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Latest
Restorations
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Model
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Hallicrafters
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S-107
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Sears
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132.884
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Philco
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19LZ
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Philco
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42-1008
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Philco
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48-1262
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Sears
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R1171
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Philco
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620
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RCA
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5QR-74FM
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Quasar
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67X1
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Blaupunkt
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2520
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RCA
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6K2
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Philco
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620
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RCA
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U-10
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Sears
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4465
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Atwater Kent
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165
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Stromberg
Carl
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1121-PG
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AK
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447
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Sears
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4565
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Philco
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40-517
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Truetone
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D708
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Stewart
Warner
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91-111
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Zenith
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10S464
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Philco
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49-1602
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RCA
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85K
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Capehart
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88P66NL
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Sparton
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410
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Olympic
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601-V
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RCA
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26X-4
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The top photo shows our mostly vintage
repair bench. We enjoy repairing test equipment as much as repairing
radios
The next photo is of our Western
Electric KS-15750L1 tube tester made by Hickok, arguably the finest tube
tester ever manufactured.
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Here is an Atwater Kent Model 92, an
eight-tube AM radio manufactured in 1932. The cabinet is
exceptionally attractive.
The oscilloscope shots that follow
show a 1200 kHz AM signal reproduced by the radio. The shots show how
a radio signal is transformed in to an audio signal
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1200 kHz signal at the antenna
terminal. The signal consists of a carrier wave modulated by intelligence
(sound)
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The same signal at the grid of the
mixer tube. The signal gained some amplification passing through the
antenna coil
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Signal has been mixed with the local
oscillator to create a 455 kHz signal, the intermediate frequency of this
radio
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Signal after passing through the
second detector. The carrier signal has been removed leaving only the
audio signal
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Final amplification stage of the
signal readying it for the speaker coil and your ears
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