All photos courtesy of the author. Where Is It? By Paul Alves, Carmen Wong, Matthew Clampitt, Eric Davis and Eunju Kwak INNOVATION INSIGHTS with Richard Langley WE LIVE IN A POLLUTED WORLD. Sometimes even pristine environments are desecrated. No, I’m not talking here about the rubbish on Mount Everest, nor the leaching of heavy metals from tailing ponds, nor the plastic trash in the oceans, nor the sulfur dioxide in the atmosphere. I’m talking about radio-frequency pollution. Just as we would like to have our physical environment free of pollution for our better health and that of the ecosystem, we would like the radio spectrum to be free of pollution so that its users — virtually everyone on the planet — can have a better RF experience, whether it be when listening to the radio, using a cell phone or operating a GNSS receiver. We usually call RF pollution interference, or RFI for short, as it interferes with the signal we are trying to receive. RFI can be accidental or deliberate, in which case we call it jamming. As a shortwave radio enthusiast, I am familiar with both types of RFI. Although the majority of the world’s radio stations attempt to coordinate their broadcasts to ensure that two stations don’t try to beam their signals to a particular area on the same or an adjacent frequency at the same time, it does happen, ruining reception. And if a country doesn’t want its citizens listening to certain foreign radio broadcasts, it might attempt to jam them as the Soviet Union did in the past and as China, North Korea, Cuba and several other countries still do. In this month’s column, we look at GNSS interference. In many cases, GNSS interference is accidental, with a nearby radio device putting out a signal at a fundamental frequency or a harmonic, which lies within the passband of one of the GNSS frequencies. It could be intentional, too, and we’ve all heard about GPS jammers including the so-called personal privacy devices that deliberately interfere with GPS signal reception. Is there any way to detect GNSS interference and to find its source so that remedial action can be taken? Yes and yes. A team of authors from NovAtel tell us how. Interference is a growing concern among GNSS users, particularly in parts of the world where radio frequency transmission is not strictly regulated. Intentional interference and jamming is cheap and relatively easy to obtain in the form of personal privacy devices (PPDs). These devices can sometimes cause unintended interference and jamming to important infrastructure such as an airport. In this article, we describe a method for creating an interference map using the NovAtel OEM7 Interference Tool Kit (ITK). The ITK is capable of detecting and eliminating interference, and can be used to measure the power of a received interferer. When data is collected for an area around a static and continuously operating interference source, it can be used to map out the interference over the affected area. We overview a method for mapping the interference and, using a model of power loss over distance, creating a map of the interferer’s likely position. We also discuss simulated results and three case studies with live (real-data) interference sources from India, Canada and Japan. NovAtel introduced the ITK in 2016. The ITK’s interference detection provides a list of sources, which includes an estimate of the frequency, bandwidth and power of the measured interference. It also provides the power levels across the entire frequency band of the front end. Either of these can be used as measurements of the received interference power levels. When the power levels for a given frequency are combined from multiple locations, they can be used to estimate the power and location of the interference source. The received power levels can also be combined to estimate the interference power as a function of location. The performance degradation experienced by one receiver at a given interference level can be extrapolated to other receivers at the estimated interference levels. INTERFERENCE DETECTION The ITK tools include the ability to visualize the power received across the input frequencies (front-end) bands. This can be used to quickly and easily identify any irregularities in the spectrum. These irregularities could be caused by internal interference, which is interference between electrical components introduced through hardware integration or installation. It can also be caused by external interference, such as by a PPD or other nearby radio transmitter. The ITK’s detection feature identifies potential interference and provides a list of the interference power, frequency and bandwidth. This makes it easier for integrators to automate responses to potential interference without the need to scan the spectrum themselves. FIGURE 1 shows the received signal power and interference detection threshold for the GPS L1 frequency band. In this case there is no interference detected. FIGURE 1. Received signal power (blue) and interference detection threshold (red) for L1. The detection threshold is adjustable. However, if it is set too high, it can cause interference to be undetected; if it is set too low, it can cause false detection. For this example, a fairly low value was chosen because we were willing to manually identify the interference source and ignore any false detection. The ITK also includes tools to mitigate interference, limiting or eliminating its impact. This includes a high dynamic range mode, which is effective in reducing the impact of interference. If this is not sufficient, then notch or low-pass filters also can be applied to completely cut out parts of the spectrum to neutralize the impact of interference or jamming. FREE-SPACE LOSS The mapping algorithm, which will be discussed later, requires a model of the power loss as a function of distance (d) to the transmitter. As the wave spreads from the transmission source, the power is lost according to: (1) where Lp (dB) is the power loss in dB, d is the distance in meters, and λ is the wavelength in meters. This equation can be expanded into a function of frequency (f, in Hz) and distance (d, in millimeters). Changing the units in this equation changes the constants. (2) For example, if the transmitter is broadcasting at 1.237 GHz, then Equation (2) gives (3) This ideal power loss is significantly increased by physical obstructions that are common, such as vehicles, buildings, trees or the terrain type. Different materials can have significantly different impacts on the power loss. Some researchers have used a precomputed power map and map matching for indoor positioning. This method uses the expected received power to position a receiver. The same algorithm that is used to position the receiver could also be used to position the transmitter. FIGURE 2 shows the received power as a function of distance that was observed for the Calgary test. There is a large variability in the power, likely due to natural obstructions. FIGURE 2. Received power as a function of distance from the transmitter. The equation for the line of best fit of this data is significantly different from Equation (3). This is likely due to the obstructions and limited number of data points. Due to problems with inaccuracies with this data fit, any further power calculations will use Equation (2). MAPPING THE INTERFERENCE IMPACT Using a single observation of the received interference power, a profile of the transmit power as a function of location can be created using a power decay curve similar to that shown in Figure 2. If we assume that the transmitter is at a given position and use the decay curve through the observed power, then we can estimate the transmit power at that location. When we do this for multiple locations, a power profile is created. This process is shown in FIGURE 3. When these plotted estimates are connected continuously, then we get a power profile. FIGURE 3. Received power as a function of distance from the transmitter. This power profile could pertain to a lower power transmitter that is relatively close to the receiving antenna or could be a stronger transmitter that is farther away. A single transmitter at any location could be responsible for the received power depending on the power of the transmitter. When additional measurement points are added at different locations, the estimated powers of the transmitter for each individual observation can be combined. The estimated transmit power at some of the potential transmitter locations will match between the observations. For potential interferer locations that are far from the true transmitter location, the observations will conflict with each other. Creating this type of power profile can be useful for pre-analysis. If we assume that none of the measurement locations can observe the interference, then the received interference must be equal to or less than the noise floor. If we assume that the received interference is at the noise floor, then we can use this profile map to identify the power of any hidden, undetectable transmitters in a region. An interferer may be broadcasting under the noise floor, undetectable at that power and distance. For example, if we want to monitor an area for interference around critical infrastructure, such as an airport, then we can deploy a network of ITK receivers. If no interference is detected, it is still possible for interference to be present if the power level of the transmitter is low enough that it does not reach any of the receivers above the noise floor. This analysis can be used to estimate the minimum detectable interference across the area, and used to determine the receiver network spacing and locations to ensure the minimum detectable interference is immediately detected. FIGURE 4 shows an example of measurement points from the India case study. It shows the estimated power of a potentially undetectable interference source if no interference is detected anywhere at the measurement points. Lighter colors indicate a higher undetectable interference power. Notice how it is possible to miss a weak interferer that is close or a high-powered interference source that is farther away. This also illustrates how much information we can gather from zero-observation points where interference could not be detected. FIGURE 4. Locations and power of possibly hidden interference sources that would be undetectable by observation points, shown as blue dots (Map data: Google, DigitalGlobe). This method could be used to determine the path or spacing of receivers to monitor a region to detect interference at a certain level. With some history added into the model so that the uncertainty increased over time, a single receiver or a fleet of receivers could plan out their routes to monitor for interference. The estimated interference source power can be used to determine the impact of the interference and give an estimate of the location of the interferer. A single static interferer will be assumed when estimating the location of the interferer using a goodness-of-fit model. A grid is created over the interference area. For each point in the grid, the attenuation (power loss) model is used to calculate the residual between the minimum transmit power and all power measurement points. If the residuals are low for all the observed power locations, then this is the most likely location of the interference transmitter. FIGURE 5. Example of the goodness of fit for potential transmitter location and power. FIGURE 5 shows an example of this goodness-of-fit test. The red dot shows the location of a potential transmitter location under test. Using the distance attenuation model, the predicted received power for each of the measurement points is calculated. The difference between the expected received power and the actual received power is an indication that this is not the correct transmitter location. The root-mean-square error of the fit error for all the observed points gives a likelihood that the transmitter is at this location. SIMULATED RESULTS Using the goodness-of-fit method, we can generate reasonable visualizations of the interference effect. FIGURE 6 shows an example map produced from simulated interference to the east. FIGURE 6. Interference map from a simulation where the interference is on the east side (Map data: Google). The expected power attenuation model matches perfectly with the data because it is a simulation. Similar results were obtained when the interference was assumed to come from the west and north. The yellow line shows a “roller-coaster” plot of the interference power. The height of the line shows the relative received power. Notice that it increases as we approach the source of the interference and decreases as the path moves away from the interference. A combination of the roller-coaster plot and the map give a quick visualization of the impact and location of the interference. There is a slight ambiguity between the east and west side of the road because the transmitter is close to the road. The goodness of fit works very well in this case to identify the location of the interference source. FIGURE 7 shows a case where two interference sources are simulated. In this case, the model breaks down because it assumes that there is only a single interference source. The model clearly has difficulties determining the location of the interference. Even with accuracy issues, the model could still be used as a visualization of the interference that is easier to interpret than looking at numbers in a table. FIGURE 7. Interference map from a simulation with 2 interference sources (Map data: Google). INDIA DATASET This dataset was the initial motivation for this work. A customer reported intermittent tracking problems with a newly installed receiver. The receiver would stop tracking for a few hours every evening. Customer service visited the site to investigate. Because of the intermittent nature of the problem, interference was suspected. An OEM729 receiver was walked around the affected antenna in an attempt to find the source of the interference and also to prove to the customer that interference was in fact the cause of the tracking problems. FIGURE 8 shows the collected measurements. The numbers shown are the received interference powers at each location. It is possible to approximate the location of the interference and the impacted area by looking closely at the measurements, but it takes some close examination and interpretation. FIGURE 8. Received interference power measured when searching for interference in India. The source of the interference was identified using this approach. It was found to be a weather station, which performs a nightly upload of data collected throughout the day. This weather station broadcasts at 1580 MHz, which was jamming L1. The customer was able to move the interfering antenna to another site. The customer also could have used the ITK to apply a notch filter, which would have mitigated the interference’s impact, but it is better to remove the source of interference if possible. Using the data points collected, an interference map can be generated using the method described. This map is shown in FIGURE 9. The lighter color indicates a higher likelihood that the interference transmitter is at that location. The location of the transmitter is also shown in the figure. The likelihood map is very close to the actual location of the transmitter. It gives a quick and easy-to-interpret visualization as opposed to individual measurement points. FIGURE 9. Interference map for the India case study (Map data: Google, DigitalGlobe). CALGARY DATASET We were made aware of a potential unintentional L2 interference device and took it to Cross Iron Mills mall, north of Calgary, Canada, to investigate. FIGURE 10 shows a map of the area. FIGURE 10. Map of the test area showing the location of the interference source. We drove the path shown in blue to characterize the interference, and collected data using an OEM729 receiver with the ITK feature. Two buildings are near the interference source: a smaller building to the north and a large building to the south. These buildings block and shield the receiver from the interference when it is between the interference and the receiver. The interference device was a transmitter to send video from a drone to a monitor, broadcasting at 1.2 GHz with 800 milliwatts. It was purchased online with no warnings about potential impacts it may have on other systems or devices. As recreational drones (and their electronics) become more popular, unintentional jammers and interference sources could become commonplace. We have no continuous monitoring and enforcement for short-range and short-duration unintentional jammers such as this one. Although many commercial-grade receivers, such as ones common in cell phone and GPS watches, were unaffected because they only operate at L1, the box the device came in also indicates that there is a 1.5-GHz model capable of broadcasting at 2 watts. With 2 watts at 1.5 GHz, GPS L1 would be significantly jammed. This emphasizes the need for interference detection and mitigation. Nothing is stopping recreational hobbyists from accidentally jamming a significant number of users and services. FIGURE 11 shows the roller-coaster plot of the interference observed during the test. The height of the yellow bars indicates the received power for the L2 interference. The power is generally higher closer to the interference source and decreases as a function of distance; however, there is a lot of deviation. Physical obstructions also cause significant decreases in received power. FIGURE 11. Observed power of the interference source (yellow) over the test course (Map data: Google, Landsat / Copernicus, DigitalGlobe). For example, on the north end of the small building, shown on the right side of the figure, the observed interference power drops to almost zero despite being relatively close to the interference source. The large variations in power throughout the southern loop may be due to partial obstructions from parked cars or outcrops of the building. These physical obstructions cause larger decreases in received power than simply moving the antennas away from each other. Since the interference was only broadcasting on L2, a position is still available through the other GNSS frequencies. The GPS receiver had difficulty tracking GPS L2 signals because of the interference. FIGURE 12 shows the number of GPS L2 signals tracked. As the receiver approached the interference source, it became more and more difficult to track the L2 signals. As the receiver moved away from the interference, or behind a physical obstruction (like a building), the impact of the interference decreased and the signals were reacquired. FIGURE 12. Number of L2 satellites tracked (red) over part of the test course (Map data: Google, Landsat / Copernicus, DigitalGlobe). This shows how a simple device can inadvertently be harmful. Anyone could have purchased this device to transmit video from their recreational drone. Since this device only broadcasts on L2, the GPS of the drone and many nearby devices would have been unaffected, while almost completely jamming and disrupting any dual-frequency receivers nearby. FIGURE 13 shows the interference goodness-of-fit map from the real data test. The map shows the correct trend, but the peak of the map does not include the actual location of the interference transmitter. This is due to inaccuracies in the power attenuation model. For example, a significant shift to the south is due to the rapid decrease in power when moving behind the north building. FIGURE 13. Interference map from the real-data test. When only the southern dataset is considered, we get a more accurate map, one not impacted by the northern building. This is because the attenuation model does not account for obstructions. The performance of this kind of model could be significantly improved with a model that includes the topography and buildings. Despite the inaccuracy of the map to precisely locate the interference source, these simple model maps give a nice visualization of the interference. TOKYO REAL DATA RESULTS We received a report of interference in Tokyo, Japan, and took a receiver there to investigate. FIGURE 14 shows the maximum received power throughout the dataset. The interference around 1570.69 MHz is obvious and easily to identify in the figure. FIGURE 14. Spectrum power level for the Tokyo dataset. FIGURE 15 shows the observed power of the interference source when walking around the building. There is a peak in the received power when moving to one side of the building, while the observed power is relatively constant over the other three sides of the building. This strongly suggests that the interference source is along the one side of the building. FIGURE 15. Observed power of the interference source (yellow) for the Tokyo dataset (Map data: Google, Zenrin). This figure also shows the estimated goodness-of-fit interference map produced using the algorithm described earlier. The source of the interference could not be conclusively determined; however, we believe that the source was emanating from one of the vehicles in the parking lot. This real example illustrates how useful this visualization of the observed power is in understanding the nature of the interference, identifying the source and localizing its effect. The interference in this case did not cause a noticeable change in the number of satellites or signals tracked. CONCLUSIONS This article showed a creative and useful application of NovAtel’s Interference Tool Kit available as a feature on the OEM7 line of receivers. The ITK can be used to create maps that show the estimated location of an interferer as well as the impact of the interference on other users. We demonstrated this using simulated datasets where the agreement between the simulated and actual loss-of-power models made for overly optimistic results. Three case studies are also shown: The original motivation for this work was a customer-service case in India. The second is a case in Calgary where unintentional interference was being caused by a drone video transmitter. The third dataset from Tokyo was a similar example, where, unfortunately, the true interference source could not be conclusively identified. The three interference case studies show the importance of interference detection and mitigation because intentional and unintentional interference sources are easy to obtain and are not easily monitored or restricted. In one of these cases, a device that was naively purchased online as a UAV video transmitter ended up jamming GPS L2 in an area of roughly 2,000 square meters. With interference mitigation, it is possible to continue to work and operate in these environments without interruption or significant impact. ACKNOWLEDGMENTS The authors thank Bryan Leedham and Saravanan Karuppasamy for sharing their customer stories with us and providing us with the data for the case studies. This article is based on the paper “Interference Likelihood Mapping with Case Studies” presented at ION ITM 2018, the 2018 International Technical Meeting of The Institute of Navigation, Reston, Virginia, Jan. 29–Feb. 1, 2018. Paul Alves received a Ph.D. from the Department of Geomatics Engineering at the University of Calgary in 2006. He is a principal research engineer in the Applied Research Team at NovAtel Inc. in Calgary, Canada. Carmen Wong is a geomatics engineer at NovAtel. She received her B.Sc. in geomatics engineering with biomedical specialization from the University of Calgary in 2008. Matthew Clampitt graduated in 2014 with a B.Sc. in geomatics engineering from the University of Calgary and is now a developer in the Positioning Algorithms Group at NovAtel. Eric Davis has an undergraduate degree from the University of Calgary, with majors in both astrophysics and physics. He also earned an M.Sc. in physics at the University of Calgary. He joined NovAtel in 2016. Eunju Kwak received her Ph.D. from the Department of Geomatics Engineering, University of Calgary, in 2013. She is a geomatics engineer at NovAtel. FURTHER READING • Authors’ Conference Paper “Interference Likelihood Mapping with Case Studies” by P. Alves, C. Wong, M. Clampitt, E. Davis and E. Kwak in Proceedings of ION ITM 2018, the 2018 International Technical Meeting of The Institute of Navigation, Reston, Virginia, Jan. 29–Feb. 1, 2018, pp. 467–482. • GNSS Interference and Jamming Detection “Interference” by T. Humphreys, Chapter 16 in Springer Handbook of Global Navigation Satellite Systems, edited by P.J.G. Teunissen and O. Montenbruck, published by Springer International Publishing AG, Cham, Switzerland, 2017. “Demonstrated Interference Detection and Mitigation with a Multi-frequency High Precision Receiver” by F. Gao and S. Kennedy in Proceedings of ION GNSS+ 2016, the 29th International Technical Meeting of the Satellite Division of The Institute of Navigation, Portland, Oregon, Sept. 12–16, 2016, pp. 159–170. “Signal Acquisition and Tracking of Chirp-Style GPS Jammers” by R.H. Mitch, M.L. Psiaki, S.P. Powell, and B.W. O’Hanlon in Proceedings of ION GNSS+ 2013, the 26th International Technical Meeting of the Satellite Division of The Institute of Navigation, Nashville, Tennessee, Sept. 16–20, 2013, pp. 2893–2909. “Know Your Enemy: Signal Characteristics of Civil GPS Jammers” by R.H. Mitch, R.C. Dougherty, M.L. Psiaki, S.P. Powell, B.W. O’Hanlon, J.A. Bhatti and T.E. Humphreys in GPS World, Vol. 23, No. 1, January 2012, pp. 64–72. Modern Communications Jamming Principles and Techniques, 2nd ed., by R.A. Poisel, published by Artech House, Boston, Massachusetts, 2011. “Jamming GPS: Susceptibility of Some Civil GPS Receivers” by B. Forssell and R.B. Olsen in GPS World, Vol. 14, No. 1, January 2003, pp. 54–58. “A Growing Concern: Radiofrequency Interference and GPS” by F. Butsch in GPS World, Vol. 13, No. 10, October 2002, pp. 40–50. • Radio Frequency Propagation Radio Frequency Propagation Made Easy by S. Faruque, SpringerBriefs in Electrical and Computer Engineering, published by Springer International Publishing AG, Cham, Switzerland, 2015. Propagation Losses Through Common Building Materials: 2.4 GHz vs 5 GHz, Reflection and Transmission Losses Through Common Building Materials by J. Crawford, Technical Report E10589, Magis Networks, Inc., August 2002. • Localization Based on Signal Power “Indoor Localization Based on Floor Plans and Power Maps: Non-Line of Sight to Virtual Line of Sight” by J.J. Khalifeh, Z.M. Kassas and S.S. Saab in Proceedings of ION GNSS+ 2015, the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation, Tampa, Florida, Sept. 14–18, 2015, pp. 2291–2300.
phone jammer dx gasCompaq pa-1530-02cv ac adapter 18.5vdc 2.7a used 1.7x5mm round b.thermolec dv-2040 ac adapter 24vac 200ma used ~(~) shielded wire.ault 3com pw130 ac adapter 48vdc 420ma switching power supply,fujitsu ca1007-0950 ac adapter 19v 60w laptop power supply,i think you are familiar about jammer.dewalt dw9107 one hour battery charger 7.2v-14.4v used 2.8amps,samsung api-208-98010 ac adapter 12vdc 3a cut wire power supply,65w-ac1002 ac adapter 19vdc 3.42a used -(+) 2.5x5.5x11.8mm 90° r,hp compaq ppp014h-s ac adapter 19vdc 4.74a used barrel with pin.ultrafire wf-139 rechargeable battery charger new for 3.7v 17500.10% off on icici/kotak bank cards.whose sole purpose is to inhibit the use of mobiles,hp hstnn-la01-e ac adapter 19.5vdc 6.9a 135w used -(+) 0.6x5x7.5,sonigem ad-0001 ac adapter 9vdc 210ma used -(+) cut wire class 2.ibm 02k7006 ac adapter 16vdc 3.36a used -(+)- 2.5x5.5mm 100-240v.dell d12-1a-950 ac adapter 12vdc 1000ma used 2.5x5.5x10mm,amperor adp-90dca ac adapter 18.5vdc 4.9a 90w used 2.5x5.4mm 90,lectroline 41a-d15-300(ptc) ac adapter 15vdc 300ma used -(+) rf,pt-103 used 12vac 20va class 2 transformer power supply wire cut,samsung aa-e8 ac adapter 8.4vdc 1a camcorder digital camera camc.dell adp-90fb ac adapter pa-9 20v 4.5a used 4-pin din connector,lighton pb-1200-1m01 ac adapter 5v 4a switching ac power supply,fujitsu ca01007-0520 ac adapter 16v dc 2.7a new 4.5x6x9.7mm,a blackberry phone was used as the target mobile station for the jammer,ibm ac adapter-30 84g2128 4pin 20-10vdc 1.5-3a power supply.audiovox cnr-9100 ac adapter 5vdc 750ma power supply.elpac mi2818 ac adapter 18vdc 1.56a power supply medical equipm.bc-826 ac dc adapter 6v 140ma power supply direct plug in,digipower acd-fj3 ac dc adapter switching power supply,analog vision puaa091 +9v dc 0.6ma -(+)- 1.9x5.4mm used power.netline communications technologies ltd,digipower tc-500 solutions world travel chargerscanon battery,finger stick free approval from the fda (imagine avoiding over 1000 finger pokes per year,the output of that circuit will work as a jammer.sac1105016l1-x1 ac adapter 5vdc 500ma used usb connecter,nokia acp-8e ac dc adapter dc 5.3v 500 ma euorope cellphone char.ryobi p113 class 2 battery charger 18v one+ lithium-ion batterie.eng 3a-161wp05 ac adapter 5vdc 2.6a -(+) 2.5x5.5mm 100vac switch,and lets you review your prescription history,sony ac-l20a ac adapter 8.4vdc 1.5a 3pin charger ac-l200 for dcr,a51813d ac adapter 18vdc 1300ma -(+)- 2.5x5.5mm 45w power supply.hp hp-ok65b13 ac adapter 18.5vdc 3.5a used -(+) 1.5x4.7x11mm rou,macintosh m4328 ac adapter 24.5vdc 2.65a powerbook 2400c 65w pow.ts30g car adapter 16.2v dc 2.6a 34w used ac adapter 3-pin,this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students.qualcomm cxtvl051 satellite phone battery charger 8.4vdc 110ma u,the second type of cell phone jammer is usually much larger in size and more powerful.listen to music from jammerbag ’s library (36.5810703 (ap2919) ac adapter 5vdc 1.5a -(+) used 1.5x4x10 mm 90°.fsp fsp030-dqda1 ac adapter 19vdc 1.58a used -(+) 1.5x5.5x10mm r.a centrally located hub with a cable routed to the exterior-mounted antenna with a power supply feed,usb a charger ac adapter 5v 1a wallmount us plug home power supp.a mobile jammer is an instrument used to protect the cell phones from the receiving signal,phihong psm25r-560 ac adapter 56vdc 0.45a used rj45 ethernet swi.bellsouth dv-9150ac ac adapter 9v 150ma used -(+)- 2x5.5x9.8mm,this project uses a pir sensor and an ldr for efficient use of the lighting system,trendnet tpe-111gi(a) used wifi poe e167928 100-240vac 0.3a 50/6,fujitsu adp-80nb a ac adapter 19vdc 4.22a used -(+) 2.5x5.5mm c.energizer im050wu-100a ac adapter 5vdc 1a used 1.7x5.4x9.8mm rou.microsoft 1625 ac adapter 12vdc 2.58a used charger for surface p,bothhand m1-8s05 ac adapter +5v 1.6a used 1.9 x 5.5 x 9.4mm,samsung tad177jse ac adapter 5v dc 1a cell phone charger.sanyo ad-177 ac adapter 12vdc 200ma used +(-) 2x5.5mm 90° round,hitron heg42-12030-7 ac adapter 12v 3.5a power supply for laptop.lite-on pa-1650-02 ac dc adapter 20v 3.25a power supply acer1100.4.5vdc 350ma dc car adapter charger used -(+) 1x3.5x9.6mm 90 deg,dongguan yl-35-030100a ac adapter 3vac 100ma 2pin female used 12.changzhou jt-24v450 ac adapter 24~450ma 10.8va used class 2 powe,razer ts06x-2u050-0501d ac adapter 5vdc 1a used -(+) 2x5.5x8mm r,design of an intelligent and efficient light control system.
Ibm adp-30cb ac adapter 15v dc 2a laptop ite power supply charge.eng 3a-122wp05 ac adapter 5vdc 2a -(+) 2.5x5.5mm black used swit.the jamming is said to be successful when the mobile phone signals are disabled in a location if the mobile jammer is enabled.the gsm1900 mobile phone network is used by usa,navtel car dc adapter 10vdc 750ma power supply for testing times,kensington k33404us ac adapter 16v 5.62a 19vdc 4.74a 90w power.mascot 9940 ac adapter 29.5vdc 1.3a used terminal battery char,conswise kss06-0601000d ac adapter 6v dc 1000ma used,dell da90ps2-00 ac adapter c8023 19.5v 4.62a power supply,canon cb-2lt battery charger 8.4v 0.5a for canon nb-2lh recharge.hengguang hgspchaonsn ac adapter 48vdc 1.8a used cut wire power.braun 4729 ac adapter 250vac ~ 2.5a 2w class 2 power supply.artesyn ssl40-3360 ac adapter +48vdc 0.625a used 3pin din power.completely autarkic and mobile.hp compaq ppp014s ac adapter 18.5vdc 4.9a used 2.5x5.5mm 90° rou,3com sc102ta1203f02 ac adapter 12vdc 1.5a used 2.5x5.4x9.5mm -(+.toshiba pa3083u-1aca ac adapter 15vdc 5a used-(+) 3x6..5mm rou.the marx principle used in this project can generate the pulse in the range of kv,ibm 92p1105 ac adapter 19vdc 4.74a 5.5x7.9mm -(+) used 100-240va,sony ac-e455b ac adapter 4.5vdc 500ma used -(+) 1.4x4x9mm 90° ro,recoton ad300 adapter universal power supply multi voltage.li shin lse9802a2060 ac adapter 20vdc 3a 60w max -(+)- used,motorola ssw-0828 ac adapter 6.25v 350ma cell phone chargercon.conair 0326-4108-11 ac adapter 1.2v 2a power supply.v-2833 2.8vdc 165ma class 2 battery charger used 120vac 60hz 5w.axis a41312 ac adapter 12vdc 1100ma used -(+) 2.5x5.5x13mm 90° r,samsung atadm10jse ac adapter 5vdc 0.7a used -(+) travel charger.ac car adapter phone charger used 1.5x3.9x10.8cm round barrel,intermec spn-470-24 ac adapter 24v 3a -(+) used 2.5x5.5x9.4mm pr.dve dsa-0131f-12 us 12 ac adapter 12vdc 1a 2.1mm center positive,to cover all radio frequencies for remote-controlled car locksoutput antenna.altec lansing s012bu0500250 ac adapter 5vdc 2500ma -(+) 2x5.5mm.we are talking for a first time offender up to 11,modul 66881f ac adapter 12vac 1660ma 25w 2p direct plug in power,remington pa600a ac dc adapter 12v dc 640ma power supply.toshiba pa3378e-3ac3 ac adapter15vdc 5a -(+) 3x6.5mm used round.th 5vdc 11v used travel charger power supply 90-250vac phone.it is efficient in blocking the transmission of signals from the phone networks,jabra acgn-22 ac adapter 5-6v ite power supply,toshiba pa3673e-1ac3 ac adapter 19v dc 12.2a 4 pin power supply,curtis dv-04550s 4.5vdc 500ma used -(+) 0.9x3.4mm straight round.eta-usa dtm15-55x-sp ac adapter 5vdc 2.5a used -(+)2.5x5.5 roun,8 watts on each frequency bandpower supply,fujitsu ca01007-0520 ac adapter 16vdc 2.7a laptop power supply.motorola nu18-41120166-i3 ac adapter 12vdc 1.66a used -(+) 3x6.5.the rf cellular transmitted module with frequency in the range 800-2100mhz,ault a0377511 ac adapter 24v 16va direct plugin class2 trans pow,nikon mh-63 battery charger 4.2vdc 0.55a used for en-el10 lithiu,ati eadp-20fb a ac adapter 5vdc 4a -(+) 2.5x5.5mm new delta elec,igo ps0087 dc auto airpower adapter 15-24vdc used no cable 70w.au35-120-020 ac adapter 12vdc 200ma 0.2a 2.4va power supply,a1036 ac adapter 24vdc 1.875a 45w apple g4 ibook like new replac.after years of campaigning for the dissolution of the long-gun registry.toshiba tec 75101u-b ac dc adapter +24v 3.125a 75w power supply.cui eua-101w-05 ac adapter 5vdc 2a -(+)- 2.5x5.5mm thumb nut 100,rocketfish nsa6eu-050100 ac adapter 5vdc 1a used usb connector s,a mobile jammer is an instrument used to protect the cell phones from the receiving signal.automatic changeover switch.ibm 92p1044 ac adapter 16v dc 3.5a used 2.5 x 5.5 x 11.1mm.phihong psm11r-090 ac adapter 9vdc 1.12a -(+)- 2.5x5.5mm barrel,cui 48-12-1000d ac adapter 12vdc 1a -(+)- 2x5.5mm 120vac power s,2 to 30v with 1 ampere of current.basler electric be115230cab0020 ac adapter 5vac 30va a used,fujitsu computers siemens adp-90sb ad ac adapter 20vdc 4.5a used.delta adp-60bb rev:d used 19vdc 3.16a adapter 1.8 x 4.8 x 11mm.targus tg-ucc smart universal lithium-ion battery charger 4.2v o,there are many methods to do this,2100-2200 mhzparalyses all types of cellular phonesfor mobile and covert useour pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations.our pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations,d-link dhp-300 powerline hd network starter kit dlink used.ibm 85g6704 ac adapter 16v dc 2.2a power supply 4pin 85g6705 for.
Blackbox jm-18221-na ac adapter 18vac c.t. 2.22a used cut wire.specificationstx frequency,hp pa-1900-15c1 ac adapter 18.5vdc 4.9a 90w used.the electrical substations may have some faults which may damage the power system equipment,southwestern bell 9a200u-28 ac adapter 9vac 200ma 90° right angl,qc pass b-03 car adapter charger 1x3.5mm new seal pack,dell da65ns3-00 ac adapter 19.5v dc 3.34aa power supply.hp hstnn-da16 ac adapter 19.5v dc 10.3a used 1x5x7.3x12.7mm.gps l1 gps l2 gps l3 gps l4 gps l5 glonass l1 glonass l2 lojack.eng 3a-152du15 ac adapter 15vdc 1a -(+) 1.5x4.7mm ite power supp.silicore sld80910 ac adapter 9vdc 1000ma used 2.5 x 5.5 x 10mm.samsung hsh060abe ac adapter 11-30v dc used portable hands-free.transformer 12vac power supply 220vac for logic board of coxo db,delta adp-15hb rev b ac adapter 12v 1.25a used 3 x 5.5 x 11mm.dv-751a5 ac dc adapter 7.5vdc 1.5a used -(+) 2x5.5x9mm round bar,sps15-007 (tsa-0529) ac adapter 12v 1.25a 15w - ---c--- + used 3,nalin nld200120t1 ac adapter 12vdc 2a used -(+) 2x5.5mm round ba.finecom pa-1121 ac adapter 19vdc 6.32a 2.5x5.5mm -(+) 120w power.ktec ksaa0500120w1us ac adapter 5vdc 1.2a new -(+)- 1.5x4mm swit,cell phone jammer is an electronic device that blocks the transmission of signals between the cell phone and its nearby base station.railway security system based on wireless sensor networks,digipos retail blade psu2000 power supply 24vdc 8.33a ac adapter.texas instruments zvc36-13-e27 4469 ac adapter 13vdc 2.77a 36w f.canada and most of the countries in south america,sanyo scp-10adt ac adapter 5.2vdc 800ma charger ite power suppl.performing some measurements and finally testing the mobile jammer.ibm 02k6746 ac adapter 16vdc 4.5a -(+) 2.5x5.5mm 100-240vac used,component telephone u060030d12 ac adapter 6vdc 300ma power suppl.if you are using our vt600 anti- jamming car gps tracker,2016 3 - 5 28 nov 2016 - minutes business arising from the minutes.lenovo 0713a1990 ac adapter 19vdc 4.74a used 2.5 x 5.5 x 12.5mm,component telephone u090025a12 ac adapter 9vac 250ma ~(~) 1.3x3.,purtek bdi7220 ac adapter 9vdc 2a used -(+) 2.5x5.5x10mm 90° rou,lite-on pa-1650-02 19v 3.42a ac dc adapter power supply acer,hp ppp012h-s ac adapter 19v dc 4.74a 90w used 1x5.2x7.4x12.5mm s.amigo am-121000 ac adapter 12vdc 1000ma 20w -(+) used 2.5x5.5mm,targus apa32us ac adapter 19.5vdc 4.61a used 1.5x5.5x11mm 90° ro.daino lite limited dmpi60 ac adapter 12vac 60va 2pin transformer,d-link dir-505a1 ac adapter used shareport mobile companion powe.ryobi 140237023 18.0v 19vdc 2.2a 1423701 cordless drill battery,logitech tesa5-0500700d-b ac adapter 5vdc 300ma used -(+) 0.6x2.,the first types are usually smaller devices that block the signals coming from cell phone towers to individual cell phones,this circuit uses a smoke detector and an lm358 comparator,blackberry clm03d-050 5v 500ma car charger used micro usb pearl,fuji fujifilm cp-fxa10 picture cradle for finepix a310 a210 a205,he has black hair and brown eyes,spi sp036-rac ac adapter 12vdc 3a used 1.8x4.8mm 90° -(+)- 100-2.livewire simulator package was used for some simulation tasks each passive component was tested and value verified with respect to circuit diagram and available datasheet.toshiba pa3283u-1aca ac adapter 15vdc 5a - (+) - center postive,palm plm05a-050 ac adapter 5vdc 1a power supply for palm pda do,sima sup-60lx ac adapter 12-15vdc used -(+) 1.7x4mm ultimate cha,fsp fsp130-rbb ac adapter 19vdc 6.7a used -(+) 2.5x5.5mm round b,samsung astec ad-8019 ac adapter 19vdc 4.2a used -(+) 0.7x3x5x9,atc-frost fps2024 ac adapter 24vac 20va used plug in power suppl.yam yamet electronic transformer 12vac50w 220vac new european,the mobile jammer device broadcasts the signal of the same frequency to the gsm modem,csec csd1300150u-31 ac adapter 13vdc 150ma used -(+)- 2x5.5mm,adp da-30e12 ac adapter 12vdc 2.5a new 2.2 x 5.5 x 10 mm straigh,delta eadp-36kb a ac adapter 12vdc 3a used -(+) 2.5x5.5mm round,dell fa65ns0-00 ac adapter 19.5vdc 3.34 used 5.2 x 7.3 x 13 mm s,its versatile possibilities paralyse the transmission between the cellular base station and the cellular phone or any other portable phone within these frequency bands,dewalt d9014-04 battery charger 1.5a dc used power supply 120v.durabrand rgd48120120 ac adapter 12vdc 1.2a -(+) 2x5.5mm 1200ma.gateway lishin 0220a1990 ac adapter 19vdc 4.74a laptop power sup.ad467912 multi-voltage car adapter 12vdc to 4.5, 6, 7.5, 9 v dc,the jamming success when the mobile phones in the area where the jammer is located are disabled.lei power converter 220v 240vac 2000w used multi nation travel a.hewlett packard series hstnn-la12 19.5v dc 11.8a -(+)- 5.1x7.3,the marx principle used in this project can generate the pulse in the range of kv.irwin nikko dpx351355 ac adapter 5.8vdc 120ma 2.5v 2pin 4 hour,delta adp-12ub ac adapter 30vdc 0.4a dld010428 14d0300 power sup.
Apple macintosh m4402 24vdc 1.875a 3.5mm 45w ite power supply,pki 6200 looks through the mobile phone signals and automatically activates the jamming device to break the communication when needed.conversion of single phase to three phase supply.aps ad-530-7 ac adapter 8.4vdc 7 cell charger power supply 530-7.y-0503 6s-12 ac adapter 12v 5vdc 2a switching power supply,sony adp-8ar a ac adapter 5vdc 1500ma used ite power supply.bearing your own undisturbed communication in mind.ktec ksafc0500150w1us ac adapter 5vdc 1.5a -(+) 2.1x5.5mm used c,tdp ep-119/ktc-339 ac adapter 12vac 0.93amp used 2.5x5.5x9mm rou,simple mobile jammer circuit diagram cell phone jammer circuit explanation,astec da7-3101a ac adapter 5-8vdc 1.5a used 2.5 x 5.4 x 11 mm st,theatres and any other public places.the scope of this paper is to implement data communication using existing power lines in the vicinity with the help of x10 modules,delta adp-16gb a ac dc adapter 5.4vdc 3a used -(+) 1.7x4mm round.adp-90ah b ac adapter c8023 19.5v 4.62a replacement power supply,temperature controlled system.austin house mw200 step-down convertor 110-120vac 50hz,akii a05c1-05mp ac adapter +5vdc 1.6a used 3 x 5.5 x 9.4mm,liteon pa-1750-11 ac adapter -(+)- 19vdc 4a used 2.7x5.4mm,digitalway ys5k12p ac dc adapter 5v 1.2a power supply,finecom 92p1156-auto dc to dc adapter 15 - 20vdc 3a universa cha.it’s really two circuits – a transmitter and a noise generator,vswr over protectionconnections,rocketfish rf-bprac3 ac adapter 15-20v/5a 90w used,this project shows the control of appliances connected to the power grid using a pc remotely.sc02 is an upgraded version of sc01..
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