<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:10pt"><div>Hi Larry,<br><br>It has been a while since I built my LPU but I remember
the assembly procedure for the regulators and heatsinks well. You are
correct the heatsinks are soldered to the PCB. The assembly sequence is
to 1) Apply a small amount of thermal compound, (CPU heatsink compound
or 20% zinc oxide compound from the pharmacy) to the back of each of the
regulators 2) Attach the regulators to the heatsinks with the provided
hardware. In order to make the alignment and soldering of the regulator
pins easier, do not tighten the hardware. 3) Align the regulator pins
and the heatsink pins with the holes in the PCB. 4) Solder the
heatsinks to the PCB. Hint: If you don't have an assistant to hold the
parts in place, wind three or four turns of solder wire around a pair of
needle nose
pliers with a diameter large enough to fit over the heatsink pin. 5)
Solder the regulator pins to the PCB. 6) Tighten the hardware.<br><br>The
only caveat is to make sure you put each regulator / heatsink in the
correct position on the board. It is easy to mess this up and almost
impossible to fix.<br><br>One other suggestion based on my experience.
There is some freedom of movement with the positioning of the ATX
connector. Make sure that you don't inadvertently cover the through hole on the
PCB for one of the leads of the large ceramic resistor with the edge of
that connector. <br><br>73,<br><br>Dan N4XWE<br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Larry Gadallah <lgadallah@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> hpsdr@openhpsdr.org<br><b><span style="font-weight: bold;">Sent:</span></b> Sat, December 4, 2010 5:39:55 PM<br><b><span style="font-weight: bold;">Subject:</span></b> [hpsdr] Noob LPU question<br></font><br>
***** High Performance Software Defined Radio Discussion List *****<br><br>Hi all:<div><br></div><div>I'm in the midst of building my first LPU, and the instructions direct me to bolt the regulators to the heat sinks and then to bolt the heat sinks to the PCB using the supplied nuts and the studs on the bottom of the heat sinks. Only thing is: There are no supplied nuts, and the studs on the heat sinks are not threaded. In fact, they look like they are tinned and hence indented to be _soldered_ on to the PCB. Is this the case, or do I have some defective parts?</div>
<div><br></div><div>Thanks es 73,<br>-- <br>Larry Gadallah, VE6VQ/W7 lgadallah AT gmail DOT com<br>PGP Sig: 917E DDB7 C911 9EC1 0CD9 C06B 06C4 835F 0BB8 7336<br>
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