K8 KEYER

I finally found myself with time on my hands during a wet winter afternoon, to be able to build Steven Elliott's, K1EL, K8 keyer. Steven has a variety of keyers available from his website. The K8 is based on a small 8 pin PIC chip and although it's the most basic of the K1EL keyers it does have some very neat features crammed into its tiny program memory. The program code can be freely downloaded from the K1EL website if you choose to roll your own... thanks Steve!

Construction: Well it couldn't be simpler! All the components were found in my junkbox and the /JW (EPROM) version of the 12C509 was actually used. I put everything, including three 'AA' batteries, switch and sockets inside a small box and still had loads of room to spare. The batteries should last ages as current consumption when the unit's not being used is virtually nil (the pic 'sleeps'). The circuit's so simple that there's really no need to design a dedicated pcb - just use a one inch square of stripboard. Unless, of course, you want to make it smaller for incorporating into the base of a paddle or inside a homebrew QRP rig!

Features: Five predefined messages with variants for contest and QRP operation. A fifteen character memory to personalise a message for such things as name/QTH or QSL info details. A callsign memory allows for other calls (ex: special events) since the main call is burnt permanently into the program code. Optional sidetone available. The K8 also allows either Iambic A or B modes, character autospacing and a practice mode for brushing up your cw. A push-button is used to have the keyer send the currently selected message or have it accept commands via the paddles.

Conclusion: Overall keying performance is good. Although not as smooth as the CMOS Super Keyer 3, you quickly get used to its 'feel'. The K8 is a worthwhile addition to any shack as a standby or heck... even main keyer. Because it's so small, it's easy to take along as a backup keyer to any dxpedition or special event. For the newcomer who's looking to make the transition from a straight key to paddles this keyer is ideal - cheap, easy to build, good keying and a practice mode for getting your cw speed up - wow... that would make a great ham club or cw class project!

 

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