Originally an innovative telephone, with a few original design solutions. It was the succecor to the famous Bauhaus telephone, also known as the model Frankfort. It often has the same handset, designed by Marcel Breuer. It never was accepted as a standard model by the Reichspost. It was therefor sold to private companies.
This family consisted of 4 basic models, the Maingau 34, 35, 38 and 46. The numbers indicate the year of introduction. These phones come with a variety of dials and handsets. Determining which model you have, can only be done by looking at the inside lay out of the components and the kind of ringer used. If present, the earthing button can also be indication of the specific version at hand.
The Maingau 34 has a panel inside the body shell, which separates the shell in an upper and lower compartment. Electrical components are mounted on the under and upper side of the panel. It has a small ringer, with 2 concentric bells. It has a small grey earthing button (or none at all), in the middle of the phone, just in front of the dial.
The Maingau 35 has the same inside panel, but the ringer has 2 small oval bells, mounted side by side. If an earthing button is present, it is grey, mushroom shaped and in the same position as with the Maingau 34.
The Maingau 38 (pictured) has a more conventional lay out, with all components mounted on the base plate, with 2 small round bells underneath the strip with terminals. If an earthing button is present, it is positioned off side to the right and coloured black.
The Maingau 46 has a conventional lay-out and a higher body shell. Bells side by side at the front, ringer mechanism in the middle, capacitor to the right, speaking coil at the back and terminal block at the left. The earthing button is in the middle and black.