This
rather large suitcase radio is powered by either dry batteries or mains.
There are some unusual features about it, but they are all to do with
the presentation. The circuitry is conventional, using the standard B7G
miniature range DK91 osc./mix., DF91 IF, D
A
F91 det/LF and DL94 audio output. Mains power is
selected by a switch system and is obtained via an isolating
transformer, with full-wave rectification via metal rectifier.
The
case, however, is where the oddities occur.
A
lmost all of it is made from steel sheet – the
control panel, the body of the case and the pressing for the base. Only
the lid, which houses the frame aerial, is built from wood and
hardboard. This is clearly because the aerial would not work in a metal
case!
The
handle is designed to open the radio as well as carry it, with the metal
ends of the strap rocking to release two internal pin-type latches. In
the open position, the frame aerial is vertical. The lid is restrained
in this position by what looks exactly like two short lengths of sink
plug chain. These are spring-loaded and retract into the body of the
case through two eyelets, one each side of the fascia.
It
was very obvious that the set would need recovering. The grained rexine
was in a dreadful state – torn and badly discoloured but worse still,
a visible ‘lumpiness’ gave an early warning of severe rusting.
A
t least it wasn’t woodworm! Off came the coverings.
New rexine was obtained but before recovering could be done, the rusted
case was cleaned up with an abrasive flap-wheel on a power drill.
A
fter a thorough coat of rust killer, which itself had
to be killed with meths, the covering began.
PV
A
adhesive was used to replace the rexine on the
wooden top cover, with high-strength carpet spray adhesive proving the
best for the metal remainder of the case.
Chassis
work
The
base of the set unscrews via the large, circular metal feet.
Access can then be had to the interior for battery
replacing or for the stored mains lead. Easily visible is the SenTerCel
full-wave metal rectifier. Its fins are supplied by a mains transformer,
making this set
A
C mains or battery only, no DC. Of course this makes
for a safer set, but beware the mains input side of the transformer! The
chassis is removed by slackening two 4B
A
nuts that clamp it to a bracket, then a further four
4B
A
nuts hold the chassis to the front plate and these
are easily located and removed, but difficult without a nut driver. The
inner lid panel covering the frame aerial must be removed before the
three connections can be unsoldered.
The loudspeaker had to be removed
for cleaning.
A
very large amount of fluff was carefully brushed out
of the cone, both back and front. The expanded metal grille had been
sprayed the same cream as the front panel and as this paint was in good
condition, a simple clean-up with washing-up liquid was all that was
needed.
A
piece of gold loudspeaker fabric sat beneath the
open mesh of the grille. This too was in good condition and a gentle
vacuuming brought it back to life. The dial ‘glass’, a panel of
moulded Perspex, was polished with metal polish to remove surface marks.
After detaching the spring steel dial pointer from the
parallel cord runs either side of the dial plate, the printed metal dial
itself was dismounted from the four long 6B
A
bolts and tubular spacers that secured it.
A
fiddly job due to the small nuts and star washers
that had to be held as the bolts were unscrewed.
Finally, after cleaning
the chassis front generally, the brass cord pulleys were found to be
rusted in place and a good freeing up and a dab of grease was needed to
restore smooth action and stop the cord slipping on its drive spindle.
The tuning capacitor needed similar lubrication on its ball-bearing
rotor supports. Severe crackling had been noticed at the top end of the
dial on both medium and long waves and this was found to be due to the
tuning capacitor outer rotor vanes making contact with the fixed vanes.
Slight leverage cured this problem.
A
replacement det/AF valve was needed to bring the set back to life.
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