Junghans 667.70

Description

1978, the reworked versions of the caliber series 667 were launched, among them the 12 ligne caliber Junghans 667.70 with a date indication.

Compared to the predecessor series, there a a few savings, like two bearing jewels on the base plate, which were not visible, and were transformed into brass bearings.

The large rotor bearing jewel and the jewel for the first reduction wheel were not changed, as well as the fact, that the gear train is housed in a plastic container.

There’s a new hacking function, realized by a silver-colored lever near the center of the movement.

The gear train itself remained the same and consists of the center minute wheel, which is beared below the plastic container, the third wheel, seconds wheel, reduction wheel and finally the rotor.

The center seconds pinion is driven indirectly by the third wheel and a tiny spring ensures, that it doesn’t flutter.

One of the most visible changes is the coil, which has got now a thicker, cyan-colored insulation. Maybe it’s because of the coils of the earlier caliber series being too delicate?

The electronics part was reworked, too. The circuit board is now red instead of green before, and a new IC was used.

The basic structure of the electronics module remained the same during the whole series production era and consists of an IC (unlike the predecessor no longer made by NEC, but by the Munich semiconductor producer Eurosil), a capacitor, a trimmer capacitor and a 32 kHz quartz.

On the lower side of the module, there’s the contact for the hacking lever.

The calendar mechanism uses plastic parts everywhere, for the hour wheel, the switching wheel and the detent lever.

The Junghans 677.70 offers a quickset mechanism for the calendar, realized by a rocking-bar “winding” mechanism, in its middle position.

The calendar mechanism is plastic-covered, too.

Technical data

Usage gallery