PIK and auto-space

It is more than 10 years since I designed the PIK (PIC Iambic Keyer), a semi automatic Morse keyer (Duffy 2000).

This article looks at the operation of the auto-space feature of PIK.

Origin

The design was motivated by my friend Ray, VK2COX’s desire for a very small keyer to incorporate into a small QRP transmitter.

The design was hatched in my mind riding my motorcycle back from Derby’s Falls (Ray’s home) to my home in Canberra… an hour+ ride.

The design was inspired by the WB4VVF Accu-keyer of decades ago, originally a TTL based keyer. I say inspired because although I did not set out to copy the Accu-keyer logic, I had used one for decades and that experience would inevitably shape the outcome.

The PIK is implemented on an 8 pin PIC chip and uses few external components, hundreds of chips were posted out and an unknown number of PIKs constructed using freely downloaded hex files.

Auto-space

Importantly, the auto-space feature of the Accu-keyer is one that I had grown to not only like, but depend upon. The auto-space feature ensures that characters are not run together, the most common defect in Ham Morse code in my experience.

112

Above is a capture of the DIT and DAH paddes, and the keyer output KEY sending the familiar CQ signal.

Study of the diagram will reveal the benefit of Iambic (B, why would you use anything else) keying. At the highest level, there are 8 DITS and DAHS keyed out, and only four operations of DIT and DAH paddle contacts.

The traces reveal the DIT and DAH element storage of the keyer for relaxed timing of the paddle input.

Now that you are familiar with the display, you will note that the C character starts immediately the DAH paddle is closed, but if look to the Q character, it is delayed slightly from the DAH paddle closure to ensure the correct character spacing (ITU-R M.2004). This is auto-space at work!

Now some Hams hate auto-space, arguing that it gets in the way of sending. It certainly gets in the way of bad sending, if you don’t order up the next DIT or DAH of the current character quickly enough, it will force a character space… you have the speed set too high for your capability at the time! It delays the start of a character if you attempt to start it too early, but you learn to depend on that and start characters a little early for the enforced perfect character spacing… not just automated DITS and DAHS, but automated character spacing.

I have not yet come across the auto-space feature in the internal keyers of transceivers, they offer features to send Morse code that is not standards compliant, like changing weight, but they don’t provide this simple feature that is a great assist to standards compliant Morse code.

References

  • Duffy, O. Nov 2000. PIC Iambic Keyer (PIK). http://owenduffy.net/module/pik/index.htm.
  • ITU-R. 2004. M.1677 International Morse code (2004).