DSP-610 ~ Fabricating the PA Heat Sink

Sinking In..

 Poking around in the local surplus store last weekend, I found this roughly 4" x 6" 16-fin heat sink in a bin called "scrap aluminum"!

With out even measuring the part I put down the $2 and brought it back to the ranch,  As you can see a near perfect fit!  I am not sure this will provide adequate cooling or even how I plan to mount it in the chassis but it is a start to the power amp build for the DSP-610

 

 

 

For Good Measure

It would be too much to ask that any holes on this part would be usable.. and this was the case.  I think this was from a power supply or battery charger of some sort...probably a military device. I used the DSP external PA PCB to mark the locations of the required holes.  The trick was to find free of holes, or not too close anyway.

 

After studying the data sheet it looks as if the pin outs for the board intended the TO-220  transistors, to be mounted under the board.  Which works out that the heat sink (or chassis) will work under the circuit board.



 

This also explains the over sized holes...  The screws holes were drilled an tapped to accept #4-40 hardware.  Access through the holes will allow easy mounting to the sink. 

 

 

 

 

These spacers were only for test fit, the final hardware was #4-40 1/4" hex M-F standoffs, which will reduce the lead length,  The bends for the leads may be  a little tricky as I did not get the mounting holes exactly centered...but it should work out OK.

 



 

A dab of heat sink compound on each, and I think this will work!

 

 

READY TO BUILD...

The board seems to have found a good home!  I hope the mounting in the chassis will be OK and this assembly will dissipate the required heat for the RF  power transistors.