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VINTAGE RADIO
By JOHN HILL
Realism Realized – the Precedent
console receiver
A great deal of patience is sometimes needed
if one is to restore an old radio to its former
glory. My 1932 Precedent console was just one
such set.
This story started about five years
ago in a junk shop in Castlemaine,
Victoria. There it was in all its faded
glory – a rather sad looking “Precedent” console radio cabinet with
turned legs. The dial escutcheon bore
the motto “Realism Realized”.
Unfortunately, that’s all there was
– it was just an empty cabinet and it
was not in very good condition either.
It had been wet many times and was
quite shabby looking in appearance.
However, those of us who collect old
radios can picture in our mind’s eye
what these wrecks looked like when
they were new and, more importantly,
what they can look like again when
restored. As the old cabinet had fair
prospects, I offered half the asking
price and it was mine.
No innards
From that time on, the cabinet took
up residence in my shed and nothing
was done to it for the simple reason
that there were no innards to put in
it. I also realised that, because of its
poor condition, the woodwork would
require more professional refurbishing
than I was able to give it.
This home-made bearing (left) solved
a troublesome dial problem. It was
turned up on a metal-cutting lathe in
the author’s workshop.
Let’s face it: we can’t be good at
everything and restoring dilapidated
old radio cabinets is not my strongest
point.
To cut a long story short, I was
able to locate a complete Precedent
(a legless console) with the same dial
and control positions. It took a few
months to talk the owner into selling
it but eventually I became the proud
owner. Naturally, my intention was to
fit the innards of the legless console
into the old turned leg cabinet. I also
hoped that I would be able to sort out
the mess under the chassis for there
appeared to be many modifications to
the original circuit.
Incidentally, dates pencilled onto
the underside of the chassis indicate
that the set was made in October 1932.
So we are talking about a 60-year old
radio: one of those classics from the
early 1930s.
The background
The Precedent’s dial escutcheon bears the motto “Realism Realized”. It is a
typical half-moon dial from the early 1930s.
52 Silicon Chip
We are going to do a bit of side
tracking now but it is all part of the
Precedent story.
A friend by the name of Peter Hutton visits me occasionally and as Peter
is a fellow radio collector, we have
some rather lengthy conversations
when he calls. Peter is more than a
vintage radio enthusiast; he also runs
a TV and video repair service and is
a co-owner, with his brother David,
of the Melbourne Wireless and Sound
Museum at Peninsula Boulevard,
Seaford, Victoria.
One of the reasons Peter visits me
is to see if I have anything interesting
for sale and it’s not often that he goes
away empty handed. He also offers a
reasonable price for anything he wants
– not like some collectors I know!
On his last visit, I decided that it
must be about time the money flowed
the other way for a change, so I let him
take away the old Precedent cabinet
for restoration. Peter does refurbishing work and that old weather-beaten
cabinet needed his professional touch.
Among other things, the top of the
cabinet required re-veneering, a rather
specialised job to say the least.
Apart from cabinet restoration work,
The Wireless and Sound Museum
offers a wide range of services to the
vintage radio enthusiast, all of which
are carried out on the premises. I will
go into that aspect some other time.
When the Precedent cabinet was
returned, I was very pleased with the
job. Looking closely, one can see that
the original surface was a bit rough
and weathered but the overall refurb
ishing is as good as could have been
done considering the condition of the
woodwork. It really did require the
magic wand treatment and the old
cabinet has responded well to many
hours of diligent work.
The “U” section chassis of the old Precedent was fitted with timber ends.
Although the resulting set-up was not very rigid, such construction techniques
helped keep production costs down – an important consideration in 1932!
The restoration of the receiver itself
was also far from simple and it needed
considerably more time than is usually
required.
Perished rubber
One of the biggest problems was
the perished natural rubber-covered
wiring that was used extensively
through
out the set. This insulation
had broken away in many places,
particularly where the wiring went
through small holes in the coil cans,
IF transformer cans and the chassis.
All these leads had to be replaced in
order to prevent short circuits and
potentially dangerous situations.
Considerable care must be taken
when doing rewiring of this nature to
make sure that everything goes back
the way it was. Just one connection
in the wrong place can cause a lot of
trouble and inconvenience. Replacing
one wire at a time is a good policy in
this situation.
One of the IF transformers had an
open winding which was easily located. Green corrosion highlighted the
trouble spot in one of the fine leads
and it was repaired by bridging the
Above: this close-up view shows the friction dial set-up. The
small hole & its associated slit at the top of the disc allows
light to shine through and illuminate the dial. At right is
the dismantled resistor stack. These wirewound resistors
are mounted one on top of the other, with insulating strips
between them.
January 1994 53
At least half of the original wiring had to be replaced because of perished
insulation. The aerial, oscillator and bandpass coils all needed rewiring.
gap with a piece of fuse wire. These
old IF transformers were wound
using single-strand copper wire on
wooden bobbins. Litz wire had not
come into general use in 1932.
Valve line-up
The Precedent’s valve complement
was relatively common for that era
and consisted of an 80 rectifier, 57
autodyne mixer, 58 IF amplifier, 57
detector and first audio, and a 47
output. The 47 output pentode is one
of the few early AC valves that had a
directly heated cathode.
Many readers would know simply
by the valves used that the old Precedent was an autodyne superhet with
anode bend detection and no automatic gain control. This type of receiver
was fairly standard in the early 1930s.
However, the Precedent had a few
oddities about it that were different to
the norm. One of these peculiarities is
the “resistor stack”.
All the wirewound resistors in the
set are wound on flat fibre formers with
a solder tag at each end. These strip
resistors are drilled at the ends and are
mounted one on top of the other in a
stack. There are four such wirewound
resistors and they are separated from
each other by an insulated strip. One
of the photographs shows a dismantled
resistor stack.
This resistor stack caused just one
of the many problems encountered
with the restoration, as one of them
had gone open circuit. Fortunately, the
break was at one end of the winding
The tuning capacitor is a plain bearing type with two
collars & set screws to control end float. Plain bearing
tuners often require cleaning & lubrication if they are to
work smoothly.
54 Silicon Chip
and was easily repaired by reconnecting it to the solder tag.
When restoring a receiver of this
nature, it is advisable to measure
and label such resistances. A known
resistance is easier to replace than an
unknown one should it break down at
some time in the future.
Another oddity was the 2µF paper
capacitor that is used as a cathode
bypass on the output valve. Normally,
a low voltage electrolytic type is used
in this situation.
However, one must remember that
this set was built way back in 1932
when “dry” electrolytics were in their
infancy. Although they could have
been around at the time, they may not
have been reliable units – hence the
large paper bypass capacitor.
Dial problems
Another problem was the friction
drive dial mechanism. Although
the drive had plenty of friction, the
bearing that the control shaft turned
in was very worn and allowed the
control shaft to lift. This movement
was sufficient to let the friction drive
parts come out of engagement and lock
up the works.
Having a metal cutting lathe in my
workshop helps to solve many worn
dial problems and this occasion was no
exception. A new bearing was turned
up in hexagon brass (see photograph)
and the dial drive now functions as it
was meant to. Without the lathe, worn
dial parts could present some really
nasty problems that would be difficult
to overcome.
All the old paper capacitors, including the 2µF unit men
t ioned
The IF transformers required rewiring due to damaged
insulation on the original wiring, particularly where this
wiring passed through holes in the cans. All leads were
replaced to prevent short circuits.
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DEGAUSSING
WAND
This view shows the 80 rectifier valve (left) & the 47 output valve. The chassis
cleaned up quite well for a 60-year old receiver. The two terminals at bottom
right are for a gramophone pick-up.
earlier, were replaced with modern
equiv
alents. Likewise, the original
chassis-mounted high-tension filter
electro
lytics. These were replaced
with new 10µF 450V units.
Another capacitor that needed attention was the tuning capacitor, an
old 3-gang type with plain bearings.
It was in really good condition for its
age and only required cleaning and
lubricating. The thrust bearings were
also adjusted to prevent end float and
to prevent the plates from touching
each other.
As luck would have it, there were
no problems with the old loudspeaker.
The cone was OK, as were the field
coil and the output transformer. It's
not unusual to strike trouble here, as
open circuit field coils are a common
problem.
Worth the effort
Now that the Precedent is back
together and working again it looks
rather good and was well worth the
effort and expense. In reality, however,
its performance is no better or worse
than any other 5-valve autodyne receiver from the early 1930s. All these
sets seem to have a slight amount of
distortion (due to the anode bend
detection) but most people would
be unaware of this minor fault. By
transistor radio standards, it sounds
magnificent!
Although some vintage radio collectors can boast about the beautiful
original receivers in their collections, most of us have to make do
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$97.00 + $4.00 p&p.
SILICON CHIP COLOUR TV
PATTERN GENERATOR
Built-up kit comes with power plugpack, RF
lead. $250.00 + $9.00 p&p.
This view shows the finished receiver
in its refurbished cabinet. It’s quite a
stylish outfit if you happen to like old
console radios.
by scrounging for what leftovers are
still around today. Even so, by using
skilful repair techniques, enlisting the
services of experts and combining the
best parts of several radios into one,
the end result can be very pleasing. I
believe my 1932 Precedent to be one
such receiver.
The Precedent may not really be
“Realism Realized” by today’s standards but in 1932 it may well have been
SC
very close to it!
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Phone (02) 774 1154 Fax (02) 774 1154
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January 1994 55
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