Intro |
Well, the gang at Norcal have come up with another one! Later this year, they plan to introduce a 10 meter rig using surface mount parts. To get us all warmed up for it, they came up with this little 40 meter job so we can get some practice with the tiny parts. This is called the SMK-1 and you can see the whole story by clicking on the link. Also see Red Hot Radio's page. Basically, the rig is a Tuna-Tin 2 plus MRX on a single board but built with surface mount parts. Thankfully, they used the large, 1206 parts where there was a choice. Just today I took a peek inside my new 2800H, and they used some 1206's where they needed the power capability - they are absolutely huge compared to the 0403's.
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Building the Kit |
Wow - building this radio is a whole new experience. The parts are really tiny, and my soldering iron is truly huge. It took quite a bit of care to get those tiny parts soldered down where they belonged, but in the end it worked fine with no problems. I used 2 different techniques, described in various other pages. For the parts with 2 connections on opposite ends, I basically pushed the part into a pool of molten solder on one pad. With the part held in place I could now (more or less) easily solder the other end. For multilegged parts, I used a surface mount holder-downer built from a dowel, coathanger and fishing weight following the lead of many others who built similar devices. With the part held in place both hands are free for soldering. In spite of the huge size of all my soldering iron tips, only the SOT-8's required that I resort to extending the tip with a piece of wire. (Why on earth does a 78L06 come in an 8 legged package?) I kept my iron at the recommended 700 degrees F, but I had the feeling it was too warm. Also, I used silver solder as suggested.
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Opening the Kit |
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Opening the Kit |
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Bag #1 |
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Circuit Board | |||
Parts |
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End of Bag #1 | |||
End of Bag #2 | |||
Completed Kit | |||
27 Dec 2004