[Elecraft] K3 - SMT mods

[Brian Lloyd]

> I am in no great hurry to do any mods, since the lack of them is not  
> making
> any noticeable difference to my K3. My concern is that when trying  
> to use
> the desoldering braid, enough solder will remain to keep the part in  
> place,
> and one will end up doing it too many times and eventually lifting a  
> trace.
> One list member already reported doing that.
>
> I don't have any scrap boards with SMD components to experiment on,  
> but
> since all that is needed is to remove a couple of parts, I planned  
> to try
> this:

Instead of "trying" things, why not use the tools that professionals  
use? It just isn't that hard nor is it all that expensive. My  
temperature-controlled hot-air gun just wasn't all that expensive.

> Using a bit of stiff copper wire, wind a tight coil of 2 or 3 turns  
> so that
> it is a tight fit on the end of the soldering iron bit, and turn the  
> ends of
> the coil so that I end up with a bit with two prongs extending  
> forward of it
> for a few mm, spaced apart by the width of the SMD part.
>
> When the iron is heated up, it will heat the copper wire extension  
> as well.
> I will then apply the bit so that the wire prongs are either side of  
> the
> part to be removed. The idea is that the solder will be melted on  
> both sides
> of the SMD part simultaneously and the part can immediately be  
> moved. If
> necessary, the solder wick can then be used to clean up the area.
>
> Does anyone think this would work?

It might, and it might damage the board. I guarantee the hot-air gun  
will work better and be less prone to damage.

And temperature control is important. Using a 500C hot-air gun is  
going to burn up your board. I can set the air temp on mine to 250C to  
melt the solder without frying the board.

Look at it this way too: if you are building things you are going to  
start using SMT. So get the right tool before you ruin something.

--

73 de Brian, WB6RQN
Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com