83
MECHANICAL STRUCTURE 11
In order to mount the boards, the interior of the chassis is partitioned in a lunch-box-like layout with the boards secured
in each of the partitions. The lunch-box structure serves to create a shielding effect using the walls of the partitions.
Aluminum die-cast (ADC12) is used to make the chassis so as to achieve a shielding and cooling effect.
Fig. 83
Chassis (Upper Surface)
Fig. 84
Chassis (Bottom Surface)
Cooling
The cooling mechanism is such that heat emitted from the final unit of the TS-890S is directed conveyed to the chassis
underneath, which is then discharged from the back of the cooling fan motor using the fin that is located on the reverse
side of the final unit.
The TS-890S comes with two internal cooling fan motors (80 mm x 80 mm, thickness: 25 mm).
The two cooling fan motors which are installed in front of the final unit and the fin of the chassis not only helps to cool
down the radiating fin, but also prevents the temperature of the parts from rising.
The fan motors can be configured to one of the three operation modes. After countless adjustments of the settings
to minimize the noise during their operation, operation noise of the fan motor has been reduced by at least 5 dB (A)
compared to the TS-990S.
Even if the temperature rises to an unexpected level, a protection function that reduces the transmit power will be
activated to ensure protection against malfunction. The two cooling fan motors are made by Sanyo Denki Co., Ltd.,
which is a manufacturer of highly-reliable products.
Fig. 85
Fan Placement and Ventilation Flow
The image “Fan Placement and Ventilation Flow” shows a visualized air flow in the chassis on its upper side.
