K2 build project: Parts inventory and control board

Having read a couple of blog posts that other people wrote about assembling K2s, and having read the introduction to Elecraft's wonderful assembly manual, I resolved to take a "measure twice, cut once" approach to building my K2. With that in mind, the first order of business was to do a full parts inventory and make sure nothing was missing.

Elecraft makes this pretty easy by providing all the resistors you need, in order, in tape reel form; putting the parts in separate bags for each phase of construction; and providing a nice appendix inventory of all the parts, with helpful photos, divided up by phase. This almost aligns perfectly with the bags, except that the RF board parts are in two bags, and the inventory doesn't specify which will contain a given part. I just inventoried one bag, then made sure all the remaining unfound parts were in the other.

In the end, I was missing one set of header pins for the control board, and one capacitor for the RF board. A quick email to parts@elecraft.com, and I had the replacements 2 days later. They didn't even impede me from getting started with the construction.

The control board is the first phase of the build, and Elecraft's construction manual proved itself right off the bat. It's just incredibly well-written, clear and unambiguous. It has you install components in groups, and in an order that keeps you from painting yourself into a corner. For example, it starts with all the resistors. The first step is something like, "Install R5 (orng, orng, orng). Bend the leads so they fit through the holes. Mount it with the tolerance stripe down for easy reading later. Solder it and trim the excess leads." Then step two is basically, "Now mount all the other resistors in the following order…" So the first step for a group of parts gives you some tips on working with them and has you start with one, and then subsequent steps walk you through the rest.

The control board construction was pretty straightforward, and I finished it in about 6 hours. Here are some photos that show the board taking shape. You can see high res versions here.

This is my workspace, with all the K2 stuff laid out. Once I got started I cleared away more space so I only had the parts I needed right at hand. On the left is the K2 assembly manual. At center, the Panavise workstation. Center/bottom is RF board for the K2, to be assembled later. On the right, a so-so Weller soldering iron; I later borrowed a Metcal from my friend Nick, which I'll use for the rest of the build. All the stuff in pink bags is K2 parts.


Resistors installed, not yet soldered.


Closeup of resistors after soldering. My joints got cleaner as I went along.


Resistor networks installed. I had never worked with these before.


Small value capacitors, trim pot, and shielded inductor installed. I also flipped the orientation so that the Panavise jaws didn't squash the resistor network on the right side.


Electrolytic caps installed plus bonus artistic depth-of-field shot!


Bipolar transistors installed.


Voltage regulators and crystals.


All done! PIC, various op-amps, and header pins all installed. Everything checks out under test for now; more extensive testing will be done when the front panel board is finished. That's up next!


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