McDonald was a keen yachtsman and outdoorsman and wished for a portable radio that would provide entertainment broadcasts as well as being able to tune into weather, marine and international shortwave stations too. He asked his company's engineers to develop prototypes to meet his criteria and by 1940 they had concept sets that were ready for production.
The Zenith 'T/O' began life in 1942 as the Model 7G605 'Trans-ocean Clipper'. Priced at $75, it was released in January but ceased production in April as Zenith shifted their production to war-related equipment. During this short production run, some 35,000 units were produced and sales data showed that many were sold to customers in the 'above average' income group. However, many also found their way into various theatres of war and in to the hands of appreciative servicemen—demand for a resumption of production at war's end was kept high.
The first post-war T/O was the 8G005Y, designed by Robert Davol Budlong, an industrial design consultant responsible for many of the Zenith radio products. Priced at $125, it was in production from 1946 to 1949. This was replaced in December 1949 by the G500—a 'changeover' model that had updated electronics but the same appearance. The G500 held its price at less than $100 until it was withdrawn in mid-1951.
The H500 'Super Trans-Oceanic' was introduced in May 1951 at an initial price of $99.95. It had a redesigned front face and incorporated many frequency coverage and electronic changes ordered by McDonald. There also was a small production run of "militarized" Trans-Oceanic's, ordered by the U.S. government.
Eugene McDonald died in 1958, but he was personally involved in the design changes to 'his' radio to the very end. In 1958, Zenith introduced the all-new, transistorized Trans-Oceanic. The older tube-based Trans-Oceanic was continued in production until 1962.
In late 1957 the first of several transistorized Trans-Oceanic's were introduced, the Royal 1000. As had always been the case, Commander E. McDonald helped in the design of the 1000. This was to be his last endeavor in the Trans-Oceanic radio, passing away soon after it's introduction. The Royal 1000 had the exact same frequency coverage as the A/B 600 series tube Trans-Oceanic's with the addition of the 13/meter band. The new Royal 1000 also sported an all metal cabinet design with the front cover opening to the down position. The log chart was located inside the flip-down door. Very early Royal 1000s sported a genuine leather covering marked as such. Another first for portable radios was the unique dial scale used in the 1000 & later series of Trans-Oceanic's. The 1000 was designed with a cylinder dial scale that would rotate with the band switch allowing only that particular band scale to show.
Soon after the introduction of the 1000 model, a second model was added, the Royal 1000D. The only difference was the added LW band covering 150 kHz through 405 kHz just below the AM broadcast band. There were also slight cosmetic differences to distinguish the two models. In "1962" the Royal 3000 was added and the 1000 eliminated while the 1000D remained in production through the 1968 model year. The 3000 added the FM broadcast band and eliminated the 13-meter band. Along with a few cosmetic differences, there wasn't much difference electrically between the new model and earlier 1000 series models.
In 1968 the Royal 7000 series Trans-Oceanic was introduced. The new model sported a completely new look and many improvements over the weaknesses of the earlier 1000/3000 series models. Besides a new look, a BFO was added for SSB/CW reception. Also a wide/narrow filter switch was added for increased selectivity. The 13-meter band was re-introduced along with extended coverage from 1620 kHz through 2000 kHz and the VHF weather band. The electrical design was an improvement in both selectivity and sensitivity. Sound quality was much improved.
The last model Trans-Oceanic was the R7000 series introduced in 1979. This model now had complete coverage from 150 kHz through 30 MHz. Gone was the electrical band spread for improved tuning. The R7000 sported a new electrical design using modular circuit boards instead of the tedious point to point hard wired chassis of all previous models. There were many other new features also such as dual tuning meters, squelch and several added bands such as Air, VHF 144 MHz through 175 MHz. The R7000 was built in Taiwan, while all the models before has been made in the USA.
The new Royal line sold well, but Zenith's lead was steadily eroded. By the time of the release of the 'R7000' in 1979, fierce competition from Sony in Japan—who, with their digital readout tuning dial had, in many ways, a superior product—meant the end of a famous product line.
It is unlikely that this famous family of radios will ever be resurrected though there is a strong following of this most famous series of consumer radio gear. Today the Trans-Oceanic has become a popular radio of both collectors and non-collectors alike.