Sparton Model 558 Sled (1937)
The Sparton 558 sled is a
deluxe version of the model
557 that appeared one year
earlier, in 1936. Although
similar in the basics, the Walter
Dorwin Teague designed 558
features extended engraving
of the front mirror plus
engraving of the top and left
mirror panels. By contrast, the
model 557 has no markings on
its top or left sides.
A distinctive feature is the dark
banding etched into the front
and top mirrors. Each band's
disjoint nature creates the
illusion of depth, with the top
especially appearing to be
fabricated from two mirrors,
one atop the other. Such was
Teague's design genius.
deluxe version of the model
557 that appeared one year
earlier, in 1936. Although
similar in the basics, the Walter
Dorwin Teague designed 558
features extended engraving
of the front mirror plus
engraving of the top and left
mirror panels. By contrast, the
model 557 has no markings on
its top or left sides.
A distinctive feature is the dark
banding etched into the front
and top mirrors. Each band's
disjoint nature creates the
illusion of depth, with the top
especially appearing to be
fabricated from two mirrors,
one atop the other. Such was
Teague's design genius.
The receiver is a two-band
5-tube ac-powered
super-heterodyne. It covers
standard broadcast and
shortwave. The tube line-up is
6A8G (mixer/LO), 6K7G (IF),
6Q7G (2nd detector/AGC/1st
AF), 6F6G (AF power), 5Y3G
(rectifier). Schematic.
5-tube ac-powered
super-heterodyne. It covers
standard broadcast and
shortwave. The tube line-up is
6A8G (mixer/LO), 6K7G (IF),
6Q7G (2nd detector/AGC/1st
AF), 6F6G (AF power), 5Y3G
(rectifier). Schematic.
The Sparton model 558
features upgraded electronics,
including 4 knobs on the front
panel compared with the 557's
three. From left to right the
knobs are:- band selector,
tone, tuning and volume/on/off.
Coverage is of the standard
broadcast and shortwave
bands.
features upgraded electronics,
including 4 knobs on the front
panel compared with the 557's
three. From left to right the
knobs are:- band selector,
tone, tuning and volume/on/off.
Coverage is of the standard
broadcast and shortwave
bands.
Originally, the black trim on the
radio had a crystalline
appearance like that seen on
my model 557. This effect was
created by spraying with a
mixture of black laquer and
naptha*. It is missing on my
model 558, indicating that it
has been re-finished at some
point in its past. It seems that
many of the sleds I see have
been likewise re-finished, so
perhaps the addition of the
Naptha to the lacquer
weakened its adhesive
properties and rendered it
more prone to flaking away.
radio had a crystalline
appearance like that seen on
my model 557. This effect was
created by spraying with a
mixture of black laquer and
naptha*. It is missing on my
model 558, indicating that it
has been re-finished at some
point in its past. It seems that
many of the sleds I see have
been likewise re-finished, so
perhaps the addition of the
Naptha to the lacquer
weakened its adhesive
properties and rendered it
more prone to flaking away.
The engravings on the top and
left-side mirrors are clearly
evident in the two photographs
to the right. Again notice the
illusion of two upper mirrors
produced by the disjoint dark
band and engravings.
left-side mirrors are clearly
evident in the two photographs
to the right. Again notice the
illusion of two upper mirrors
produced by the disjoint dark
band and engravings.
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