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überarbeitet am 3.11.2010
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The "Zenith Radio Corp." has been founded in 1924, it emerged from the "Chicago Radio Laboratory",
they started with the production of TRF receivers and after 1929 made superhet receivers. After the
big Depression, Zenith Radio Corp. quickly re-started production of radios.
After the polar explorer MCMillen had already carried a Zenith receiver on his expeditions in 1925,
in the year 1941, he was given a prototype of a receiver developed by Zenith since 1939. This radio
turned out to have exceptional shortwave performance and was still battery powered and portable.
The first "Trans Oceanic" did already cover not only mediumwaves but also five spread shortwave
bands from 49 to 16 meters. It was equipped with a telescopic antenna, a loop antenna for mediumwaves
and also the "Wave Magnet", a detachable short - wave loop antenna; the four tone switches of the "Radio Organ"
were also a special feature of the early "Trans Oceanic" radios.
The superhet 7G605 with seven tuned circuits was equipped with battery tubes but could also be operated
from 117 Volts mains; during the War Years, the cloth at the speaker grille did show an image of a bomber -
this receiver was highly estimated by soldiers in several theatres of war as it was a reliable source
of news from home.
In 1946, it has been replaced by the 8G005, the very popular model G500 equipped with miniature tubes
was sold after 1949. The 1951 model H500 probably was the most popular model, it still had the
characteristic round frequency dial, but it came with two shortwave bands (2-4 and 4-8 MHz) covering
also the tropical bands instead of the 49m band coverage found in older models. The H600 from 1953
came with a linear frequency dial and was the last tube equipped shortwave travel portable made
by Zenith.
The "Trans Oceanic Royal 1000" was the first solid state world band radio made by Zenith, the single
conversion superhet with a horizontal turret tuner arrangement made it's appearence on the market in 1957.
After the Royal 3000 from 1963 which also covered the FM broadcast band, the Royal 7000 was the last
classic solid state "Trans Oceanic" receiver, it featured a BFO for CW and single sideband
reception.
With the R 7000 introduced in the year 1978 and produced until 1981 had a similar design as
the Sony Earth Orbiter with it's horizontal turret tuner and fine tuning, Zenith could not catch
up to the receiver developed in Germany and Japan. From Sony or Grundig, You could get a shortwave
double conversion receiver with digital frequency display and shortly after even with PLL
synthesizer circuitry for nearly the same amount of money. The analog multiband radios with their
poor frequency dial were outdated, and the era of Zenith "Trans Oceanics" and with them the
era of travel shortwave radios developed in the USA came to an end.
Zenith Travel Radios
| 7G605 (1941/2):
Single conversion superhet, analog dial, MW / SW 49, 31, 25, 19, 16m |
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| 8G005 (1946):
Single conversion superhet, analog dial, MW / SW 49, 31, 25, 19, 16m |
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| G500 (1949):
Single conversion superhet, analog dial, MW / SW 49, 31, 25, 19, 16m |
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| H500 (1951):
Single conversion superhet, analog dial, MW / SW 2-4 / 4-8 MHz, 31, 25, 19, 16m |
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| L600 (1953):
Single conversion superhet, analog dial, MW / SW 2-4 / 4-8 MHz, 31, 25, 19, 16m |
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| Royal 1000 (1957):
Single conversion superhet, analog dial, LW / MW / SW |
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| Royal 3000 (1963):
Single conversion superhet, analog dial, LW / MW / SW / UKW-FM |
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Royal 7000 (1969):
Single conversion superhet, analog dial, LW / MW / SW / UKW-FM
BFO for reception of CW/SSB signals |
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R 7000 (1978):
Single conversion superhet, analog dial, LW / MW / SW / UKW-FM
BFO for reception of CW/SSB signals, RF Gain, 2 I.F. bandwidths |
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weitere Lektüre:
d: Weltempfänger Zenith Trans-Oceanic, Konrad Birker
in www.radiomuseum.org
e: The Zenith Trans-Oceanic - the Royalty of Radios, Bryant and Cones, Schiffer Publishing Ltd.
© Martin Bösch 2.11.2010
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