In Dronningborg combines, only two threshing drum widths were used for a long time: 112 cm and 140 cm. The first model equipped with the wider version was the D-2500 introduced at the end of the 1960s, which was powered by a turbocharged six-cylinder Perkins engine. As a smaller alternative, the D-2200 was introduced in 1971, featuring a 6.1-liter Perkins engine without a turbocharger. Both models had a hydrostatic drive transmission, controlled by a hand lever. The diameters of the threshing drums were 50 cm in the smaller model and 57.5 cm in the larger one. There were also differences in the length of the threshing bars and the size of the sieves. Hydraulic unloading of the grain tank was standard.

In the mid-1970s, the updated models D-2250 and D-2600 were introduced, the latter receiving a 206-horsepower V8 Perkins engine. The maximum cutting width was 677 cm. The grain tanks were larger than before, and a factory-installed cab was available. In 1977, the D-1900 was introduced at the lower end of the range, equipped with the 140-cm threshing mechanism, with a slightly smaller threshing drum diameter once again.

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