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Vintage Radio
By Associate Professor Graham Parslow
A “vintage” radio from
just a front panel
It’s not really an authentic vintage radio but this
resurrected radio could almost pass for the real
thing. It all started with a front panel from the
1930s but it now hides transistors, not valves.
T
HERE’S A WAY to win vintage
radios at an auction – you simply
pay more than anyone else is prepared
to. At first, that’s exactly what I did,
by making liberal bids on eBay. So in
2007, I won the lot of radios shown in
the photo above for $385. The 1938
STC model 500-I (middle radio) was a
must-have and I would be quite happy
to pay $300 for one of these in good
condition.
The radios were on a farm 200km
out of Melbourne. Bob, who sold me
the radios, turned out to be a typical
affable country person and offered to
bring the lot down in his ute on the
next trip to Melbourne. We hit it off
98 Silicon Chip
rather well when he made the delivery
and we chatted quite bit.
The radios were in appalling condition and after Bob left I had a quiet
moment of reflection on the value of
my purchase. In marketing terms, this
is known as “buyer’s remorse”.
Relieving the remorse
Some of my despondency was
quickly relieved by simply getting
a hose out and washing the chicken
droppings off the 1946 Breville (the
righthand-side radio in the photo).
This was a radio that I did not personally value highly, so I was prepared to
be a bit cavalier about how I treated
it. But there are a number of reasons
why hosing down a plywood radio
from the 1940s is a bad idea, including
delamination of the ply and staining.
In this case I was luckier than I
deserved to be and that Breville still
remains reasonably intact on a shelf
waiting for me to restore it. That’s the
thing about projects; they get done
when you make time.
There is no great ledger saying you
have free time and this is what you will
do; projects get chosen by your motivation at the time and my highest initial
motivation was to restore the STC.
That restoration had a great outcome
and when I subsequently showed Bob
pictures of that STC radio, he called
it wizardry.
One of the great things about restorations is that they are not only personally satisfying but also a means of
sharing an interest with other people.
Bob told me that the radios I bought
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This L-shaped timber piece consisting of an ornate front panel (complete with
metal escutcheon) and baseboard was the starting point for the project. It was
probably made around the early 1930s.
attracted quite a few questions during
the auction, mostly about the facade
panel (top of the pile in the photo). It
subsequently spent a couple of years in
my storage shed in a prominent place
that I constantly walked past.
One day, it attracted my attention
and the decision was made to make
this the next project. This was appropriate since by that time my knowledge
of the history and technology had
become better honed, along with my
technical restoration skills.
box (wood or metal) with knobs and
connections for batteries, aerial and
speakers or headphones. The commercial radios of the 1920s made a
great feature of the tuning indicator
escutcheon. These were typically
made of brass and sometimes included
an enamel badge, as does the mantel
radio featured in this article.
The calibrated tuning dial was usually graduated from 0-100 and listen-
The baseboard was in quite poor
condition, due to delamination of
the plywood and was subsequently
discarded, leaving only the front
panel and the escutcheon.
ers would write down the numbers
for their favourite stations. As more
stations became available and manufacturers were better able to align their
radios consistently, they printed the
station call-signs on the dial, a feature
much preferred by buyers.
By the end of the 1920s, it was
evident that headphones were no
longer suited to a family radio and the
speakers were routinely incorporated
in the radio cabinet, rather than independently standing on top of it. The
Personal background
I was born in 1948 and raised in a
small country town in South Australia.
As a boy, I made crystal sets, tinkered
with simple electronic circuits and avidly read Radio, Television & Hobbies.
I brought home radios scavenged from
the local tip (mostly from the 1940s)
and took them to pieces.
When I began collecting radios in
my 50s, they were mainly the radios
of my early years, both valve and
transistor. As my collection grew, I
became more systematic in reading the
history of radio. This took me back to
the 1920s and the dawn of commercial
radio transmissions, encouraging the
acquisition of some 1920s sets, both
commercial and hand-made.
These 1920s radios universally conform to the coffin style: a rectangular
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The tuner, audio amplifier and power supply modules were transplanted
into the vintage cabinet from this old Sanyo radio-cassette player.
September 2012 99
sometime soon because then I will
have a valuable asset rather than what
my wife insists they are, ie, junk.
Be that as it may, an old Sanyo
radio-cassette player which no longer
functioned on the FM band was not
going to be missed. It was effectively
constructed using three separate modules: power supply (with mains transformer), tuner and audio amplifier.
Immediately, the possibilities were
evident, especially as the tuning capacitor was driven by a simple pulleywheel and the discrete volume pot
was separate from the circuit boards.
Putting it together
The 3-ply outer sheath was shaped by making multiple kerfs into the reverse
side of the ply, so it could be formed to the semicircular dome shape required.
natural outcome of this evolution was
the cathedral style of radio, spanning
roughly 1928-1935.
The starting point
As shown in the photos, the remarkably sparse starting point for this particular project was an L-shape of two
wooden panels (face and base), with
some moulding around the base. Most
restorers would place this fragment of
a once proud radio in a corner of the
shed or even throw it out but I saw it
as an inspiring cornerstone to a unique
project.
Ideally, every bit of the original material would be incorporated into the
final product, although that was not
the outcome here. Step one was simply
to put it on the bench and engage the
power of imagination. The constraints
were to produce a radio that not only
looked original but which also used
what was already on hand in my salvage bins if at all possible.
It was apparent the knobs had to
remain where the four holes were but
nothing I had in my salvage shelves
lined up at all well with those holes.
However, the project eventually came
to fruition after I made a large acquisition of 1980s boom-boxes and cassetteradios. As an aside, I hope that these
icons of the 80s become collectable
The power supply, tuner and audio amplifier modules from a old Sanyo radiocassette player form the heart of the resurrected “vintage” radio.
100 Silicon Chip
So the project was conceived as
a dedicated AM receiver with four
knobs controlling On-Off, Volume,
Tuning and Tone (top-cut). My metalbits box contained the case of what
was once an LKB electrophoresis
power supply and it provided a heavygauge aluminium bracket to anchor
the electricals. The aim was to anchor
the frame only to the front panel and
this was simply done by using wood
screws from the back.
Once the four holes were in place
for the knobs and a cut-out provided
so that the tuning dial could be viewed
through the escutcheon, the project
rapidly progressed to the point of
functioning. My knobs box had only
one radially-calibrated dial that I
could use as the tuning indicator and
this was scanned and reproduced onto
thin cardboard that would allow backillumination by a dial globe.
My knobs bin didn’t include a set of
four matching knobs that were genuine
1930s, so four instrument knobs with
pointers from the 1950s were selected,
initially to see what it would look like.
It looked modestly acceptable so the
pointers were removed from the knobs
and they remained part of the project.
Happily, a 12-inch (300mm) Magnavox speaker I bought in the 1970s
fitted snugly into the cathedral speaker
space.
At this stage, apart from some screw
holes at the rear, no physical alteration had been made to the casing. The
original radio was manufactured by
A. J. Veall Pty Ltd who were located
at 243 Swanston Street, Melbourne,
until they relocated to Bridge St, Richmond in 1954. They traded in a range
of electrical goods and in this respect
they were comparable to retailers like
Myers and Malvern Star, who subsiliconchip.com.au
This view shows the
general assembly. The
electronic modules
were mounted on an
L-shaped aluminium
bracket, while a
300mm Magnavox
loudspeaker from
the 1970s fitted
snugly into the cath
edral speaker space.
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The completed radio
looks just like the
1930s original but there
are no valves inside the
cabinet – just a solidstate transplant that’s
not only more reliable
than the original but
sounds better as well.
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September 2012 101
The refurbished “vintage” radio now looks quite at home in the lounge room,
where it is once again serving as a family radio.
contracted out for radios to be made
to sell as a house brand.
In fact, it’s likely that this mantel
radio was a house brand with limited
production, because a web search
failed to find any reference to the
brand.
The radio boom
Radio was a new boom in the 1930s,
driven locally by the resolution of
royalties for patents so that all comers could use the superior superhet
design through the ARTS&P system
in Australia. This meant that small
This old dial scale was scanned and the
image printed onto thin cardboard to allow
back illumination using a small globe.
102 Silicon Chip
companies could make their own radios, free from prosecution for design
infringements, by sub-contracting to
a cabinet maker and a radio chassis
fabricator.
This cottage industry was destroyed
by World War 2, for a number of reasons. When a mantel radio sold for
around 30 pounds, it became the pride
of the lounge-room as it probably cost
six months of hard-earned savings in
the era of the Great Depression.
For a manufacturer, it was worth
paying a pound extra to the cabinet
maker to use mixed veneers, inlay
some ebony and perform some fine
fret-work to incorporate a “fleur de
lys” design into the speaker opening.
After 80 years, many of them in
a country shed, my object of 1930s
craftsmanship displayed many cracks
in the aged veneer. However it did
remain largely intact due to the good
coat of shellac it started with.
So what to do with the wood-work?
Some hard decisions were needed
and the result was to discard the two
lengths of damaged moulding around
the base, because it was easy to purchase a new length of similar moulding. The baseboard was also quite poor,
due to delamination of the plywood,
so this too was discarded, leaving only
the front panel and the escutcheon to
become part of the end result.
Veneered 5-ply was adequate for
replacing the base and for making a
frame to hold a 3-ply outer sheath. The
professional way to mould plywood
is by using steam but I set up my saw
bench to make multiple kerfs into the
reverse side of the ply, so it could be
formed to the semicircular dome shape
required. With suitable gluing and
screwing, the case was made ready for
the finishing touches.
Remarkable results with timber
finishing have been achieved for centuries using natural products. By luck
more than design, Bayer in Germany
were looking for a Nylon-like polymer
to avoid DuPont patents when they
discovered polyurethanes which they
patented in 1937.
Purists may revel in using original
finishes but I am happy to use modern
finishes with all their advantages of
hardness, transparency and lustre.
However, I quickly learned from previous restorations that the old finishes
react badly with polyurethanes and
the first step must be to reach for the
paint stripper and meticulously clean
the cabinet back to the bare timber.
The first finishing step for the Mantel was to paint over the exposed edge
surfaces with a brown acrylic paint
that matched the original paint. The
face and case were separately painted
with polyurethane, so that the junctions did not fill. The first coat was
applied using solvent-diluted polyurethane with a brush to ensure that
the raw wood was adequately wetted
and penetrated.
This was followed by eight or so
applications of Wattyl Estapol from
spray cans. For a job of this size, it’s
inefficient to set up a compressor and
spray gun, however a brush used for
finishing coats is counter-productive,
with marks inevitably remaining
obvious in the hardened surface. So
multiple thin coats were carefully
sprayed on and sanded back.
Patience is essential at this stage to
allow each sparsely applied coat to
thoroughly dry before sanding back.
The very last addition to the mantel
was some speaker grille cloth. Then
with some satisfaction it was taken
to the lounge room and is now again
serving as a family radio.
The bass is rich and speech is clear.
What’s more, the authentic 1932 characteristics of 50Hz background hum
and delayed warm-up are features that
SC
I am happy to forego.
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