CARACTERÍSTICAS
3. Examinar o fase de pos-escritura: debe comprenderse esta fase como un proceso de repaso y relectura consciente de todo
Figure 7-25 The last thing you want to see hissing!
Project 33—Radiation Detector
The true Evil Genius can turn ordinary junk into amazing works of art designed to deliver a good practical joke with precision. Once in a while you may need a sophisticated-looking bit of machinery to help you pull it off. In this case, our ruse is a fully working radiation detector, or at least so it may seem. This prank works great when the
recipient has no idea that you are the ultimate Evil Genius prankster, since it requires a little bit of setup, possibly done by another friend in on the prank. This fake “fallout” detector is nothing more than a variable resistor-controlled audio oscillator that makes cool sounds as a “radiation level” meter moves around just like the real McCoy, of course,
it cannot detect anything, so don’t try to use it anywhere you might suspect of being
radioactive—just run!
To set up this prank to seem convincing, have a friend bring the victim to an area where you are waiting with the device, or show up at the friend’s location wearing some official-looking outfit and knock on the door, claiming that there has been a radioactive material spill into the sewage system or something silly like that. Wave the wand over your friend’s body and let the machine make a little noise by only turning the hidden knob slightly “Whew, you are safe, luckily.” When you get to the victim, crank the knob so the machine screeches like mad while the radiation meter pops over to the danger level, and give your best look of terror as you start asking questions like, “Where have you been?”, “What did you touch?” You could also just show up on the scene and detect fallout on people or objects as well for that spur-of-the-moment gag. Feel free to build the machine any way you like. As long as the control knob is hidden from view and easy to operate, you will have loads of fun finding all that radiation at levels that would make a badly maintained nuclear waste dump look clean!
To build this device, you will need a large analog meter (the bigger the better), a cabinet to place the meter and components into, and a few odds and ends to fabricate a crude radiation detector wand. Figure 7-26 shows the large analog
meter I found at a surplus junk store and the enclosure I plan to use. The most effective placement of the meter will be in full view of the fallout victim, so a strap that allows you to wear the detector box around your neck would be ideal.
Also shown in Figure 7-26 is an old coil-type phone handset cord that will look good as a connection cable between the radiation detector handle and the main unit. There really won’t be much on the inside of the enclosure and hand-held part, but the more “industrial” everything looks, the more convincing the effect will be, so choose a heavy enclosure and good solid switches and cables. The analog meter can be pulled from an old volt meter, stereo amplifier, battery charger, as well as many old electrical test devices. These meters will normally respond to a few volts in order to set the needle flying across the entire range, so just about any type of meter you find can be adapted to work in this circuit. The first thing you will want to do is snap apart the plastic cover to remove the current indicator plate in order to replace it with something much more ominous looking. “DC amperes,” or “Decibels”, is not a label that will scare anyone, so I pulled my meter apart as shown in Figure 7-27 in order to convert it into something much more evil.
The plastic front window will probably just pop right off with a little twist of the screwdriver, and the plate with the indicator numbers may be held on with a small screw. Be careful not to bend the
Project 33—Radiation Detector
Project 33—Radiation Detector
Figure 7-27 Removing the original meter panel
Figure 7-28 Printing out the new meter panel
Figure 7-29 The main unit controls mounted
delicate needle or damage the return spring when you hack into the meter, just carefully take out the current panel as shown in Figure 7-27 if you can. Some smaller meters may be glued together, so you will have to slip your new printed label into place and then tape it secure. As shown in Figure 7-28, “Radioactivity detector” looks much better than “DC amperes” as it was labeled on the original meter. I simply printed the new label from a graphics program, then traced around the paper using the old panel as a guide. The new panel is then taped right over the old one.
The plastic window is replaced on the meter once the new panel is installed, and now you have a brand new meter that looks like the real deal, no
matter what it happens to be measuring. The next step is to secure the meter to the main unit along with the cord that will connect the radiation detection wand and the on–off switch. Mounting the visible parts was easy since my enclosure came with a removable aluminum top that could be cut and drilled. As shown in Figure 7-29, I cut the hole for the meter body, bolted it in place then added an on–off switch, indicator LED and a hole for the wand cord, which will be connected to the hidden potentiometer that controls the unit. You could get fancy and add a few other gadgets into the wand such as a cool light system, or even another oscillator circuit or buzzer for extra show. This design can take on any form your imagination can dream up. I decided to keep things simple and
plain looking, just like a real military-style Geiger counter would look.
Now it’s time to dig through your junk box for a pair of transistors, some resistors, capacitors and wires in order to cobble together the circuit that makes this unit come to life. The schematic is shown in Figure 7-30, and as you can see, it is nothing more than a variable audio oscillator that can be set from a low hum to a high-pitched screech by adjusting the 100K variable resistor V1. This variable resistor is actually mounted in the wand so you can conceal the fact that you are manipulating it when you wave the wand around your victim’s body. Of course, you could also mount it in the main box if you like, as long is it is not too obvious that this is what makes the meter and sound work. The basic audio oscillator is formed by the two NPN transistors, and the variable resistor not only adjusts the frequency of the audio tone, but it also makes the meter swing
from zero to the maximum. Depending on the amount of voltage it takes to max out your meter, you may have to play around with the values of V1 and R5 in order to get a good balance between how high the audio pitch gets as your meter swings to the full end of the scale. Other than that, feel free to mess around with the component values in order to create some cool effects, or even add more than one oscillator for some really confusing sounds as you move the variable resistor.
Once your audio oscillator and meter are getting along together, move the components on to a perforated board and solder them together for mounting inside the main box. As shown in Figure 7-31, my radiation detector is fully
functional and only needs some type of wand to be fabricated in order to conceal the variable resistor at the end of the cable. Remember, bigger and more complex is better when you are trying to baffle your victims with this device, so dig deep into your junk collection for some good parts to make the detector wand from.
I was trying to keep the look of my machine as clean as possible since I planned on giving it a full military-style camouflage paint job, so I just used
Project 33—Radiation Detector
8 ohm speaker Analog meter R1: 10K R2: 1K R3: 10K R4: 100 ohm R5: 10K R6: 100K POT Q1: 2N3904 NPN Q2: 2N3904 NPN C1: 0.01 µF C2: 1 µF +9 V R1 R3 R5 V1 R2 R4 Q1 Gnd Gnd C1 Q2 C2
Figure 7-30 Audio oscillator and meter drive schematic
an old flashlight for the radiation wand, drilling a hole in the side to install the thumb-operated variable resistor. I also turned the flashlight head around so it looked more like the end of some sensor than a flashlight as shown in Figure 7-32. If you want to go all out, a flashing light show inside the wand would really add to the effect, the possibilities are endless. If you are a freak for details, then do an image search for Geiger counter and see how you can make this project look exactly like the real McCoy for those hard to trick
friends that might know a flashlight from a real Geiger counter tube. Yes, you will be a real hit with your circle of friends when your real-looking detector sends everyone running.
Well that sums up the shock and awe chapter. We have barbequed, shocked, zapped, poisoned and then radiated our friends all in the name of good fun (at their expense mostly). But hey, let’s not forget the title of this book, and always remember what comes around usually goes around.