K2 build project: Front panel

Sorry for not updating again sooner, I've been making steady progress on the K2 but, when faced with the choice between spending an hour writing a blog post or an hour working on the K2, the K2 wins!

The front panel went together very easily, both because it has fewer parts than the control board, and also because my rusty soldering skills have gotten back up to par (at least by my standards). Now, a couple of weeks in, when I look at the control board I'm a little disappointed. That row of transistors doesn't have a uniform height! But Nick, my EE buddy, inspected my work and gave it a thumbs up, so that's a good sign.

The front panel consists of all the buttons and knobs, headphone and mic jacks, the LCD screen, and the S-meter. The LCD is actually pretty tricky to install. I'm not sure if this is common or what, but the LCD and the backlight were totally separate units. The backlight consists of two LEDs at either end of a glass diffuser with a special paper over it to help diffuse the light. You mount this first, on its LED leads, using spacers made out of scrap PCB so it stands off the main circuit board by 1/8". Then the LCD straddles the backlight, and you solder all its pins afterward. It took me quite a bit of careful assembly to get these right, but I knew I needed to take my time to avoid having a sub-par display.

The rotary encoder which makes up the brains of the tuning knob is pretty neat. I mean the encoder itself is nothing special, but Elecraft gives you a felt washer that goes around the tuner's axle, between the plastic knob and the front panel itself. This is to provide some friction against the knob so that when you spin it it doesn't keep spinning forever. Love the attention to detail! And now, some photos:

First we install the buttons.


Mic jack, S-meter, socket (on back), various microcontrollers and other components.


My wife took this one of me soldering.


Trim pots, LCD and backlight, and key caps added.


Everything mounted in the front panel casing! I definitely spent a few minutes turning knobs and pushing buttons and making CW sounds after reaching this point. I'm not gonna lie. The RF board is next!



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