Eddystone 990R - Maintenance; General; Replacing a faulty fuse

MAINTENANCE
GENERAL
The
990R
receiver
is
suitable
for
continuous
use
under arduous
operating
conditions
and
should
require
very
little in the way
of routine
maintenance over quite
long
periods of
operation.
All components
with the
exception of
the semiconductors
are
guaranteed
by
the
Manufacturer
for
a
period
of
one
year from
date of purchase.
The
semiconductors
are
covered
by a separate
guarantee.
As
with
all
Eddystone
receivers,
the
990R
can
be returned
to
the
Manufacturer at
any
time
should
major
servicing
become necessary.
The receiver can
be
sent direct or
via
one
of
the
many
Eddystone
Agents,
the
latter
course
often being
the most convenient
since
the
Agent
will
usually
have a
suitable
packing
case
in which
to return it. If
there is
no
local
Eddystone
Agent and
it
is
necessary
to send
direct, prior arrange-
ments
should
be
made
before
despatch.
It
is
most
important
that the
receiver is well
protected
against
damage
during
transit
and the
reader
is
referred to the Guarantee
Card
for
further
information
on
this
point.
Always
quote
the
Serial No.
of
the
set in
all
communications
.
Spares
for
user-servicing
can
be
supplied
and
helpful advice will
be freely
given
when
necessary.
Any
enquiries
relating
to
service
matters
should be directed to
the
"Sales
and
Service
Dept."
at
our
usual
address.
The
following
paragraphs
are
devoted
to
minor
servicing
and will
be
found useful if
it
becomes
necessary
to
replace
fuses,
lamps
etc.
Periodic
cleaning of the receiver
should
be
carried
out as
a
matter
of course,
care
being taken
to
avoid displacing
any
components
when
cleaning
the
interior.
Pull
instructions
for carrying
out re-alignment
will
be found
later
in
this
Section.
Lubrication
.
The gear
drive
and
other
mechanical
arrangements
will
not
normally
require attention
since
these
are
treated
with
a
permanent
lubricant
during initial
assembly.
If further
lubrication
is
thought
necessary
after the
receiver has been in
use
for
a
prolonged
period,
this
can
be
carried
out
with
a
light mineral
oil
suited
to the
temperature
conditions
under
which
the
equipment
is
operating. Care should be
taken
to
use
only
the smallest
amount
of
oil
necessary
for
free and easy
movement.
Replacing
a
faulty
fuse
.
Separate
AC
and
DC
fuses
are
provided
for
protection of
the
990R receiver. Ratings
are
1A % DC
and
$00mA
% AC
200/260V
(increased to
1A for IOO/
13
OV),
the fuses
being
standard
ljr"
x
i"
cartridge
types.
Circuit
arrangements are
such
that either fuse
could
fail
when
operating
from
AC
mains, whereas
on
DC only
one
fuse
(PSl)
is
in
circuit
. In
the
latter
case
the fuse also
protects the receiver
in
the
evont of
the
12V
supply
being
connected
with
reversed
polarity.
The fuseholders
are at the rear
and
spare
fuses
in
clips
on
the
right-hand
side-plate.
Range
Indicator
Lamps .
These can
be
changed
quite easily
after
removal
of
the
cabinet. Bulbs
are
L.E.S.
type
rated
at
6
V
50mA
(Eddystone Part
No.
66
59P)-
Holders
are
retained
in
rubber
grommets
and
can
be
extracted
by
pulling
gently away
from the
lamp assembly.
Cleaning
the
scale
window
.
After a
long
period
of
use,
especially
in
dusty
locations, it
may prove necessary
to
clean
the
inside
of
the
scale
window.
To do
this, take
off
the
window escutcheon
by
removing
the
four
retaining
screws.
The
window,
which
is of perspex, can now be
with-
drawn
and
should
be
cleaned
with
a
suitable
polish containing anti-static additive.
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