Sunday, April 12, 2015

Elecraft surgery part 3 of 3

Back to life again
It's time to solder in the new P30 and P35 headers into the K3 then put the rig together hold my breath and plug it in! Now that the old headers are out and the solder pads are cleaned off I now want to fit each header into it's spot and see how they fit. Then I will solder them in and it's very important these headers sit flat on the board. Here is the process I use to solder the headers in, I first only solder the 2 outer most pins. This allows me to reheat the pads if the header is not flat on the board if you solder 4 or more pads at once it's very hard to reheat them if you have to reposition the header. Once I am happy the header is sitting properly on the board I then solder the rest of the pins to the board. I
Soldering end pins 
don't solder them one after the other but instead I solder every other pin and then go back and solder the other pins. I do this because the plastic that supports the pins do get hot. I found if you solder one pin after the next the plastic supports have melted on me. Once the top side has been soldered I then turn the board over and solder the bottom solder pads in the same manner. Now that the pins are in I take a break and then come back and take a very close look at the pins. I am looking for proper soldering job,

Imports of checking both sides of board
also there has been no flow of solder from one pad to the next. Finally that I did solder all the pins, I have had this happen in the past were I have missed a pin. This is why I take the break as I have found if I don't I end up seeing what I want and I miss the unsoldered pin because I want to get to the rig put back together and try it. Satisfied with the solder job its time to clean the solder pads and I use a tooth flossing brush with 99% alcohol. This cleans off any residue and the alcohol evaporates. With the new headers installed it's time to put the rig back together and do the smoke test. At this point it's very important to take your time as you put the rig back together. There is the excitement in getting the rig back together and see how it work! This is the time you forget parts, not tighten parts, rush and misalign parts. Great care has to be taken when mating up the new headers. I had all go together well and as you can see from the picture at the top of the post the smoke test went well.
Flossing tool used to clean board
New header lines up with front board. 

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