K8 – PIC-based electronic morse keyer

K8 – PIC-based electronic morse keyer

Posted on October 21st, 2005 in Hobbies, Amateur radio, Electronics.

Kindly offered to the ham community as freeware, the K8 keyer by K1EL is an iambic keyer, embedded as software in a PIC chip. Its biggest advantages are that it is free (duh!), easy to build and very small.

The best implementation I have seen so far, is from W0PWE. He has circuit diagrams, PCB layouts and much more. The original presentation of this keyer can be found at K1EL’s homepage. You will need a PIC programmer to upload the software. I have one available on my Electronics pages.

The disk with the holes you see on the front of my memory keyer is in fact a small speaker that I salvaged from a set of defective cheap headphones. I found that piezzo speakers only give moderate output at the 800Hz the PIC puts out. I must say the headphones speaker doesn’t do any better, but it’s enough because my rig puts out a sidetone as well, and I have my headphones on anyway…

I run the keyer on a pair of AA batteries, which works very well. The keyer does not need an on/off switch, since the idle current of the PIC is only a few µA’s. I haven’t had to replace the batteries for two years.