RF-Radiation Detector Circuits
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In this page we will show how you can simply construct such a meter, which is good to have one, to show not only the existence of radioactive materials but also the dangers arising from them. The Geiger–Müller counter can be compared to a photometer. The....
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In the absence of radiation, no current is drawn. At normal background radiation levels the power consumption is extremely low. The instrument may be left on for several months without changing batteries. In this way the detector is always ready to indicate....
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A single 6.75 V mercury battery powers the counter, which features a 1 mA count-rate meter as well as an aural output. A regulated 900 V supply provides stable operation of the counter tube. A multivibrator, built around a differential power amplifier IC2,....
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The circuit can be tuned to respond to signals between 50 MHz and 500 GHz. The economy model is shown in Fig. 1, and the deluxe model is shown in Fig. 2.The first op amp in each circuit functions as a current-to-voltage converter. In the economy model IClb....
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A commercial diode is the detector in this highly accurate radiation monitor. The lowdrift FET-input op amp amplifies detector current to a usable level, and the chopper-stabilized amplifier then provides additional gain while minimizing any error caused by....
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A sensitive radiation monitor may be simply constructed with a large-area photodiode and a quad operational amplifier. Replacing the glass window of the diode with Mylar foil will shield it from light and infrared energy, enabling it to respond to such....
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The Geiger tube needs a high voltage supply which consists of Ql and its associated components. The transformer is connected in reverse; the secondary is connected as a Hartley oscillator, and Rl provides base bias. Dl, D2, C4, and C5 comprise a voltage....
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A simple inventer and NAND gate can be connected to yield a highly compact and reliable digital frequency detector. This circuit can detect frequencies up to 3 MHz with 50% duty cycles. When a frequency, j,, appears at the input, points A and B detect a....
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The high-speed peak detector uses a highly accurate, fast s/h amplifier controlled by a highspeed comparator. The s/h amplifier holds the peak voltage, until the comparator switches the amp to its sample mode, to capture a new, higher voltage level. The....
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This rf probe is coupled with a fiber-optiCJ:able to the test equipment. It utilizes inexpensive components to improve probe performance at UHF frequencies. The receiving antenna in this probe feeds an envelope-detector diode. After amplification by the....
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Transistor Q1-configured as a source-follower buffer stage, offering a bit under unity voltage gaingives tbe unit a high-impedance input of about 1 MO shunted by about 10 pF, which keeps only minimal loading on tbe equipment being tested. C1 serves as....
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This logic probe has four channels and uses two IF quad comparators to drive four bicolor LEDs. SI and SIB program the co..
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A simple detector of radar signals uses the junctions of the input transistors of an LM1458 op amp as RF detectors. The lead..
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The circuit, built around a single integrated circuit (Ul, an MC3403P quad op amp), three transistors (Q1-Q3), and a few support components,.receives its input from the antenna (ANT1). The signal is fed through a high-pass filter, formed by CI, C2, and Rl,....
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The circuit is built around a 4049 hex inverter (Ul), a pair of 555 osciliator/timers (U2 arid U3), two transistors, a Geiger-Muller tube, and a few additional support components. The first 555 (U2) is configured for astable operation. The output of U2 (a....
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Ql is a pnp power transistor used in conjunction with a ferrite transformer to form a blocking-type oscillator. This oscillator is a fixed- frequency type, and the feedback to sustain oscillations is from capacitor CI. Because of the turns ratio of Tl, the....
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Useful as a transmitter tune-up meter or an RF sniffer, this is an RF field strength indicator that is loosely based on the Broad Band RF Field Strength Probe, described elsewhere. It detects RF via a square law detector, basically its a crystal set with....
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The circuit of Figure 1 includes a PIN photodiode that detects individual photons of gamma radiation. The reverse bias on the photodiode sometimes creates a depletion region. When such a photon strikes this depletion region, a small amount of charge....
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Modern high-performance transmitters require accurate monitoring of RF power, because most cellular standards depend on strict power- transmission levels to maintain an effective network. Regulation of transmitted-signal strength also lets you build lower....
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Sending Morse on a rig without a sidetone is not impossible, but is not particularly pleasant either. This battery-powered monitor has been designed to provide an audible indication of keying for those whose rigs lack a CW sidetone. Its sensor wire is....
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RF is just way too cool not to use in your designs. But if you`re a newbie like me it is difficult to successfully build solid RF transmitters and receivers. When I started out I didn`t realize that the larger breadboard I was working off of was causing a....
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This circuit is so sensitive it will detect "mains hum." Simply move it across any wall and it will detect where the mains cable is located. It has a gain of about 200 x 200 x 200 = 6,000,000 and will also detect static electricity and the presence of your....
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No description available...
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This simple circuit is sure to have the police beating a path to your door - however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat. The circuit transmits on Medium Wave (this is the small....
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This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED.
The device must be placed a few centimeters from the cellular phone, so its sensor coil L1....
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This simple circuit produces a loud trilling noise, if no valid transmitter signal is received. This frequency must correspond with the resonant frequency of the piezo element, otherwise the sound level will be very low...
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This project involves making several modification to an early 1960s era Victoreen CDV700 or CDV600-6B geiger counter. These counters are available on E-Bay for around $50 to $100. The modifications use modern electronic parts to improve the counter`s....
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Old TV tubes are used as cold cathode x-ray emitters in a simple apparatus developed by Bob Templeman of Chicago, Illinois. With selected beam power tubes of the type used in the high voltage section of TV receivers, the intensity is adequate to make x-rays....
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This circuit is not open for discussion. Although working perfectly, it was experimental. I will answer no emails in regards to this circuit.
If you are looking for a more serious and reliable bug detector, go to the Countersurveillance Monitor article on....
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Ions are defined as electrically charged atoms. Positively charged ions have a deficiency of electrons, and negatively charged ions have a surplus of electrons. An ion can also be classified as an atom or molecule with an electrostatic charge. Another....
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This Mini FM Bug Detector is basically a broad-band receiver. It picks up the complete band from below 80Mhz to 150MHz and almost anything that transmits in that band will be detected. If a bug with a sensitive microphone is transmitting nearby, the result....
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Here is a simple tool to check the degree of radiation from an electric or electronic instrument. The LEDs in the circuit will give a running light pattern at the moment the circuit senses electromagnetic radiation from the device. It can detect radiation....