Hackaday links: July 25, 2010

Radio Receiver

If you never got the chance to build one as a kid [JoOngle] takes you through the steps to build your own radio receiver. Details are a bit scarce but it’s nothing your friend Google can’t help you out with.

Fixing a Blackberry trackball

If your Blackberry trackball stops working well you can try this non-technical fix. Remember when mice used to have a ball in them and you would need to clean out the gunk from time to time? Forcefully skidding your Blackberry across a piece of paper does a similar service.

Linux time lapse

Open source can be a great help to small businesses. Here’s a way to use a Linux machine to make time-lapse movies from surveillance camera feeds. We especially enjoy the use of a desktop wallpaper that has the terminal commands necessary to start recording.

Host a webpage with Dropbox

Here’s a way to host a simple webpage using Dropbox. It’s one of those easy ideas that you wouldn’t come up with yourself. When you place an HTML file in your Dropbox you can get a public URL which will be built as a webpage when visited with a browser.

Inline splicing

To round out the weekend here’s [Osgeld's] tips on inline wire splicing. We laughed as he recounted spearing himself with stray strands. This is pretty simple stuff but he’s explained it well and who’s to pass up a good tip?

Comments

  1. Joe says:

    Sorry, but the splice instructions are wrong.

    For stranded wire, as shown in the tutorial, you should open the strands and mesh them into each other before twisting together. This is much stronger and not prone to uncurling, as a simple twist is.

    For solid wire, look up the “Western Union” splice, which uses two different twists for strength and stability.

  2. Spork says:

    The radio video was pretty good, but as noted it’s better to read more about it if you’re truly interested.

    On wire splicing, the ‘pigtail’ method is preferred for gang boxes where you use a twist connector and it doesn’t need to look pretty, but does need to come apart quickly/easily.

    The method shown is definitely the preferred method for small electronics or anything that is to be a ‘finished product’.

  3. Spork says:

    @Joe, I have to disagree with the meshing of individual strands. The method described is plenty strong and does not slip apart when done correctly.

  4. kiernan says:

    Please, no more instructables. Are there not any open sites to direct traffic to?

  5. xorpunk says:

    dropbox pages literally take like 30 minutes to knock offline, and that’s just a single attack machine not ddos. Of course this is the case with all ‘free’ webhosting.

    Just thought I’d mention it. People get these cheap or free hosts and act like it’s a sophisticated attack when it ends up tanked.

  6. Jake says:

    I agree with Spork, this method is more than adequate for this kind of wire splicing, especially when combined with a nice adhesive-lined heat shrink.

  7. nubie says:

    Forget “spearing yourself on stray strands”.

    I was wiring Co-ax one day and a small coil with a stripped end slipped out of the attic and the core actually got stuck (embedded) in my scalp.

    It must have been bent like a hook at the end, cause I couldn’t pull it out at first.

    Moral? Watch out wiring heavy sharp wire overhead.

  8. mostlymac says:

    I never seem to have a soldering iron on hand, so I abuse the in-line splice. With single strand, I use the Western Union (which just came to me naturally, it’s the most logical means in my mind), but with stranded wire, I prefer to mesh the two together, then twist (and shout).

    As for the other links, I had an awesome radio kit that I built as a kid. Global Electronics I think. It had everything to kick start an engineer’s imagination, and I wish that I would have bought the fire/police scanner kit as well.

  9. Alex says:

    If I recall correctly Blackberry trackballs (at least Pearl and Curve) are removable and cleanable. I consists of the trackball in a squarish assembly with rollers and magnets. All of the assembly is quite submersible in rubbing alcohol. All that is needed is to pop off the ring with the appropriate prying tool of your choice and the assembly will lift out. I could be wrong on some models, but I can personally confirm this on the Pearl and Curve series. Other series may have this too.

  10. DETN8R says:

    The simple hook and solder method for wire is an IPC standard.

    Tin and hook the wires to each other then add more solder.

  11. jh says:

    @DETN8R

    I add a twist (hook the wires together and then twist the overlap back on wire). I also don’t solder before hooking, just twist the strands together. Then solder the joint solid and wrap with tape/shrink wrap. Have yet to have any of those joints give up… and some are going on 15 years old.

    Usually the wire gives out from movement/vibration before the joint will, even with the simple twist shown here.

  12. SleighBoy says:

    Capturing video from a cam via one shell script is all fine and dandy, but since it is already on a *nix system, Motion ( http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome ) will do a lot more.

  13. Stephen says:

    Sounds like they’re laughing at your pain there, Osgeld :P.

  14. cgmark says:

    The radio in the link is basically parts from a regular radio on a circuit board. The real hack is making a foxhole radio. Only parts you need are wire, razor blade, safety pin, pencil, and earphone . No battery or other power required.
    You can learn a ton about how a radio works by building one. When the zombie apocalypse happens and there is no power, you will be able to hear how close they are getting!

    For wire connections I twist the strands together with pliers to make an almost single conductor then us the western union method to join the wires. The wire will break usually before the connection will. No solder needed. Called western union because it is what was used over 100 years ago on telegraph wires so you know it is a strong connection. I was taught this method as a kid by a guy that was a ham.

    It also the method required in the military when joining wires.

  15. mowcius says:

    Oh Osgeld, you really must be bored sometimes :p

  16. woutervddn says:

    @kiernan: Instructables is free. I have an account there and I tell you it’s damn handy for some tutorials.+ I’ve never got unnecessary mails on instructables.

  17. pod says:

    the blackberry tip is exactly the same as the one you posted long time ago about fixing the “broken” one button apple mouse scrolling ball

  18. walt says:

    Please, no more instructables!

  19. The Steven says:

    It’s good to know that I’m not the only one that knows this as a “Western Union Splice”

    http://www.tpub.com/neets/book4/12a.htm

  20. just a quick example of dropbox website hosting.

    http://dl.dropbox.com/u/4092999/main.html

    it will soon add some of my tinkerings to it, but i think it looks pretty enough for half an hour worth of work

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