Thursday, April 5, 2012

K1EL K12 Keyer

Finished K1EL Keyer with Ancient HamKey
HK-1 Iambic paddles.
My 30+ year old CMOS Keyer gave up the ghost -- the point-to-point wiring apparently was suffering from a failure. I tried re-building it using wire-wrap, but the troubleshooting was taking too long. I figured I needed to quickly build a replacement keyer that I can use right now with my TS430S.

I remembered that Curtiss used to make a keyer chip. But a quick search found that the original Curtiss devices were no longer available, although MFJ purchased the rights and offers a slightly updated chip.

Honestly, at the time I looked at this, the chip was $45, which seemed way more than I wanted to spend on a "temporary" keyer. A bit more searching brought me to K1EL's web page.

K12-BAT kit, as it comes from K1EL.
K1EL offers a number of interesting devices and components. The WinKeyer I had heard of -- but frankly, the name put me off slightly, as I've been a long-time Macintosh fan. Imagine my surprise to discover there's nothing "Windows" about the WinKeyer. It looks like a superior product for providing CW keying facilities in a contest station.

But that would be a project for another day. Today, I just needed a simple keyer. And I found it. The K1EL K12 keyer chip filled the bill nicely, and had 6 programmable memories and a host of other features to boot. All for less than $10!

Even better, there was a kit -- only $17. I quickly ordered the K12-BAT and within the week had the package pictured above.

There's not even two dozen components.
There's not a whole lot to the kit -- printed circuit board, socket and chip, transistor, battery holder, and a handful of resistors and capacitors. This would not be a bad first kit for someone. For me, it took less than 30 minutes to assemble.

Finished circuit board.
Once assembled, I wired up the paddles and tried it out. The command structure takes a bit of getting used to -- it's hard to remember for some of the longer commands what comes when.

However, it is quite a serviceable keyer. But, I can't just have wires strewn all over the bench. (Well, actually, I can, but that's not how I like to operate) Digging through my junk box I found a used cast aluminum box that might make a decent cabinet. The hard question was -- what to use for the seven pushbutton switches I needed? Nothing I had in the junk box was small enough to fit in the aluminum box.

Wiring was easy.
The upcoming Dalton hamfest provided the answer. If found some surplus switches that were small enough to fit, and they were cheap, so I bought eight. A subminiature potentiometer filled out the required parts list.

Drilling out the enclosure took a more time than building the board. But the wiring was very straightforward.

All done but the hard part.
At this point, I had a functional keyer in a rather ugly enclosure. Finishing the enclosure took more effort. Removing the board switches and pot left me with an empty enclosure. You can see that it had some kind of adhesive on the top, as well as a bit of corrosion here and there.

The best treatment, I've found, for stout aluminum like this is wire brushing. The oxide and other compounds come off easily, and the steel bristles of the wire wheel score the aluminum just enough to give it a nice texture. Best not to do it in a hurry and don't use too much pressure. I did both and ended up with some deep scratches in the top and a wire-brushed left index finger.

Of course, I had to wire brush it again. I painted the enclosure with the same flat black paint I used to repair the R7000. The end result is pretty sweet.

I'm still trying to figure out how to use the K1EL K12 keyer. In trying to program one of the memories, I have found it is very, very sensitive to character timing. I probably need to read the manual again. In any case, I am very happy with the K1EL K12 Keyer kit. I would highly recommend it to anyone who needs a sophisticated, yet inexpensive keyer.

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