Knock Detection Listening Device

Written by: Dzaster

     This definitely was not my idea. I just came across THIS article on AutoSpeed a couple months ago, and so I figured I might try it. Its a device that is used to supposedly help one hear if an engine is detonating.

     Went and had a look at what kind of devices were floating around eBay and what'd ya know?!!! A toy! I got mine for $2 shipped.

     Right away, crack it open.

     Get the microphone free(looks like a little battery attached to the red/black wires.

     Cut the mic off, route the wires out the housing of the device and close it up.

     I don't have a picture of what I used but I just found a 4ft long USB cable and cut off both ends, pulled back the insulation and shielding and revealed the wires. All needed was 2 wires. Soldered 2 wires from one end of the cut USB cable to the 2 wires coming off the mic and insulated it.

     The other end of the USB I soldered to the 2 wires coming out the device that use to be connected to the mic. Just match colors(couple pictures up).

     Then you'll have to get one of these clamps. I had one just laying around. I know I've seen them at RadioShack so if you need one they should have it. Anyways, you'll mount the mic to it like this. So this first pic I just slipped the mic/wire in and crimped down the wire with the material at the end of the clamp.

     Another thing you can do while your at this is get rid of the markings on the lenses. Take a razor and shave the markings off as close to the lens as you can, then clean it up with some 400 grit paper. You just want to sand enough to make them disappear.

     Keep working the area with the buffer until there's no sign of the marks.

     If you have deep scratches just keep working on the area till there gone. Like anything, you can do a little or a lot. The more you work on a lens the better its going to look. Practice a bit, keep compound on the wheel, keep it moving so you don't melt the lens, and shine those suckers up to what ever level your happy with. This was a so-so polish on this lens and it took about an hour.