Sonora Globe Navigator Radio (1940)

           

This Sonora Globe Navigator from 1940 is a dramatic, unusual radio in the shape of a colorful world globe. Here are two views of it, from the front and the rear:

  

The names and borders shown on this circa-1940 globe portray a distinct time in history. In the first photo we see obsolete names like Hadhrumaut (part of present-day Yemen). The Navigator emblem appears off the west coast of North America, where names are more familiar:

  

It might seem appropriate for a globe radio to receive international shortwave broadcasts, but that degree of miniaturization wasn't practical in 1940. Inside the Navigator is a simple 5-tube radio that covers the AM standard broadcast band. The radio's small plastic base contains the power/volume control and a pilot light behind an amber lens:

This radio has one of the most unusual tuners that you'll ever see: it's the radio cabinet itself! You select a station by turning the entire globe, just as you'd rotate a conventional classroom globe on its axis:

Look closely at the previous photo and you'll see the tuning dial: a stationary red pointer and a moving circular scale with the familiar AM radio numbers (starting at 550 for 550 kilohertz). The large oval holes around the top of the case allow heat from the radio tubes to escape.

On the bottom is a label showing the tube layout, along with a chassis stamp (TSG) and a little serial number label:

  

The label gives us clues about how the radio is arranged inside. The large tuning capacitor must be attached to the globe's "North pole," while the rest of the radio chassis rotates when you turn the globe's case. That's a rather precarious arrangement (!), although I suppose it worked well enough when these radios were new.

The tube layout tells us this is a conventional "All American Five" radio with a series-string type power supply. The tubes are types 12A8GT, 12K7GT, 12Q7GT, 35L6GT, and 35Z5GT. You can download the Riders service manual from the Nostalgia Air website.

This note from the service manual shows that disassembling the globe to service the radio is a bit tricky.

I was a bit dismayed to read Step 1 of the procedure, which directs you to slit the globe's covering all of the way around the case, at the line of the equator. This explains why there's a gap between the upper and lower hemispheres of my globe, as you probably noticed in the earlier photos.

Of course, if a globe is totally sealed, cutting it open is the only alternative, but other globe designers solved the problem differently. In my Colonial globe, the designers put a metal ring around the equator and made it possible to separate the hemispheres and reattach them nondestructively.

The service note says that you will find two spare paper equator bands inside the globe. After repair is complete, you can glue on a spare band to make the globe look new again. That was a thoughtful touch, but I guess you were on your own after the third repair, and it was not at all unusual for a vintage radio to need at least a couple of tube replacements over the years.

I haven't opened up this radio to see whether it still has a spare equator band inside. Having restored other spherical radios, I can testify that they're tedious to work on, and the performance of simple AA5 radios with dinky speaker is generally mediocre. Perhaps someday I'll change my mind, but for the time being, I'm going to leave this radio unrestored and enjoy it as an interesting "shelf queen."

This is the third globe radio that I've found. Here's the Sonora with my two other globe sets: a Bakelite Colonial 700 from 1933 and transistor Vista NTR-66G from the 1960s:

Other spherical sets in my collection include the Trophy baseball radio, Weltron 2001 "space ball" radio, and JVC Videosphere television:

     

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