Semi-automatic Speed Key ca.1949-54
A futuristic ‘bug’ key which failed to draw hams away from the traditional American ‘open’ bug key.
Its history is surrounded by controversy. It has been well aired in ‘Morsum Magnificat’ magazine.
Price in 1949 £3 , 1954: £4 .
The key is almost entirely constructed of untreated brass and die cast aluminum, the base and cover being finished in the then almost obligatory black crackle or wrinkle paint. Despite the base and cover being aluminum, the weight of 2 lb. 14 oz. (1.304 kg) is adequate for most operators, although fixing holes are provided in the base.
The majority of adjustments are carried out in a similar manner to most other conventional single lever semi-automatic keys. The exception to this is the dot return coil spring, the tension of which is not independently adjustable. This spring is held by the left-hand control arm stop screw and the tension can only be varied to a small degree by setting of both the left-hand and the right-hand stop screws.
The main pivot pin bearings consist of a single ball for each bearing, only the lower of which is adjustable. Two speed weights are provided, one large and one small, and use of either or both can give a wide variation in dot speed. The arm is damped in the rest position by a rubber grommet on the back stop. This is remarkably effective in use, although the rubber does become brittle with age.
Why the Eddystone S689 proved to be so unpopular is unclear. Whilst admitting that the general feel of the key does fall somewhat short of the many excellent American high speed semi-automatics, the key does not suffer from any major defect in design. The combination of a number of its shortcomings may, however, have been a contributory factor to its unpopularity.
The exact number of S689s produced is unknown, but it seems clear that the figure did not exceed 500.
No serial plates were fitted to the keys. A number is stamped on a connecting strip on the underside of the base.
