My first homebrew key

Discussion in 'Homebrew and Kit Projects' started by KD2NOM, Dec 22, 2017.

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  1. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    My first homebrew key.

    I have been messing around with the idea of home brewing a key to use with my Yaesu FT-450D and it's built in keyer. After much searching and contemplation, I found the plans for the 'Depot Cootie Key' on Michael Maynard's (K4ICY) website (

    Seeing as I had the day off, I went to Lowes (guess mine will be called the 'Lowe Cootie Key') to get the necessary parts.

    Following the exploded diagram on Michael's page, I quickly put together my key and was able to test it on the air in less than an hour. Mine is made from a left over piece of cedar wood that I cut off from my MFJ-4603 Window antenna feedthru panel. I followed most of Michaels plans with some notable exceptions:

    - instead of a hacksaw blade, which shattered while I was working on it, I used a PCI blanking panel from an old computer. I used a small sledge to flatten out the right angle portion that normally attaches to the back of the computer. The blanking plate already had a hole on the bottom so no power tools were used for this project.

    - instead of using a rubber 'finger piece' to cover the end of the lever, I took two larger flat washers and attached them using the #8-32 1/2" screws.

    For the 3.5mm mini connector, I found an auxilliary headphone jack output on a surplus computer and wired my key to that. I will move this to a box of some sort in the near future so I can put some strain-relief on the wiring.

    I am still fiddling with the clearances a bit, and I need to add a little weight to it (possibly on the bottom) as it tends to move around a bit - but all in all for under $12.00 and one hour, I'm happy with the results.


    Attached Files:

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  2. N1OOQ

    N1OOQ Ham Member QRZ Page

    Not bad... pretty simple.
  3. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    Thanks Thomas - now that I understand the basics I feel comfortable making smaller and more elegant ones - but this will always be my first ;-)
  4. N2UHC

    N2UHC Ham Member QRZ Page

    That's what I did years ago when I built this single lever paddle:


    I did find that the slot blank was very hard to solder to, but I got it to make a good connection.
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  5. KD2NOM

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  6. G3YRO

    G3YRO Ham Member QRZ Page

    Well done guys!

    Remember Meccano? British building sets for kids, containing lots of metal strips and panels with holes in, and nuts & bolts. You could make anything out of it - cranes, engines, even cars:

    I think you can still buy it, and I saw something similar made in China in a shop recently, very cheap.

    Well, a friend of mine made a Key Paddle like these out of Meccano about 50 years ago . . . the standard steel strips are the right kind of springy steel, and they obviously have fixing holes. You just needed to sand off the paint to make contact.

    However . . . a lot of cheap Electronic Keyers just used a piece of springy steel inside like this. I always found it wasn't a very nice feel, compared to a proper lever action that clicks from side to side.

    I used a mechanical "bug" key (so semi-auto) for the past 50 years . . . but decided recently to change to an Electronic Keyer (mainly so I could put CQ calls in the memory). Having bought a cheap ic-based keying circuit, I was lucky that a friend gave me a nice Kent paddle to use with it (put it all in a box, with controls on the top and batteries inside)

    Roger G3YRO
    Last edited: Dec 28, 2017
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  7. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    Thanks Roger! - We still see small kits like this in stores selling 'retro' toys - Erector Set mini kits I think they are called.
  8. N2UHC

    N2UHC Ham Member QRZ Page

    When I was a kid in the 70's, we had similar kits called Erector Sets.
  9. US7IGN

    US7IGN Ham Member QRZ Page

    My key cost me less then 1$ =)


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  10. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    OK - now you're just showing off!

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