RF Linear Amplifier PCB Assembly Manual
SkyWave DX600 Revision-B
Last Revised - 2/5/2021 9:10 AM
Page 50 of 57
Step #22 - PCB Mounting to Heat Sink
IMPORTANT - NOW THAT THE AMPLIFIER PCB HAS BEEN FULLY ASSEMBLED, IT MUST BE
MOUNTED TO A HEAT SINK BEFORE THE BIAS ADJUSTMENT CAN BE PERFORMED.
A HEAT SINK WITH A MAXIMUM THERMAL RESISTANCE OF 0.75 DEGREES
CENTIGRADE/WATT IS RECOMMENDED FOR CONVECTION APPLICATIONS
§§
.
Position insulators (INSUL1 and INSUL2) on the heat sink so that they will make proper contact
with the metal tabs of Q1 and U1 and will align properly with the tapped mounting holes. Note that
Q5 has no insulator.
Apply thermally conductive paste to the bottom of Q4 and Q6 only.
IMPORTANT
–
DO NOT FORGET TO APPLY THERMALLY CONDUCTIVE PASTE TO Q4 &Q6!
Hover the PCB directly over the mounting holes drilled in the heat sink. Lower the PCB straight
down onto the sink to avoid sliding the insulators.
Install loosely four
5/16” #4
-40 machine screws in the four PCB mounting that have the metal
spacers below the PCB.
Figure 54
§§ There are several internet sites that sell extruded aluminum heat sinks designed for RF power amplifiers. Several are listed below. Telstar Electronics
takes no responsibility for the content of the links and does not endorse any specific product or service.
Communication Concepts
–
www.communication-concepts.com
Heatsink USA
–
