker
at
varying
volume
levels.
R-110
Technical
Manual
Page
5-7

17. Select display brightness adjustment mode and verify that the LED matrix character displays may be
dimmed and extinguished.
§.2.12.2 Power Supply Monitor
There are three power supply status monitor indicators on the front panel of the radio, for AC line high, AC
line low, and DC regulation. While it is not advisable to deliberately induce a regulation fault, it should be
possible to exercise one or both of the AC line monitors by adjusting the range switch on the rear panel. Note
that this test does not require the test equipment used by the standard test setup.
1. ‘It is assumed that the 120 VAC/220 VAC selection was properly made before initial use of the radio.
2. Rotate the AC subrange switch on the rear panel across its range. If the mains voltage is nominal
then one extreme setting should cause the AC HI indicator on the front panel to illuminate, while
the other extreme should cause the AC LO indicator to illuminate.
3. At least one setting of the AC subrange switch should cause both AC line indicators to extinguish.
If
more
than
one
setting
does
this
then
choose
the
one
which
is
in
the
middle
for
normal
use.
§2123 Reference Oscillator Output
Note
that
this
test
does
not
require
the
test
equipment
used
by
the
standard
test
setup.
It
does
require
a
frequency
counter,
however.
1.
Connect
a
frequency
counter
to
the
reference
oscillator
output
jack
on
the
rear
panel
of
the radio.
The
radio
must
be
warmed
up
for
at
least
1
hour.
2. Measure the frequency at the monitor connector. It should be 20 MHz to within a couple of Hz.
§.2.1.2.4 RF Input Selection
This
test
exercises
the
RF
input
select
relay.
It
is
also
the
first
throughput
test
of
the
signal
path,
so
that
many
other
problems
may first
show
up here
as well.
1.
Begin
with
the
standard
test
setup
described
in
paragraph
5.2.1.1.
A
clear
signal
should
be
present
from
the
IF on
the
spectrum
analyzer
screen
and-a
DC
offset
from
the
video
should
be
indicated
on
the
oscilloscope.
2.
Select
RF
input
#2
without
moving
the
signal
generator
connection.
The
indications
on
the
spectrum
analyzer
and
the
oscilloscope
should
fall
to
zero
(or
nearly
so).
3. Now reconnect the signal generator to RF input #2 and the 50 Ohm terminator to RF input #1.
The signals on the spectrum analyzer and the oscilloscope should be identical to those seen in step
1.
4,
Select
RF
input
#1
without
moving
the
signal
generator
connection.
The
indications
on
the
spectrum
analyzer
and
the
oscilloscope
shoud
again
fall
to
zero.
Page
5-8
R-110
Technical
Manual

a
§2.12.5 RF Input Attenuation
1.
Begin with the standard test setup described in paragraph 5.2.1.1. From the standard attenuation
setting of 20 dB, increase attenuation a step at a time and observe the results on the spectrum
analyzer. Each step should cause a 10 dB reduction on the screen.
Return to 20 dB of attenuation and set the signal generator to -80 dBm. Now step the attenuation
down. The indication on the spectrum analyzer should increase at 10 dB per step.
§.2.12.6 IF Gain Control
1. Begin
with
the
standard
test
setup
described
in
paragraph
5.2.1.1.
From
the
standard
gain
setting
of
50
dB,
use
the
gain
control
to
decrease
the
gain
and
observe
the
results
on
the
spectrum
analyzer.
The
IF
signal
should
attenuate
smoothly
and
linearly
through
the
entire
50
dB
range
of
the
control.
§.2.12.7 IF Bandwidth Selection
For
the 21.4
MHz
IF
bandwidths,
front
end
notse
is
used
as
a
broadband
source
and
the
effects
of
the
various
IF
bandwidth
filters
observed.
For
DCIF
bandwidths
a
signal
must
be
applied.
This
is
the
first
test
in
which
the
DCIF
module
is
used.
Up
until
now
it
has
not
been
in
the
signal
path.
1.
Begin with the standard test setup described in paragraph 5.2.1.1. Select RF input #2 so as to
monitor front-end noise.
Observe
the
noise
bandwidth
on
the
spectrum
analyzer.
At
the
standard
setup
bandwidth
of
1
MHz,
the
noise
bandwidth
(-6
dB
points)
should
also
be
1
MHz.
Note
the
video
output
level
on
the
oscilloscope
as
well.
Now
select
the
other
21.4
MHz
IF
bandwidths
(everything
available
down
to
and
including
80
kHz)
and
observe
the
noise
bandwidth
on
the
spectrum
analyzer.
In
each
case
the
bandwidth
shown
on
the
analyzer
should
match
the
bandwidth
setting.
The
video
output
should
remain
at
the
same
RMS
level
for
each
selection.
Select
RF
input
#1
and
20
kHz
bandwidth.
This
switches
in
the
DCIF.
Slightly
vary
the
signal
generator
frequency
to
find
the
-6
dB
points
of
the
bandwidth.
They
should
be
at
10
kHz
offset
from
100
MHz.
Make
sure
that
the
LOCK
indicator
is
not
illuminated,
since
this
test
initiates
the
use
of
two
synthesizers
which
were
not
previously
enabled.
Select
bandwidths
of
10
kHz
and
5
kHz.
In
each
case
check
the
bandwidth
at
the
output
by
varying
the
signal
generator
frequency,
and
verify
that
the
LOCK
indicator
remains
extinguished.
These
three
bandwidths
exercise
the
range
of
the
DCIF
filter
clock
synthesizer.
In
each
case
the
-6
dB
points
should
be
offset
half
the
nominal
bandwidth
from
the
tuned
frequency
of
the
radio.
R-110
Technical
Manual
Page
5-9

§.2.1.2.8
Tuning
Bands
and
Synthesizer
Range
This
test
checks
the
signal
paths
of
the
three
tuning
bands.
In
doing
so
a
few
extra
tuned
frequencies
will
be
included
to
run
the
programmable
microwave
and
low
frequency
synthesizers
through
their
ranges.
This
involves
taking
advantage
of
the
band
switching
hysteresis
available
when
using
the
tuning
knob
and
pushbuttons.
Note
that
this
test
is
the
first
point
in
the
procedure
at
which
the
low
frequency
RF
module
is
used.
1.
Page 5-10
Begin
with
the
standard
test
setup
described
in
paragraph
5.2.1.1.
Note
the
signal
level
indicated
on
the
spectrum
analyzer.
Tune
the
radio
to
1
GHz
and
set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Tune
the
radio
to
20
MHz.
Now,
using
the
tuning
knob
and
pushbuttons
BUT
NOT THE
KEYPAD,
step
the
tuned
frequency
down
to
13.5
MHz
WITHOUT
OVERSHOOTING.
Set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Tune
the
radio
to
7.5
MHz
and
set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Step
the
bandwidth
down
to
80
kHz
and
reduce
gain
to
return
the
signal
Jevel
on
the
spectrum
analyzer
to
where
it
was
before.
Now,
using
the
tuning
knob
and
pusbuttons
BUT
NOT
THE
KEYPAD,
step
the
tuned
frequency
up
Lo
16.499999
MHz
WITHOUT
OVERSHOOTING.
Set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Set
the
tuned
frequency
to
300
kHz.
Now,
using
the
tuning
knob
and
pushbuttons
BUT
NOT
THE
KEYPAD,
step
the
tuned
frequency
down
to
225.0000
kHz
WITHOUT
OVERSHOOTING.
Set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Set
the
tuned
frequency
to
200
kHz
and
set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analzyer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Step
the
bandwidth
down
to
500
Hz
and
reduce
gain
to
return
the
signal
level
on
the
spectrum
analyzer
to
where
it
was
before.
Now,
using
the
tuning
knob
and
pushbuttons
BUT
NOT
THE
KEYPAD,
step
the
tuned
frequency
up
to
264.9999
kHz
WITHOUT
OVERSHOOTING.
Set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
Tune
the
radio
to
1
kHz
and
set
the
signal
generator
to
this
frequency
as
well.
The
spectrum
analyzer
should
show
the
same
signal
level
as
before
and
the
LOCK
indicator
should
still
be
extinguished.
R-110 Technical Manual C

§2.1.2.9 Log Detector
The log detector and the linear detector use different signal pickoff points in the 21.4 MHz IF. In addition the
DCIF performs its own detection and bypasses the linear detector when it is used in linear mode. This test
checks the log detector both with and without the DCIF.
1.
2.
Begin with the standard test setup described in paragraph 5.2.1.1. Enable log detection.
Set the signal generator amplitude to produce 3.0 Volts of video as indicated on the oscilloscope.
Now step the radio’s RF input attenuation up and down and verify that each 10 dB step produces 0.5
Volts of change at the video output.
Set
the
bandwidth
to
20
kHz.
Adjust
the
signal
generator
for
3.0
Volts
at
the
video
output.
Stepping
the
input
attenuator
should
again
cause
the
video
output
to
change
0.5
Volts
for
each
10
dB
step.
§2.1.2.10 Overload Detectors
There
is
only
one
front
end
overload
detector,
but
there
are
three
for
the
back
end:
one
for
the
21.4
MHz
IF,
one
for
the
DCIF,
and one
for
the
video.
It
is
possible
to
test
each
one
separately,
using
different
combinations
of
radio
settings.
1,
Begin
with
the
standard
test
setup
described
in
paragraph
5.2.1.1.
Then
set
the
RF
input
attenuation
to
zero
and
gradually
increase
the
signal
generator
level.
The
FR
OVL
indicator
should
illuminate
when
the
signal
generator
is set
somewhere
between
-30
dBm
and
-20
dBm.
Return
to
the
standard
test
setup.
Then
gradually
increase
the
signal
generator
level.
The
BK
OVL
indicator
should
illuminate
at
a
signal
generator
level
of
around
-50
dBm.
This
is
a
video
overload,
Return
to
the
standard
test
setup.
Set
the
bandwidth
to
1
kHz
and
gradually
increase
the
signal
generator
level.
The
BK
OVL
indicator
should
illuminate
when
the
21.4
MHz
IF
level,
as
seen
on
the
spectrum
analyzer,
reaches
about
+6
dBm.
This
is a
DCIF
overload.
Return
to
the
standard
test
setup.
Set
bandwidth
to
15
MHz,
enable
log
detection,
and
gradually
increase
the
signal
generator
level.
The
BK
OVL
indicator
should
illuminate
when
the
video
level,
as
seen
on the
oscilloscope,
reaches
about
3.5
Volts.
This
is
a back
end
IF
overload.
R-110
Technical
Manual
Page
5-11

§2.12.11 Signal Monitor and Z Axis Outputs
The signal monitor and Z axis outputs are both sent to connectors on the rear panel. Signal monitor is taken
from the front end of the 21.4 MHz IF while Z axis is taken from the video. The Z axis output is provided with
controls which must be exercised.
1.
Begin with the standard test setup described in paragraph 5.2.1.1. Reconnect the spectrum analyzer
to the signal monitor output jack on the rear panel of the radio and verify the presence of the 21.4
MHz IF signal. Then return the analyzer connection to the 21.4 MHz IF monitor jack.
While maintaining the existing oscilloscope connection to the video output, connect the other
oscilloscope input to the Z axis output on the rear panel of the radio, using a 50 Ohm feed-through
terminator. Set the oscilloscope to monitor both outputs simultaneously. Set the signal generator
for
1
kHz
AM
modulation.
In
the
standard
test
setup
the
Z
axis
output
is
disabled,
so
there
should
be no output visible on the oscilloscope.
Enable
the
Z
axis
output
and
set
the
level
control
fully
clockwise.
The
Z
axis
output
should
show
the
AM
modulation
but
no
DC
offset.
The
displayed
modulation
level
should
be
about
1.5
times
that
—
present at the video output.
Rotate
the
Z
axis
level
control
counterclockwise.
The
Z
axis
output
should
reduce
to
zero.
Now
return
the
control
to
the
fully
clockwise
position
and
press
the
invert
pushbutton.
The
phase
of
the
Z
axis
output
should
reverse
relative
to
the
video
output.
§.2.1.2.12 Audio Output and BFO Detector
The
output
of
the
BFO
detector,
when
enabled,
replaces
the
output
of
the
other
detectors
in
the
audio
output
only.
Tests
of
the
BFO
and
the
audio
output
are
grouped
together
for
convenience.
1.
Begin with the standard test setup described in paragraph 5.2.1.1. Plug a speaker or headphone into
the
audio
output
jack
on
the
front
panel
of
the
radio.
Select
1
kHz
AM
modulation
on
the
signal
generator
and
verify
that
the
modulation
appears
at
the
audio
output.
Rotate
the
audio
volume
control back and forth and verify its operation.
_
Return
the
signal
generator
to
unmodulated
CW
and
enable
BFO
detection.
Rotate
the
BFO
control
back
and
forth
and
verify
a
zero
beat
near
the
midrange
position
of
the
control,
with
increasing
beat
frequency
on
either
side.
§.2.1.2.13 Autorange and AGC
Although
these
functions
are
implemented
very
differently,
they
perform
a
similar
function.
They
are
also
grouped
together
in
a
single
keypad
operating
mode.
1.
Page 5-12
Begin
with
the
standard
test
setup
described
in
paragraph
5.2.1.1.
Enable
the
autorange
function.
Now
vary
the
signal
generator
level
and
observe
the
input
attenuation
of
the
radio.
It
should
step
up
and
down
to
track
the
signal
generator
level
loosely,
with
about
13
dB
of
hysteresis.
Return
to
the
standard
test
setup
and
enable
AGC.
Reduce
the
signal
generator
level
to
minimum
and
gradually
increase
it.
The
video
output
level,
as
seen
on
the
oscilloscope
display,
should
level
off
as
signal
generator
level
increases,
approaching
about
3
Volts
as
a
limit.
R-110 Technical Manual
(

§2.12.14 IEEE-488 Interface
The
radio
makes
use
of
the
JEEE-488
interface
in
two
ways:
to
control
an
external
microwave
downconverter
and
to
accept
commands
from
an
external
host.
The
two
are
mutually
exclusive,
so
that
the
interface
may
only
be
used
for
one
purpose
in
any
particular
application.
If
the
interface
of
the
radio
under
test
is
not
being
used
then
the
test
is
unnecessary.
If
the
radio
is
used
with
an
MDC
then
demonstrated
control
of
the
MDC
is
a
sufficient
test
of
the
interface.
If
the
radio
is
remotely
controlled
by
a
host
then
demonstration
of
that
control
is
a
sufficient
test
of
the
interface.
A
desktop
computer
with
direct
control
of
its
IEEE-488
interface
1s
listed
in
the
test
equipment
table,
for
use
when
the
equipment
which
is
normally
connected
to
the
interface
is
unavailable.
When
using
this
computer
it
is
sufficient
to
take
control
of
the
radio,
issue
a
setting
command
to
it,
and
read
back
the
setting.
Factory-set interface address = 16
Example command = "FREQ 12345"
Example setting request = "FREQ?"
The return data in this case should be "1.2345E+4".
§.2.1.2.15 Sample Data Sheet
R-110
Technical
Manual
Page
5-13

Serial Number:
Front Panel Operation:
Power Supply Monitor:
20 MHz Monitor:
RF Input Selection:
RF Input Attenuator:
Gain Control:
Bandwidth Selection:
Tuning Bands:
Synthesizer Range:
Log Detector:
Overioad Detectors:
Signal Monitor:
Audio Output:
BFO Detector:
Autorange:
AGC:
IEEE-488 Interface:
R-110 RECEIVER PERFORMANCE TEST
—— Vv)
—___ VY)
—_ VV)
—— VV)
—___ V)
——._ Vv)
——. )
—— V)
— Vv)
—. v)
—___ v)
—— Vv)
—_ V)
—__ “)
——_ Vv)
—_ V)
— Vv)
SAMPLE DATA SHEET
Rev Level:
Comments:
Date:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Comments:
Test Operator:
(Optional)

§2.2 Fault Isolation
The R-110 is designed so that failures in the performance test, or other detected faults, may in most cases be
easily isolated to a single failing assembly. If a failure is detected in normal use then the performance test may
be of assistance in the first level of isolation, but in most cases the appropriate fault isolation procedure may be
identified and followed directly.
Hardware which is likely to fail will almost certainly be contained in one of the following modules:
© front panel assembly
Oo microwave RF module
© preselector module
© —_ low frequency RF module
© 21.4 MHz IF amplifier module and 21.4 MHz IF filter module
o DCIF module
° video module
© synthesizer section (microwave synthesizer module, low frequency synthesizer module, fixed LO
synthesizer module, plus parts of the microwave RF module and preselector module)
© power supply (part of rear panel assembly)
Fault isolation is normally to the level of one of the modules or assemblies listed above. In addition, some faults
may be further isolated within certain assemblies, such as the front panel or power supply. Replacement is
usually at the assembly level, but schematics and parts lists are provided in chapter 6 for isolation to the
component level.
Note that catastrophic power supply failures may require replacement of more than just the power supply.
Certain circuits in the R-110 can be damaged under conditions in which some power supply voltages are present
and others absent.
Note too that the section of the R-110 most susceptible to failure under extreme temperatures is again the power
supply.
Following is a list of typical fault conditions and fault isolation suggestions for each. It should be possible to find
an example which is similar enough to any major fault encountered to enable the-fault to be localized. Minor
faults, such as barely failing a spec involving end-to-end performance, may be more difficult to localize.
R-110 Technical Manuai Page 5-15

§2.2.1 Radio Completely Dead
If the radio does nothing at all when power is applied, and no front panel indicators illuminate, then there is a
problem in the power supply. First check the fuses, located in the AC input module on the rear panel. After
the AC input module the common power path includes the front panel power switch and the cabling to it across
the cardcage, the AC range switch on the rear panel, the fan, and the primary of the power transformer. If the
fan works properly then most of this, at least up to the transformer, is probably ok. If the fan isn’t working, then
the problem is probably in this area. Note that the front panel power switch connects to the rear panel assembly
with connectorized cables, which allows the front and rear panels to be separated from the cardcage. In
conditions of extreme vibration these connectors may come loose. The DC harness linking the cardcage and the
front panel assembly to the power supply also plugs into the rear panel assembly, so it too should be checked.
Next check the RF input select indicators on the front panel, which are located inside the RF input select
pushbuttons. These are controlled by opposite outputs of a flip-flop, so if +5 VDC is available to the front panel
control assembly then one or the other should be illuminated. Note that there are two separate +5 VDC
regulators in the power supply, one for the front panel and one for the cardcage.
If +5 VDC is present at the front panel then the processor and displays should be working and yielding
reasonable
indications.
If
the
power
supply
checks
out
but
the
front
panel
is
still
dead
then
check
the
mating
of the DC supplies to the front panel assembly (the 15 pin D-sub on the back of the assembly). If power is being
delivered
adequately
then
suspect
the
processor
PCB
in
the
front
panel
assembly.
5.2.2.2 Front Panel Displays/Indicators INuminated But Random
If +5 VDC is being supplied to the front panel assembly then at least some of the indicators should be
illuminated. If the displays and indicators make no sense at all then the problem is probably in the processor
PCB.
If
most
of
the
displays
and
indicators
appear
to
be
okay,
and
the
pushbuttons
appear
to
be
at
Jeast
partly
functional, then the problem is probably in either the switch/display PCB or the interface PCB, both in the front
panel
assembly.
The
pushbuttons
and
the
tuning
and
gain
controls,
the
LED
indicators
inside
the
pushbuttons,
and
the
LED
status
and
mode
indicators
surrounding
the
LED
matrix
character
displays,
are
all
sensed
or
driven
via
separate
connections
to
the
interface
PCB,
so
it
is
not
too
difficult
to
identify
which
PCB
is
at
fault
once
they
have
been
removed
from
the
front
panel
assembly
sheet
metal
to
allow
probing.
The
LED
matrix
character
displays
are
connected
in
parallel
to
a
control
bus
from
the
interface
PCB.
Each
display
consists
of
four
characters.
If
one
display
is
bad
then
the
fault
is
probably
in
the
switch/display
PCB.
If
all
six
are
out
then
it
is probably the interface PCB at fault.
The
front
panel
piezo
transducer
requires
+
/-
15
VDC
as
well
as
control
supplied
by
+5
VDC
to
operate.
If
it
is
not
working
then
either
it
or
its
on/off
switching
transistor
on
the
switch/display
PCB
may
be
bad,
or
the
DAC-controlled
voltage
driver
on
the
interface
PCB
may
be
bad.
If
neither
the
piezo
transducer
nor
the
audible
indicator
source
to
the
audio
output
amplifier
are
working
then
the
problem
is
in
the
interface
PCB.
Once
a
problem
has
been
narrowed
down
to
the
front
panel
assembly
control
circuits,
fault
isolation
to
one
of
the
three
PCBs
is
accomplished
by
taking
apart
the
front
panel
assembly,
removing
the
three
PCBs
and
re-
attaching
them
together
outside
the
sheet
metal.
The
15
pin
power
connector
may
then
be
re-attached
to
the
back
of
the
processor
PCB
and
the
tuning
and
gain
controls
may
be
dismounted
and
re-attached
to
the
switch/display
PCB.
This
results
in
a
complete,
working
control
assembly
without
the
surrounding
sheet
metal,
which
allows
probing
to
localize
a
fault.
Page
5-16
R-110
Technical
Manual

§.223 RF Input Selection/Attenuation Incperative
The RF input relays and attenuator are the only items in the radio which require the use of the +24 VDC
supply. The supply is the first thing to check. If it is okay but neither the input select relay nor the attenuator
work, then the driver IC on the interface PCB is probably at fault. If only one function is inoperative then it
may be a bad relay or attenuator, or one section of the driver IC.
Tuning in band 3 causes the front panel band select relay to direct the signal to the microwave module, while
tuning in bands 1 and 2 cause it to direct the signal to the low frequency RF module. Faults which may appear
to be caused by bad cardcage modules may be traceable to this relay (or the driver on the interface PCB) as
well.
§.2.2.4 Audio Output or X Axis Output Inoperative
The audio output amplifier and the X axis output buffer are located on the X axis/audio output PCB in the front
panel assembly.
The X axis output buffer uses the + /- 15 VDC supply from the cardcage. Its input comes from the interface
PCB in the front panel assembly, which uses a + /- 15 VDC supply based on a different pair of regulators. A
failing X axis output, given that the power supplies are good, is traceable to either the interface PCB or the X
axis/audio output PCB, or the coax cable linking them, which might possibly become pinched in the partition
during assembly.
The audio output amplifier consists of a front panel volume control, a preamp, and a power amp. All of the
circuitry except for the volume control are located on the X axis/audio output PCB. The preamp and power
amp are supplied by separate pairs of + /- 15 VDC regulators. The preamp shares its supply with the cardcage
and the X axis buffer, while the power amp shares its supply with the front panel control section, where it is used
by the DACs and amplifiers for the piezo transducer, the audio output beeper, and the X axis source.
The audio signal originates at the video module in the cardcage and is passed to the front panel assembly via
coax cable. It passes through the volume control and the preamp and is then combined with the audible
indicator signal from the interface PCB at the power amp. Thus if the audible indicator function works but there
is no audio from the video module, then the volume control and preamp are suspect. If there is neither audible
indicator function nor audio output then the power amplifier is suspect. If only the audible indicator function
is failing then first make sure that the programmed volume is not set too low, Then suspect the connecting cable
from the interface PCB, which can become pinched in the partition during assembly.
The X axis/audio output PCB has its own 9 pin D-sub power connector. If a failure is traced to this PCB then
make sure that the power connector is mating properly.
R-110 Technical Manual Page 5-17

522.5 One or More DC Supplies Inoperative
Here is a list of the DC supplies. Each listing has separate regulators, except for the +24 VDC supply, which C
is unregulated: 7
3°
°
°
o
+5 VDC for the front panel control section
+5 VDC for the cardcage and the front panel cardcage interface buffer
+24 VDC [or the front panel input relays and attenuator
+/- 15 VDC for the cardcage, the front panel audio preamp and X axis output buffer
+ /-15 VDC for the audible indicator and X axis sources, the piezo transducer, the RS-232 interface,
and the audio output power amp
+/- 8 VDC for the cardcage
+50 VDC for the cardcage
Cardcage
voltages
may
be
conveniently
measured
at
the
feed-through
capacitors
in
the
sidewall
of
the
cardcage.
Here
is
the
color
coding:
0000000
green: +5 VDC
brown: +8 VDC
blue: -8 VDC
red: +15 VDC
violet: -15 VDC
yellow:
+50
VDC
C
black:
ground
~
Table 5-3 shows the usage of the various power supplies.
Page 5-18
R-110 Technical Manual