WITTNAUER TENOR-DORLY TD1393 COFFIN JUMP HOUR 1975
The coffin-style Wittnauer Jump Hour is one of the coolest designs featuring a robust Tenor-Dorly 1393 calibre. The TD1393 movement is more complicated than an average automatic direct read from the 1970's but the various designs available prove that it must have been pretty popular among watch producers. It was sold under different brands such as Tenor-Dorly, TD, Waltham, Technos, Sempertalis, Dynasty or even the top-shelf Universal Geneve. Gunmetal or blackchrome versions are uncommon and have been very likely custom modified.
The usual problem is a running balance without moving time discs. This is caused by a worn (slipping) friction-wheel (cannon-pinion) press-fitted onto a pinion in the gear train. The movement will continue to run but there will not be enough torque provided to rotate the discs. This will require squeezing the friction-wheel as you would repair any other cannon-pinion for proper friction. Other issues might require adjustments of the springs within the jumping section to create enough pressure on the levers. Occasionally these watches will have broken gears in the jump module if someone had tried to set the time by force on a jammed movement.
Keywords:wittnauer jump hour, tenor dorly,
technos, dynasty
Market value:
80-300$ (non-brand or top-brand, condition, case)