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 (http://www.k4icy.com/weekend_radio_depot_cootie.html).

    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.

    Pictures:

    https://drive.google.com/open?id=1sD2Ug3bknyIvgJotaM7GkkZ-Yuj6kgpu

    https://drive.google.com/open?id=1iOBPjB6NHGZVu7UDRZcrZpt1l8Nf_oR-

    https://drive.google.com/open?id=1YYJ0AcTTmZmFLaK_rlvpwsNo82GsTrMg

    https://drive.google.com/open?id=1E-rm5ZlC5b9OPiLAXE78PwZHVZDH1y06

    https://drive.google.com/open?id=16K84QBneFLsyy4iXrFegmvAdIisjjKZx

    https://drive.google.com/open?id=1t3gNQpoDQb_fQoYb_4NgBVa5oi9hNdKC
     

    Attached Files:

    AI3V, N1OOQ and VK4HAT like this.
  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:

    [​IMG]

    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

    KD2NOM XML Subscriber QRZ Page

    Excellent!
     
  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:
    [​IMG]

    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$ =)

    [​IMG]

     
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  10. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    OK - now you're just showing off!
     

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