(click on images for full size)

OK, tonight I used the Cash Olsen’s SMT Hot Air Method (SMarT HAMethod) to assemble a NorCal Tuner Upper SMT kit for 30 meters. This was my first foray into using solder paste and a hot air tool (instead of the normal soldering iron and spool of solder) to quickly mount the many tiny parts. Using this method, even the first time, I believe I had quite a success and did it in a fraction of the time. Each solder joint is clean and even. The components really do center (mostly) on their pads.

As a pre-warming surface, I picked-up a 12″X12″ Rival electric skillet from Target for $24.99. I could have spent less but I wanted a surface that was large enough for most any circuit boards and have raised walls to safeguard against parts getting lost. The skillet has a WARM setting which sits at a nice and even 200 degrees Fahrenheit at the surface. My Multimeter has a temperature probe that is accurate enough for this application. I actually put the SMT parts on the board right in the skillet (before I turn on the heat silly!). This skillet also has a cover which I can put on when I need to take a break (you know, like going to get another cold beer hi hi).

It was a simple matter of dropping a small dollop of solder paste, which I ordered from Electronic Research Group. The Kester paste comes in larger quantities but it is WAY more than most of us need in the shack and it does have a shelf life. The paste needs to be stored in the fridge. I hardly noticed any difference between the amount I had when I started and how much was left in the syringe afterward. So there should be enough for plenty projects in each of these syringes.

Having never done this before, I wasn’t sure how long to hold the heat tool on any one spot. So I just ran quick small circles across the surface of the board. About three minutes after I began, I noticed the paste turn from its dull grey to a nice shiny silvery sheen. You’ll see the components pull toward the center of the pads as the paste melts. The following images show, from left to right: 1) SMT components mounted on the circuit board mushed onto a dollop of solder paste 2) first round on the board 3) second round to get the two less-than perfect points 4) final results:

The images above show the circuit board in the tin.

Earlier this year, I built this same kit for 20 meters. It took me the better part of a morning to solder each of those parts to their pads. There are just a couple through-hole parts in this kit. The main time sink is winding the toroids. I suggest using a chopstick in a vice to hold your toroid between each winding. The results were nowhere as neat and clean as what I get using the SMT Hot Air Method. Never mind the fact that this took less than half an hour to mount the SMT parts, I’m going to start calling this the “SMarT HAMethod”.

SMarT HAM above, Done By Hand below.

Here’s a video I found on YouTube that shows how the pros do it: