Tait TM8000 Series, Service Manual

Page: 45 / 244

TM8100 Mobile Radio Service Manual General Description 45
May 2004 © Tait Electronics Limited
Dissipation of Heat
Heat needs to be dissipated from the interior of the radio body and, in
particular, from the following components on the main board:
■
9 V regulator
■
audio PA (power amplifier)
■
two RF PAs
■
driver for RF PAs
These components are discussed in Section 3 . The mechanisms by
which the heat is conducted away in each case are described below.
Dissipation of Heat
from Radio Interior
Heat from the radio interior is conducted via the heat-transfer block to
the cooling fins at the rear, where it is radiated away. The ridged
underside of the chassis augments the dissipation of heat. The rear face
of the block is in contact with the chassis where the fins are situated. A
coating of thermal paste on the rear face ensures the necessary thermal
contact between the two surfaces. The coated area is shown in both
Figure 2.11 and Figure 2.12 .
Figure 2.9 Parts of the lid assembly
5
6
7