Component Assembly of the Micro908 Kit
Some folks in this initial deployment of the
Micro908 Kit have expressed doubts about their ability to successfully
assemble the surface mount technology (SMT) components used on the circuit
board. In order to shed a little light on what really lies ahead, I'll
discuss the extent of SMT used in the kit and you can perhaps better determine
your own need for assist in assembly.
Further, I've placed onto our Micro908 project
page an advance copy of an article I did for HOMEBREWER Magazine #3. It's
called "Working with Surface Mount
Technology" and will hopefully give you all some sense of how easy is
can be - all you need is a couple of common work place tools and a semi-steady
hand. (Please don't share this article around to anyone - it'll be
available to others downstream on the HOMEBREWER CD-ROM.)
First, it's not overly clear from the Micro908
schematic and photos how many SMT components are used. Here's
a component breakdown (numbers are approximate) ...
MAIN BOARD - (option for pre-assembly,
- 47 resistors, 1206 packaging
- 26 capacitors, 1206 packaging
- 7 electrolyic caps, SMT "cans"
- 2 integrated circuits (8-pin and 16-pin),
- Bunches of normal connectors, controls &
DAUGHTERCARD - option for pre-assembly (see below)
- 3 resistors, 1206 packaging
- 1 resistor, 1/4W axial lead
- 8 capacitors, 1206 packaging
- 2 electrolytic caps, SMT "cans"
- 2 inductors, SMT size
- 1 inductor, 1/8W-sized axial lead
- 1 integrate circuit (18-pin), SSOP size
- 1 osc module, 14-pin "DIP" sized
- 1 pinheader connector, 0.1"-spacing
DAUGHTERCARD - comes preassembled, programmed & tested
DSPx DAUGHTERCARD - comes preassembled &
So, you'll see there's really not too
much to worry about. The "1206 packaging" is a piece of cake
to apply, as seen in the photos from the article. The ICs are the only
tricky part, but I've personally had 100% success on all the ones I've ever
attached ... and I have a fairly heavy hand and have used lots of heat on the
leads (and SolderWick) along the way. These little parts are
surprisingly robust. I urge you to give it a try ... we'll have extra
parts and some volunteers downstream to help out if you mess something up
along the way and need some help.
As some of you know, we already have an
arrangement for ownders of the DDS Daughtercard Kit to get the IC attached, or
the whole board assembled, by Mike WA6OUW of KitBuilders, Inc. out in
California. For a very nominal price, Mike does an excellent job of
attaching the component(s). All you need to do is mail him
your kit and DDS chip (freely obtained from Analog Devices) and he mails it
back to you assembled. You still need to put the rest of the project
together and test it out, but you can be assured that the components have been
We're arranging the same deal with KitBuilders for
the Main Board of the Micro908. Mike is currently sizing up two options:
1) just attaching the SMT components (ICs,
resistors, capacitors); and
2) assembling all components, including
controls, display, connectors, et al.
Remember that you'll need to put the rest of
the kit together yourself (install daughtercards, enclosure, batteries, etc.),
as well as test and diagnose any problems. That is, Mike does not
deliver a completed, operation uinit back to you. He just assembles the
components to the circuit board.
In some cases you might wish for someone else to
build and test the whole Micro908 Kit for you. We don't have anything
lined up here, and will likely stay out of this part of the "business".
However, we will advertise on the QRP-L list for others who might wish to perform
this surface and we'll connect you with these volunteers so you
can negotiate price and other details.
to Micro908 Home Page
Page last updated:
April 16, 2004