An iambic keyer in 5 minutes

When most people think about a telegraph key, a piece of 1890s tech with a lever that moves up and down comes to mind. These ‘straight keys’ were terrible for telegraphers and led to repetitive stress injuries like carpel tunnel syndrome..Iambic keys came along and move the contacts to a horizontal position. If you ever see a HAM playing with his CW rig, chances are they’re using an iambic key. It’s great, then, that you can build your own iambic key in five minutes using parts you have lying around.

The build [Dimitris] put up is dead simple – just two metal contacts with a pair of 470K pullup resistors. All this connects to three pins on an Arduino. All the micocontroller needs to do is measure the rise time a touch sensor pin when a voltage is applied. If there’s a finger on the pin, the capacitance increases and the rise time is longer. After that, just assign one sensor as ‘dit’ and the other as ‘dah’ and you’ve got an iambic key.

[Dimitris] put all the code for his project up on his blog. His iambic key seems like the perfect project after a tiny Morse trainer. Check out the video of the key in action after the break

Comments

  1. sawo says:

    Carpal Tunnel Syndrome, not Carpel…

  2. brad says:

    The CTD Risk Index (cumulative trauma disorder for those of you not in the biz) looks at a variety of repetitive motions, and a horizontal pinch can be just as damaging as other motions. Yes, there isn’t as much impact to your fingers with this build, but making repetetive movements has potenital to injure no matter what you’re doing.

    Neat build though.

  3. Peter says:

    Shades of the past!

    I used to have a Heathkit keyer like this:

  4. DonB says:

    You can do the same thing with a TI Lauchpad: http://dbindner.freeshell.org/msp430/cw.html

  5. Tom the Brat says:

    Tried learning CW in High School, but couldn’t pass the test ’cause I couldn’t send with a key. I could with a “bug” which was the mechanical version of that dealy.

    “Dad,” my younger son once said, “you have the coordination of a philodendron.”

  6. N0LKK says:

    So where is the rig interface? Without that it’s not a keyer. And BTW what does HAM stand for? ;)

    • Scuzz says:

      HAM doesn’t stand for anything. It was originally used to refer to the fact that amateur radio users would stomp all over everyone else’s signals and were considered “ham-fisted” (or so I’ve been lead to believe).

      You can read a similarly condensed history here: http://www.arrl.org/ham-radio-history

      • n0lkk says:

        The question was posted in friendly sarcastic manner. I have pointed our several times simply ham suffices for the common nick name for amateur radio operators and HAM is not an acronym for anything related to amateur radio, as far as I know anyway [shrug]

  7. therian says:

    sadly CW keys is only thing that HAMs are building nowadays

  8. Macak says:

    Can you made anything simple without Arduino, eeproms, processors? I has keyer long time before this. Kids will need PC to light a fire in the fireplace.

    • n0lkk says:

      Yea, yea.. we all read that before. :) Most use methods other than flint or friction methods to light the fire place these days. Computer used electron tubes. Time move on my friend

  9. PP5VX (Bone) says:

    Wow ! I got my ticket 38 yrs ago here in Brazil.
    I love speedy CW using my ears (two – of course…hi) and loved this one !
    Boy ! When I become CW fan at 17 yrs old I do it with a “Sideswiper” thing because of speed…
    ( search on Google abt it ), and today in LESS THAN 5 MINUTES I got high speed right from the box !

    73/DX and
    See Ya on the Bands (all of them !),
    PP5VX (Bone)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 97,511 other followers