All keyers are not equal

iCW is a system of CW using the internet. I’ve mentioned it before so won’t go into the edtail here, but, I like it and I’m sure others won’t, probably because it uses no RF. My counter to that is Morse didn’t always use RF so what’s the deal? Regardless of your feeling it is easy nowadays to pay little attention to tone as modern rigs have a user definable tone and they are generally a well formed sine wave. This, as I found out, isn’t the case when using external keyers.

I bought a K16 keyer kit from Kanga Kits for next to nothing in today’s terms with the anticipation of connecting it to iCW through the internal soundcard. perhaps using the computer as a kind of filter to keep some of the rough edges away. What resulted in iCW was the ‘sound of sanitation’ as we dubbed it. Basically it is a brilliant keyer and I’d recommend it to anyone but sounded like $hit when on its own. It probably isn’t meant to be used like that though so don’t pay too much attention to that.

Next up was a filter using the Sotabeams DSP audio filter, let’s not assume that I am using this as its intended purpose but there could be some mileage in having a play and seeing what happed. There was an improvement but not as much as the audio output from a rig. So to continue the sewage based analogy the attempt at polishing the turd succeeded only in rolling it in glitter.

Last up was the more elegant solution. A handy filter called the Hi-Per Mite. For the lazy it makes the squarish wave that comes out to the K16 a little more sine like. For the intrigued a greater explanation is available at the place where you can buy these, the 4 States QRP Club.

The audio samples and graphs go to show that with a relatively small interaction a filter is all you need to prevent your calls be ignored for any number of reasons except for perfect tone. I would be pleased if the two components could be easily integrated as not only an exceptionally competent keyer but also practice oscillator.


I wasn’t ure what I was seeing here. Apart from the fact that the tone is enough to make you want to turn it off!

Ah thats better…Just one signal and pleasureable to listen to as well

So, what have I learnt this time?

The K16 Keyer is excellent but needs some help to make it sound nice. The Hi-Per Mite filter is just the companion it needs.

Alex Hill, G7KSE, is a regular contributor to and writes from Cumbria, UK. Contact him at [email protected].

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