SHOWALL FUN PRANKS HIGH VOLTAGE LAZARUS-64 PHOTOGRAPHY SPY GADGETS VIDEO GAME
Figure 32 - The edge of the beam is the optimal point for clear audio
Figure 32 - The edge of the beam is the optimal point for clear audio

Once you have the beam onto the target area, turn on the light to sound receiver and place it in front of the large laser spot so that the edge of the beam is on the photosensor surface. Usually, the best reception will be received with the edge of the beam on the photosensor, but this will require some experimentation. If the target room is quiet, then there will be no window vibrations so you will have to align the system based on the "pops and clicks" you hear as the beam saturates the photosensor. When the beam is not striking the photosensor properly, there will be a crackling sound similar to an FM radio that has lost its station and when you over saturate the photosensor, there will be a loud "wump" followed by complete silence. The optimal "noise" you want to hear when setting up from a quiet target is a slight hiss.

Unless you are on a ground floor or a concrete slab, the laser will probably jump all over the place as you walk around the room or when nearby vehicles drive past. I found that this laser bouncing did not degrade the received audio all that much, but there are certainly things you can do to reduce this problem. Adding weight near the top of the tripod will reduce any oscillations or at least slow them down. A 5 pound steel weight fastened to the top center of the tripod worked well on certain occasions. Of course, you will just need to experiment and use creative thinking in order to make your installation perform optimally.



Figure 33 - Beaming a window across the street in a controlled test
Figure 33 - Beaming a window across the street in a controlled test

The ultimate test of the Laser Spy system will involve listening to a conversation in a room that is remotely located from the device. Of course, you would "never" try to eavesdrop on an unsuspecting party, so you will need to have a helper at the remote location to help you test your system. I originally built this unit to dispel the many myths about its "ease of use", but was seriously surprised at how well it does work of you can actually get the return beam aligned properly. In my test, I set up the unit and then went to the target location and spoke loudly right at the window, expecting that the received audio would be barley understandable. Well, if you've seen the video then you can see that the reception was very loud and clear, to the point that it almost sounded like a radio transmission! I honestly did not expect it to work that well.

Of course, make no mistake - alignment from across the street is no easy task and every single factor has to be completely in your favor to have any chance at all of success. The target window must be at a very precise angle to allow the beam to come back to your location, and the conversations must be loud enough to create a decent vibration on the window. Gas filled high efficiency windows further reduce your chances, and any noise in the room may completely overpower the conversations. Remember, I was in the totally silent room almost yelling directly at the window. Further testing proved that lower level conversations were also possible, but computer filtering would be necessary. In my tests I also found that the infrared laser did better than the visible red laser but it was a magnitude more difficult to get proper alignment. So, my conclusions are that the Laser Spy device is definitely a powerful tool, but your chances of pulling up in a darkened vehicle to "point and shoot" are almost zero. Setup and alignment requires extremely careful and tedious planning, often resulting in failure. It's not the hardware that fails; it's the path of the laser beam.

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