Junghans J28, updated 14.06.2023 - Helicopters, pocket watches, flight simulation, tools.

Timing Watch

J28 1955 - 1962

628 1962 - 1989

Open face

28, 28/1, 28/2, 28/11, 28/20,

628.00, 628.01, 628.02, 628.11

19'''

48,8 mm

10,0 mm

1/10 sec. = 36000 A/h

1/100 sec. = 360000 A/H

W1819

F.W.S 1972 page 111

55 x 76 mm

101g

The production of the stopwatch began in 1955. In 1962, Junghans decided to rebrand its movements, and the J28 movement was given a new name: 628. Interestingly, a letter dated April 28, 1958, from Friedrich Emmel to Mr. von Zeppelin indicates that the development of the J28 had actually commenced well in advance of that date.

The development of the J28 timing watch movement can be traced back to a significant milestone in 1933 when Hans Schlenker filed a patent, #DE597698. In 1935, Junghans was presented with the opportunity to acquire the patent from Hans Schlenker, but they declined. However, in 1937, Hans Schlenker presented an exemplary watch. It wasn't until 1945 when Hans Schlenker joined Junghans as an employee that he became the specialist for timing watches. Finally, after another 10 years of refinement and development, the J28 movement was ready for production. DGC Mitteilungen Nr. 174

These captivating images showcasing the Junghans J28/20 "Worktimer" timing watch have been graciously provided by the Deutsches Uhrenmuseum Furtwangen. Notably, this particular variant of the J28 was conceived by the innovative mind of Hans Schlenker and even secured a patent in the United States in 1960 under the number US3077729. It is fascinating to note that this extraordinary timepiece stands as a unique and exclusive specimen, as it never entered production.

Accurate recording of single processes.

Presision movement with jewelled pallets, 7 or 15 jewels, Balance shockprotected, Nivarox hairspring, antimagentic and independent of temperature variations, barrel with maltese cross stop work, unbreakable mainspring. Balance oscillations are transmitted directly to the 1/10 seconds recording hand, thereby eliminating inaccuracies.

Particularly reliable through hardened steel components and breakproof springs.

Chromium-plated metal case, 55 mm diameter, protected against spray water.

Sprayed white metal dial with three seperate, graduated circles for minutes, seconds and thenth of a second.

60 minutes.

The watch is supplied in a handy artificial leather pouch.

Starting, stopping and return to zero controlled by pressing crown. The stop watch is wound by turning the knurled crown.

Reading made easier by three seperate dials. Hands cannot stop on top of each other. Reading more accurate as reading marks are distinctly spaced and the 1/10 seconds hand always stops exactly on a mark.

Greater accuracy. Each oscillation of the balance is recorded by a distinctly perceptible move of the 1/10 seconds hand. Zero-setting faults and dial faults which influence the timing result are eliminated.

The 1/10 seconds variant with 15 jewels were also available as "Officially tested "Meister" stop watch" with engraved number on the outside of the back. This watch has been tested by the "Physikalisch-Technische Bundesanstalt" and is delivered with a official certificate. Chromium-plated metal case, 55 mm in diameter, spray-water protected, precision jewlled lever movement, 15 jewels, gold-plated plates, shock-resistant, anti-magentic Nivarox balance-spring which is independent of temperature variations, unbreakable mainspring. Construction and performance of the "Meister" stop watch guarantee a timing accuracy which fullfills the requirements demanded by international contest regulations for the recognition of championship records.