SHOWALL FUN PRANKS HIGH VOLTAGE LAZARUS-64 PHOTOGRAPHY SPY GADGETS VIDEO GAME
Figure 2 - A small speaker will be used to simulate a vibrating window
Figure 2 - A small speaker will be used to simulate a vibrating window

The first time I experimented with a laser spying device was in the 1980s when I found a DIY article in an electronics magazine. Lasers were huge, expensive beasts back then, but I was nerdy enough to have one to mess around with and followed the instructions in the article. In the end, the system was found to be 100% useless, and rumor at the time suggested it was all just a hoax. What happened was that the article failed to mention that as cool as this device was, it was extremely difficult to set up in the real world, especially when trying to bounce from a distant window. Believe me when I say that this device does indeed work, but using it to spy across the street will require a serious amount of setup, fine tuning and patience. To be perfectly honest, your chances of simply beaming toward your neighbor's window and hearing anything are about 1,000 to 1 against you. So many factors have to be in your favor, such as the type of window, the alignment of the structure, the time of day, the level of sound, and mostly, your patience level. I have done a successful window bounce from across a city street, but it was NOT an easy task, so keep that in mind. Any site selling this device in kit or plans form claiming that it is "point and shoot" should be deleted from your favorites in a hurry!

To create a "test window" to allow the deflection of the laser beam, a small speaker is connected to some audio source such as a radio or computer headphone port. Don't worry about how loud the audio source will be; as long as you can just barely hear the sound on the speaker, it will be good enough. Any small radio or portable music system will have a headphone jack that you can connect to your speaker. The size of the speaker is also not important as long as it is large enough so that you can glue a small bit of mirror to the center cone to allow a surface to deflect the laser beam. Some speakers already have a chrome dome in the center, so if you can find one like that, then you will not need to use the mirror. Solder the appropriate jack to the speaker terminals; this will likely be a 1/8 inch headphone jack.



Figure 3 - Add a reflective surface to the center of the speaker
Figure 3 - Add a reflective surface to the center of the speaker

Any small piece of a highly reflective surface such as a mirror can be used to deflect the laser beam during these tests. A mirror works best, and a piece can be snapped from an old mirror using pliers or a small dental mirror can be taken apart for to remove the small round mirror from the plastic housing. A hot glue gun or even some double sided tape can be used to glue the small mirror section to the center of the speaker. The size of the mirror is not important since the laser beam will only be a few millimeters across when it strikes the surface. If you intend to snap a bit off a larger mirror, use a cloth or paper towel to wrap the corner so that small slivers of glass do not fly from the mirror as you break it. A highly reflective plastic or metal surface will also work for this experiment, and even a shiny dime will do the job in a pinch.

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