Posts Tagged ‘keyer’

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.

iCW keyer

Around this time of year the kids finish school for the summer holidays and Mrs g7kse takes them for a week away with her before I get some time off myself. It’s a short break but the house is across the road from the beach and the kids love it. As does Angus (the dog). I then have a week at home / work where the place is a bit quiet. So time to catch up on a few loose ends and perhaps an evening mountain biking before I join them at the weekend.

This time I’m planning on building up the iCW keyer that I have. Well I say have, it’s a blank PCB that Chuck W5UXH was kind enough to give me earlier in the year. I can’t currently use iCW very effectively and my CW is suffering so this is somewhat needed. Now.

The keyer board is the full monty. It has all the bells and whistles and uses a new, to me, fubarino microcontroller. Slightly larger than an Arduino micro and with the provision for an SD card it offers the ability to store ebooks that will form the ability to play dit’s and dah’s as a stand-alone unit. The PCB is slightly larger than I’m used to but is well produced and uses professional parts all available from Mouser. It should take a few hours to build and test, perhaps an uninterrupted evenings work but we’ll see how well that goes and review the time at the end.

In summary….I need to turn this stuff into something useful. Wish me luck!

Morsemail and

The time has come when I can’t put off learning Morse code any longer, With an interest in vintage amateur radio and the impending restoration of a Heathkit AT-1 I’m going to need to use CW sooner or later.

So I have been checking out resources for learning Morse code and stumbled across two that really intrigue me.

The first is, a web browser based Morse code learning tool that is usable on any internet connected computer. It is available free of charge and there is no software to install. keeps track of where you are in your lessons and where you need to concentrate your effort. The Koch method is the primary tool available but they also offer code group practice, callsign and plain text training modes along with a service to convert text to Morse MP3s for download and use offline.

Once you are on the way to CW proficiency and want to communicate with others you can always fire up a rig and get on the air … What if you don’t have a rig or need a confidence boost before ‘going live’?

Well, you could always send Morsemail using the Morsemail client from

Morsemail is, “A simple text format that encodes mark and space times to make it possible to send Morse coded messages via email” but a recently added feature allows for QSOs using a internet repeater hosted on You can use a mouse or actual key wired to the mouse or joystick buttons to send CW which can be emailed or sent through the repeater live.

Now I just have to carve out the time to sit down and use these resources!

Hellschreiber and microprocessors – Bridging more than 80 years

ZL1HIT (Bryan Rentoul) has bridged a gap of more than 80 years by combining the text transmission system developed by Rudolf Hell in the late 1920’s with current microprocessor technology.

A sample of received Hellschreiber test from Bryan’s beacon

Hellschreiber sends a line of text as a series of vertical columns. Each column is broken down vertically into a series of pixels, normally using a 7 by 7 pixel grid to represent characters. The data for a line is then sent as a series of on-off signals to the receiver, using a variety of formats depending on the medium, but normally at a rate of 112.5 baud.

This process was historically accomplished with mechanical equipment but there are very few examples of this equipment still in operation and it is now sent and received by computer. Hellschreiber is very tolerant of noise and interference and requires only simple transmitters and receivers to work effectively.

German Hellschreiber unit in operation

With a microprocessor generating the digital on-off signals a simple crystal oscillator transmitter can be used to form a beacon station, one that transmits a call sign and perhaps some other information over and over. Changing the transmitted message is as simple as reprogramming the microprocessor or having it respond to a connected input, for Eg. A thermometer, light sensor, switch, etc.

Receiving the signal and decoding requires a radio receiver capable of CW reception and a computer running any of several free software packages like FLdigi or Digital Master 780.

The ZL1HIT beacon using a PIC microprocessor and a simple crystal oscillator transmitter.

For more information and the PIC microprocessor source code please visit the web page of Bryan Rentoul here : ZL1HIT Hellschreiber / PIC Beacon

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