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Well,
it's time to get started. Once the back/bottom card panel has been
removed, the first job is to remove the knobs. Their fastening screws
are accessed through slots underneath.
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Before
removing the cabinet, don't forget to unscrew the wire that connects
the internal cabinet foil to the chassis.
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Then, once the four
screws holding the cabinet to the chassis at the rear have been
undone, the cabinet simply slides forward off the chassis.
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This
set looks a good 'un.
The
lower RF/IF deck is unscrewed and slid out from the rear of the
chassis. But first, the multipole connector must be carefully eased
out from its socket (arrowed).
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Next
it's good practice to remove the tube before any operations are
carried out on the chassis.
There's a rim band
at the front to undo, the EHT connector and the tube socket to remove.
Also a clamp screw (arrowed right) and two focus magnet mounting
screws (arrowed left) must be undone...
In this set the ion
trap magnet (not shown here - previously it had been sitting near
the blunt end of the left arrow) had already been removed
to facilitate tube testing.
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...and
lastly not forgetting the multipole connector feeding the scan coils.
The tube can then
be lifted carefully off complete with the focus magnet supported
with one of the hands. Some may prefer to leave the focus magnet
bolted in position on the chassis and carefully withdraw the tube
neck forward through it.
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It's
a nice idea at this stage to date the set. A couple of capacitors
here say March and April 1951 so the set was likely manufactured
shortly after that, in fact just in time for the 'Festival of Britain',
which opened in May.
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Having
removed its surrounding can, time for a quick look at the line output
transformer. There's some melted pitch - evidence of previous overheating.
Rusty laminations can cause this, though in this case I am strangely
optimistic these will prove OK.
Before work on the
chassis starts, the LOPT will be taken off and its pitch coating
removed. More anon...
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The next thing will
be to clean down all the various major components which make up
the insides of this set.
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One
of the bits that should come off is the scan coil assembly on the
tube neck. This is often very tight. An application of WD40 should
soften the wax, though be careful not to get any on the tube's aquadag
coating.
Always wear goggles
when handling a tube, even one that seems as robust and inoffensive
as this one !
Gentle twisting and
upwards pressure was applied on the scan coils with the fingers
placed under the ring at the bottom (arrowed) and after an initial
jerk the scan coil assembly slid easily off the neck. When applying
pressure, don't be tempted to grip the metal lamination housing
or you could damage the scan coils beneath.
As the scan coils
emerge over the tube base at the end, be sure to simultaneously
gently push down on the base, since sometimes the bond may be weak
and it may become detached.
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