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Tuesday, March 31, 2015

Almost Enough to Make You Abandon Manhattan: John's SW-40

Hi Bill,
You said you didn't mind if I sent you some of my finished projects so here is the latest.  I scratch built the SW 40 that I had previously built from a kit by K1SWL.  I always liked that radio, and thought by laying it out I would learn more about it.  In testing it out after I aligned everything I made a qso with Mike (K3WAS),and got a good report, and I didn't let out any of the magic smoke or sacrifice any chickens.  You gotta love this hobby. 
The rig tunes from 7.034 to 7.063, and I had about 2.3 watts out, but ran into some slight problems with instability at the end of the qso with Mike. The PA was getting a little hot, but with the excitement of having it work right out of the gate it really didn't matter at the time.  The board layout was done with express PCB, and using the toner method, placed it on the board.  Chuck (K7QO), has some great youtube videos showing the process. I have to admit I got more knowledge by laying out the board as opposed to manhatten construction, and came away with a better understanding of the radio itself. 
Now to build the case.  the board is 5.25 by 7.25 inches, and I may have to sneak one of my wife's alum cookie sheets to fabricate the case.  She doesn't bake till Christmas so it will be a calm summer.  I also made provisions on the board for a digital readout, but for now I just want to enjoy the rig as it is.

Thanks to both you and Pete for taking an interest, as well as the great job on soldersmoke.
N8RVE  John

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  1. An article on 'the laying out of boards' would be appreciated.

  2. John, Awesome job! We are always looking for new innovative ideas and neat looking projects. Please share more.


  3. As far as laying out the boards, K7QO, has about a dozen youtube videos that give you a quick lesson on Express PCB, up to etching and making your own etching fluid. I highly recommend them for those wanting to get started.

  4. I would also echo the comment about Chuck's videos. They meticulously show what he calls the "muppet method".
    Aside from producing something close to art (in the case of John N8RVE), you don't need to drill all those holes as with traditional boards. You can use the method for simple quick boards too as with this example of a tone injector (circuit from George Dobbs G3RJV).

  5. Don't hide that board, that's a work of art. Encase it in plexiglass or something and show it off. You did good, be proud of your work.

  6. Thanks for the comments on layout, I'll follow the links up. I was particularly thinking about rules of thumb for good RF layout practice.

  7. Thanks everyone for the compliments here and also via email. It was a fun build, and I am looking forward to the next project, I just don't know what it will be yet.

  8. Fantastic work John. It just goes to show that if the kit you really wanted to build is no longer available, that should not be a deterrent.You have created something more unique than an SW-40 kit John - a one of a kind!


  9. I just saw Chuck's videos on making boards. Makes me want to get the supplies to start doing that too. Might be a good way to bring back some old designs. Might be harder since a lot of designs use programmed chips, that I have NO experience with. Still, looks like it could make for some fun times melting some solder.



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