Zenith Model G500 TransOceanic Radio (1949)

  

One of the more interesting Zenith TransOceanic radios, the G500 provides a bridge between 1940s and 1950s designs. It was manufactured for only 18 months, from 1949-1951, and it originally sold for $99.50.

Cosmetics

On the outside, the G500 looks nearly identical to earlier 8G005 models from the 1940s. It has the same big rotary dial inside a brass bezel, surrounded by a shiny black faceplate.

Inside the lid, however, you'll notice an obvious difference. The G500 has a large, handsome Zenith badge, proclaiming it as "The Royalty of Radios," where the 8G005 sets had a simple black circle. Compare the following photos (the G500 is on the left).

  

The G500 badge is part of the detachable WaveMagnet antenna, which is now secured to the lid with knurled brass screws rather than snaps as in the 8G005 series. You can read more about WaveMagnets in my 7G605 Clipper article.

The G500 also eliminated the flip-down compartment in the cabinet's bottom front, which earlier models had employed to stow an integrated user manual and shortwave broadcasting guide. In this and all later tube TransOceanics, this information was provided in a little gold-covered booklet that was clipped inside the rear cover.

Almost a decade later, Zenith revived the flip-down bottom panel with integrated manual in its transistorized 1000, 3000, and R-7000 model TransOceanics.

Electronics

The big difference between the G500 and earlier models was to be found under the hood.

The earliest TransOceanics used loktal type tubes, which have a glass envelope and a metal base that snaps firmly into its socket. That sort of tube was a good choice in the 1940s, especially for portable and military radios which would endure a certain amount of jiggling.

By 1949, however, the better choice was the all-glass miniature tube, which was cheaper to manufacture, and, thanks to its lighter weight, needing no snap-in base.

The G500 replaced the former 117Z6 rectifier tube with a solid-state selenium rectifier and it substituted a single 3V4 multi-function tube for the multiple tubes previously used for audio amplification.

The rear view shows the glass mini tubes. At the lower right of the chassis, no rectifier tube is visible as before; the newer selenium rectifier is mounted underneath the chassis.

The net result of these changes was to reduce the tube count from eight tubes to five, decreasing the manufacturing cost as well as the the power requirements, which extended the radio's battery life.

If you restore a G500, begin by replacing the electrolytic and paper capacitors, a routine procedure for all radios of this vintage.

You should also replace the selenium rectifier with a modern silicon diode such as type 1N4007, to avoid fire hazards (and a horrible smell!) when the old selenium rectifier burns out. You can learn about other TransOceanic restoration techniques in my 8G005 article.

Before starting any electronic restoration, you should get a schematic to guide your work and help you understand the electronics. TransOceanic service manuals can be obtained from Nostalgia Air or one of the other sources listed in our Parts page.

Final Thoughts

The G500 established the basic electronic design for all subsequent tube TransOceanics, the 500 and 600 models. Although later tube TOs changed in appearance, they all had essentially the same radio inside.

Because this TransOceanic was manufactured for a short time, it is more scarce than other 1950s sets. If you're lucky enough to find one, expect to pay a mild rarity premium, perhaps $150-$200 for a nice original model, compared to around $100-$150 for more common later editiions.

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