Before making a radical change to the PA transistor (BS170s) thermal design it is necessary to fully understand the the thermal parameters.? As Hans ha pointed out:
- The six layer board conducts heat very well and is designed with lots of copper in each of its layers.? You may of noticed how much harder, time/temperature, it is to solder parts than the QCX and QDX kits.
- Under the flat surface of the BS170s is a large heat sinking layer.
Background:
? ?BS170 Thermal Resistance
?220C/W??(package only)
175
°
C
/
W
?(plated through-holes)
145
°
C
/
W
?(plated through-holes and?
0.25
i
n
c
h
2
?pad per lead)
