Top Panel Vibration Analysis; Lift-Up Mechanism Of The Front Bases - Kenwood TS-990S In-Depth Manual

09 TECHANICAL STRUCTURE

Top Panel Vibration Analysis

The TS‑990S cabinet has been designed by taking into account, the sound quality of the internal speaker.
Through CAE analysis for the chassis‑enclosing cabinet, the screws are placed in a manner such that they will
minimize deterioration of the sound quality. In addition, with conjuncture on the locations of the nodes and anti‑nodes
of vibrations by frequency through vibration analysis of the cabinet, the screws are placed to suppress vibrations. The
screw placement serves to prevent the deterioration of sound quality due to the mechanical structure and achieve better
listening ability even during long operations.
Fig. 8 Simulation of Top Case Deformation
The island‑like portions are anti‑nodes where the top case is expected to be deformed to the convex or concave shape
against the audio in a certain frequency. The other portions are nodes where no vibration occurs. Sound from the
speaker causes the top case to resonate and deform, and the sound from the speaker is mixed with noise emitted by the
cabinet due to the vibration, resulting in deterioration of the audible sound. To suppress the deformation, the locations of
the deformations (anti‑nodes) need to be secured with screws.
The screws, which are not symmetrically placed, represent the deliberate design of the transceiver with a built‑in
speaker, in which each screw is carefully located.
Lift‑up Mechanism of the Front Bases
For the lift‑up mechanism of the front bases, rotary levers are used to allow the extensions to be easily folded and
unfolded.
When the extensions are folded, they are invisible from the front without detracting from the esthetic design of the front
bases. When the body is lifted up with the extensions, the shapes of the front bases and extensions match in the form of
an arc with a look of a unified and beautiful appearance.
Fig. 6
96
Extensions Folded
Fig. 5 Screw Placement on the Top Case
Same Circle
Arc
Fig. 7 Extensions Unfolded
Lift-up