Search for RF Signals in Topics


RF Generators

Just wanted to know if Function Generators were the same as RF Generators? I'm looking for a cheap RF for a project and when I put in "RF Generator" in eBay, it comes up with Function, Signal, and Linear Generators as well. Thanks.

Topic by FrenchCrawler    |  last reply


How can I reduce the signal range?

Any one know how to modify this so that you can adjust the range? Would simply adding a variable resistor to control the input voltage work? Or will I need an attenuator? If so, any ideas how?I would like to manipulate the existing range, not really extend it. https://www.instructables.com/id/Modifying-a-Cheap-Portable-Cellphone-Jammer/?

Question by zosim    |  last reply


Passive RF battery?

Hey i was just wondering what are typical conversion rates for signal to electricity in passive RFID tags? Information on the subject is usually not geared towards the electrical charge being generated.

Topic by Qcks    |  last reply


RF Module signal is too weak

Hello everyone! I am trying to build an arduino RF remote control to clone my remote control for my wireless sockets. I bought this RF module from ebay http://www.ebay.com/itm/New-433Mhz-RF-transmitter-module-and-receiver-link-kit-for-Arduino-ARM-MCU-WL-/140847542952?pt=LH_DefaultDomain_0&hash;=item20cb2af2a8 At first I thought it was damaged because I wasn't getting any signal from the reciever. After many tries I touched the reciever with the remote and suddenly I got the codes (I want to recieve the codes, save them and then re-transmit them with the arduino). The same goes with the transmitter - the only way it works is when I hold it against my wireless socket. It means that the codes work but the signal is way too weak. I tried hooking it up to different power sources- Arduino 5V, Arduino 3V, 12V 1000mA Adapter, and the original battery of the remote that states 12V 23A. I tried making an antenna but nothing really works.. please help! thank you..

Question by Tzabary    |  last reply


Low Gain in RF filter after the signal goes through the switch 2-18GHZ

Having trouble with an RF switch, getting low gain as it passes through the switch, I have x-ray the component, and all links are intact, no ESD damage that i can see, Does any one know what could be causing it to have low gain? possibly the RF track in the Switch? HEEELP?!?!!

Topic by SamuelG122  


Basic RF control transmission

My goal is to press a button on my transmitter side and have the receiver flip a relay - that's all.  It's probably the simplest possible use of RF technology...  and it's almost impossible to work out on google.  I am trying to transmit and receive just a simple control signal about a range of 300m, so dismantling 27Mhz toy cars is not an option.   Has anyone successfully made a simple RF circuit before? I can buy a 433Mhz transmitter with this range, but they take FSK or ASK modulated signals.  From what i can tell, there is nothing simpler than the 'OOK' version of ASK modulation for transmitting signals.  If I'm wrong, please correct me.  Otherwise, if I'm stuck with FSK or ASK.  I found one site (bottom of PDF: http://www.edn.com/contents/images/101101di.pdf) providing a simple circuit to produce FSK.  I was hoping for something simpler, but if you think this is the easiest way, i'll give it a shot. Can someone guide me towards the correct ICs and circuits to create this project? Thanks in advance for your help

Topic by trytrytryagain    |  last reply


I need a fairly easy 500 Mhz to 3 Ghz signal generator schematic

It needs to be fairly simple to make, my resources are a bit low again, and it doesn't have to generator a lot of different frequencies, just one or so within the range of 500 mhz - 3 ghz. Everything I found on line was either more complex then building a 40 meter transceiver, or was ready built and only cost $200 + Even if there was a source I could purchase, for under say $30, I would take that too. I need it to test my newest rig. I don't want to have to resort to something like this project here...

Topic by Goodhart    |  last reply


Better RF Mouse Range

Hello. I got a Wireless Mouse that still working fine.The signal between the Mouse and its receiver is not so great, about half meter, and it stop responding. So I took apart the Mouse and its Receiver. The antenna of the Mouse is kind of steal (I think but its color) and the one of the receiver is coil of very thing copper about 3/4 turns around a piece of plastic. So as said I would like to increase the signal between both, for better rang. What I have found around the best material is copper, so here is my issue. Is it better to modify the antenna of the Mouse or its receiver?? Should I rather use thicker Copper Wire and do few spinning around a piece of plastic, or use a thinner Copper Wire and do a lot of spin around a piece of plastic. So what better for a strong signal: - thicker wire and less spinning or - thinner Wire and more spinningThanx for those that would give a some advise/recommendations. I am will upload pictures later when possible. PS: I manage to add to it a Switch to turn off the mouse to extend battery Life.

Question by saadland    |  last reply


Decode Custom RF ASK Signal with Arduino & RadioHead

I have a remote that sends out a preamble, a pause and then a long code where a 0 is encoded as 100 and 1 is encoded as 110. I used an RTL-SDR to decoded the aforementioned ASK signal. I know the code is correct because I can simulate the signal using an Arduino and FS1000A. I simply connected the FS1000A's data pin to a digital pin and then I send out the signal. What I want to do is actually receiving the signal on the Arduino, i.e. which button was pressed on which remote (there are multiple remotes). For that I am using an XY-MK-5V and the Radiohead library. I used the RH_ASK driver sample code. However, it doesn't receive anything at all, meaning nothing is printed to the serial monitor.I think there are a couple of issues, i.e. it seem the Radiohead library expects a different preamble then what my remote sends and it also expects a checksum which my remote also doesn't seem to send. I haven't found a way to configure Radiohead so it can deal with my remote code. Is such a configuration possible. If not, what are the alternatives?

Topic by muludu  


How to make RF remote?

I was given a Clapper for my birthday... anyways, it came with a remote that uses Radio Frequency to turn on stuff. I want to know how to make my own circuit, any suggestions? I only want to control one thing, so the transmitter doesn't have to send too complex a signal and the receiver won't have to decipher much. All I need to know is HOW to send it. THANKS!

Topic by Login258    |  last reply


How to change a 433.92 MHz signal in to a 434 MHz signal?

Hi,I have these remote controlled wall outlets (Brennenstuhl Funkschalt-Set RCS 2044 N Comfort). And I'm trying to make an arduino circuit with an RF transmitter so I can switch them on and off without the remote.I sniffed the signal from the remote with an RTL-SDR and found out that the signal frequency is 434 MHz. So I went online and ordered an 434 MHz transmitter (from sparkfun).After I hooked the transmitter to my arduino and wrote the code with the exact same signals as the remote had send out. I tested the circuit and saw that it didn't work.So to see where it went wrong I also sniffed my signal from the RF transmitter, to see if it's the same as the one from the remote. And I found out that the frequency of my 434 MHz transmitter is actually 433.92 MHz.But this turned out that it wasn't a mistake. But the chip in the datasheet even says that it is 433.92 MHz. And when I went online to find a real 434 MHz transmitter I couldn't find one, because all the 434 MHz transmitters that I found were also actually 433.92 MHz.So then I tought how the hell has my remote a 434 MHz transmitter if I can't find one? And I screwed it open and saw in the casing that even the transmitter of the remote is 433.92 MHz. But for some reason it sends out a 434 MHz signal. So it must have some kind of circuit inside that modifies the 433.92 MHz to 434 MHz.And now my question to you is: How can I do that? How can I modify a 433.92 MHz signal to a 434 MHz signal?Thanks in advance!(I uploaded some pictures of the remote, the wall outlet, the RTL-SDR, the RTL-SDR captures on my laptop, The (simple) arduino circuit and the transmitter module)

Question by piet_lu    |  last reply


Why to use RF directional couplers in some measurements and control processes ?

I am an electronic engineer in the field of RF directional couplers, but I am puzzled about this question, why to use RF directional couplers in some measurements and control processes ? Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: RF radio frequency is referred to as RF current, it is a high frequency AC change electromagnetic wave short. Less than 1000 times per second changes in alternating current called low frequency current, more than 10000 times called high frequency current, and radio frequency is such a high frequency current. RF technology in the field of wireless communications with a wide range of irreplaceable role. In the electronics theory, the current flows through the conductor, the conductor will form a magnetic field around; alternating current through the conductor, the conductor will form an alternating electromagnetic field, known as electromagnetic waves. When the electromagnetic wave frequency is lower than 100khz, the electromagnetic wave will be absorbed by the surface, can not form an effective transmission, but the electromagnetic wave frequency is higher than 100khz, the electromagnetic wave can be spread in the air, and the outer edge of the ionospheric reflection, the formation of long-distance transmission capacity (Analog or digital) with high-frequency current modulation (amplitude modulation or FM), the formation of radio frequency signals, through the antenna to launch into the air, the radio frequency of the high-frequency electromagnetic waves.  Long-range radio frequency signal received after the anti-modulation, reduced to the electrical information source, this process is called wireless transmission. Wireless transmission developed for nearly two hundred years, forming a large number of users and product groups, but because of climate change and the impact of surface obstacles, can not transmit the perfect information. Modern human invention of the cheap high-frequency transmission cable (radio frequency line), in order to pursue the perfect quality of information transmission, taking into account the original wireless devices, wireless cable transmission began to pop. Resulting in the concept of radio frequency transmission. If your information source through the secondary modulation, with the cable to the opposite end, the opposite side with anti-modulation of the information source after the re-application, no matter how low frequency, but also radio frequency transmission, if there is no modulation anti-modulation process, The information source is transmitted directly to the opposite end of the cable, no matter how high the frequency, are the general cable transmission. SI --- Signal Integrity Signal Integrity PI --- Power Integrity Power Integrity emc --- electromagnetic compatibility Electromagnetic Compatibility rf - radio frequency RF emc = emi + ems EMI = Conduction + Radiation Emission SI: The Fourier transform shows that the higher the signal rises, the higher the amplitude of the higher harmonics. The MAXWELL equations see that these alternating harmonics produce alternating current at the adjacent line. And even through the space parasitic capacitance directly to another conductor, so these high harmonics is caused by radiation interference (emission) of the main factors; (that the simple point is that the signal rise faster, the more complete the signal, the better the signal quality, But for emi bad) . PI: PCB exists on the number \ \ analog area, high frequency \ 'low frequency region and other different areas and planes, if the partition is not easy to interfere with each other, that is, conduction conduction (conduction). Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of RF directional couplers. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.

Topic by maryzhu    |  last reply


RF remote Microcontroller etc?

So I found this remote control deal http://www.lightobject.com/1Ch-Remote-TX-Unit-IC-1527-C1-case-P385.aspx For the past few months I've bounced around the idea of using a hacked remote to turn the lights in my room on and off. This, however, makes hacking stuff a non issue. However, I still don't know how to make the remote communicate with a microcontroller. The one I linked appears to have an antenna, which is undesirable, but could become an option if nothing else. I also would like to see if I can find a similar control that uses infrared. Right, so, Basically I want a remote that sends a single signal to some kind of Microcontroller. When this signal is received, I want the microcontroller to emit a single pulse to toggle a latching relay to turn my lights on and off. Where should I look to find ideas or buy parts? I already have an Arduino, but I think I'd rather build a knockoff for a permanent circuit. So thanks in advance.

Question by mrmerino    |  last reply


high power RF analyzer using aurdino/raspberry pi?

Can  raspberry pi/ Aurdino board read RF signal of (5-6 GHz)  ? Is it possible to take  input through RF cables to raspberry pi/aurdino board? 

Question by arunrosh    |  last reply


How to send and receive an electrical signal?

I don't know much about radio waves and oscillator circuits , AM/FM and stuff, but I need to send just electrical signals wirelessly, without any information on it, to some other device which activates when it would detect the signals. I would prefer to make the devices myself, if it is possible, without needing to buy anything, like RF oscillators and other stuff.    I was told that whenever electricity passes through a wire, a radio wave is emitted outwards from the wire, and is emitted every time the current flow stops, starts or changes direction,  I was also told that whenever a radio wave crosses a wire, it induces a very small current in it. I don't know if whether the above information was correct or not but I think I can use it in making such a device.

Question by Wisaam    |  last reply


Schematics for a one way RF Relay/Switch?

So my plan is to have a small remote with a single pushbutton that when pressed will close a relay on the reciver, I would like it to have a pretty good range of at least 1000 Meters. I thought of using XBees and Arduinos but i only need the signal one way and only a single channel. Any ideas?

Topic by tomtortoise    |  last reply


The best way to boost an RF transmitter?

Hi all, Here I have a small and simple FM transmitter based on a simple transistor oscillator, however, due its simplicity, is weak for my needs: I need to transmit the signal to a distance of about 33 feet. Notice that I will use the transmitter in a rural location and around the building there are no other houses, so I will avoid the risk to cause interferences to other people. Well, so I was thinking to implement an amplification stage, after the transmitter, and I ended up with the following schematic: http://s23.postimg.org/5o8kycjrv/Oscillator_and_Amplifier.png On the base of Q1 I have a female jack where i get the audio signal from an MP3 player. However I have some doubts about resistors values for the amp stage: these values seems too much great to me: I get the Transistor values (BFR36) from the datasheet: http://www15.zippyshare.com/d/nmSyQm6e/625003/BFR36.pdf and I calculated the values here http://www.vk2zay.net/calculators/transistors/bjtBiasing.php (choosing "desing given emitter voltage") The power supply, as shown in the schematic will be equal to 12 V DC. But as I've said I'm not very convinced of resistors values for the amp stage, which seems too much greats. On the other hand, due to the fact that the amp stage is an emitter follower, it will just amplify the current and not the voltage: would be able to give a decent boost on the signal output? What I can expect? Thanks.

Question by akopelumenuscu    |  last reply


Rf motion sensor connected to USB receiver

I am JUST getting into home builds and i want someone that can help me or make one for me.. I want a motion sensor device that can send a signal to a USB receiver.. I then want the usb receiver to inturpert the signal and do something .. - like open or toggle a program on that computer... ultimately it would be a cubical boss alert device.. when it detects motion it automatically flips my application! :) Any takers? Ryan

Topic by rmwilson  


RF Radio Frequency Amplification RC Car with HMC478MP86E

I found rf amplifier up to 4.0ghz,it called HMC478MP86E right? My rc car use 2.4 ghz tx signal,on the datasheet,2.0 - 3.0 ghz the output is 16 dBm,the seller told me parallel it to make the output signal stronger. The question is what the dBm output after parallel? is it 32 dBm? its 1.4 W wow :D,is it right? sorry for my bad english :D fyi,im make fpv car so i can play it from house with the camera

Question by mismail15    |  last reply


Simple and CHEAP voting system - AM?

I'm a teacher, and I have a little (but not a lot) of money to spend. I'd really like to buy something like a Quizdom voting system, but with anything up to five classes of 26 running at once, it's just not financially possible. Which got me thunking... AM radio transmitters are cheap to build right? I've seen one using a 555 timer and an NPN transistor - these cost pennies - use to transmit voice. Could I instead transmit a BEEP - or high tone or something - each timer on a slightly different frequency? And have a single receiver which then listens across this frequency range and identifies which frequency is transmitting the tone or signal and feeds that back into... PC, Arduino, Raspberry Pi? Range would only need to be like 5-10m.

Topic by ohowson    |  last reply


Can I use a wifi amplifier for wireless video?

There are many wifi RF amplifiers that amplify wifi signals up to 5watts cheap on the internet, but no similar products for wireless video transmission. IF I purchased a low power wireless AV transmitter that operates on 2.4GHz, and combined it with the wifi amplifier, would it work? I see no reason as to why not, but I am not well versed in these things. long story short; can I plug an AV transmitter into a wifi amplifier to increase the power of the signal?

Question by cheeseboy    |  last reply


RF Transmitting Shock Alarm Clock

I thought of an idea awhile back but I lack the "know how" to pull it off. I've been trying to teach myself some basic electrical and computer engineering but i'm still not learning what i need to know in order to finish my project. as stated in the Title, i'm trying to build an alarm clock that wakes up its subject with a jolt of electricity rather then noise, vibrations or anything else. the concept is to incorporate a miniaturized TENS unit (Transcutaneous electrical nerve stimulation) http://en.wikipedia.org/wiki/Transcutaneous_electrical_nerve_stimulation into an arm band or ankle bracelet sort of thing but comfortable. then when it is time to wake up the alarm clock then sends a signal to the arm/ankle band thus making it active. then to turn it off you would hit the off switch on the alarm clock not the band.  that is the extent of my crude invention, however i am having trouble with the transmitting part. what would i need to make this happen?? i was thinking of using an old car remote for some of the parts and using the overall idea of it in my alarm clock except i need a transmitter and receiver and i have NO idea how any of that works. thoughts? ideas? please let me know

Question by fireball9919    |  last reply


How would one build a device that follows/is attracted towards a signal(IR, RF, etc.)? Answered

Hello, what is the simplest way to control a device so that it is drawn towards a certain point? I'm sure there is already an instructable on such a device but I can't seem to find it. Sound or voice control, line following, and light following(except maybe IR) won't work. Any guidance would be greatly appreciated. Thank you!

Question by mytleviathan    |  last reply


Can somebody help me with a 315Mhz RF module?

Hello everybody At the moment I'm building a circuit that should make a little motor turn forwards or backwards. It will be controlled by an 315Mhz RF module, wich i've bought from dx.com. The circuit contains: a voltage regulator, a H-bridge for the motor, and a reveiver. When i connected the circuit on a breadboard everything worked perfectly (even without an antenna connected I could control the motor over 20 meters away). Then I soldered everything in place, connected a 23,8cm antenna to the board and I placed the hole thing in a plastic container. Then the trouble came. I can only control the motor from 50 centimeters away, if i go futther the signal light will blink instead of a continuous light. Can anyone help me out?

Question by lukeD    |  last reply


Powering a device from radio waves?

I was just curious, but I was told someone was arrested fpr powering their house from a tv signal (illegal I know), but I was wondering if there would be any case where it would be legal to utilise my own RF signal as the source of power for some devices, and how is it possible?

Topic by MoonDemon  


Powering a device from radio waves?

I was just curious, but I was told someone was arrested fpr powering their house from a tv signal (illegal I know), but I was wondering if there would be any case where it would be legal to utilise my own RF signal as the source of power for some devices, and how is it possible?

Topic by MoonDemon    |  last reply


Powering a device from radio waves?

I was just curious, but I was told someone was arrested fpr powering their house from a tv signal (illegal I know), but I was wondering if there would be any case where it would be legal to utilise my own RF signal as the source of power for some devices, and how is it possible?

Topic by MoonDemon    |  last reply


how do you pick up the signal from the chest strap of an un-coded heart rate monitor?

I've got a Polar heart rate monitor, which includes a chest strap and a watch. The strap sends out an RF pulse for each heartbeat it detects. These pulses then get counted and then displayed by the watch on your wrist. I would like to be able to intercept this RF pulse and do my own thing with it. My initial idea is a treadmill-mounted device that displays the current heart rate and at least some sort of min/max display, indicating when you are in the ideal HR zone. I think I know how to build the device, but the first step of intercepting the pulses has got me stumped. Anybody know the specifications of the strap and how to get the signal? Thanks!

Question by dmeierhofer    |  last reply


fiber optic transmitter and reciever booster

I am a hobbist/inventor/sculptor/geek. I am looking for plans or a kit to build a fiber optic booster transmitter and reciever. Or even a unit that can send and recieve data and video signals. The signal must be able to travel a minimum of 300 ft. I am trying to build a submersible rov that I can afford. The other option that I might have is a rf to fiber optic converter. Would anyone be able to help me out?

Topic by batguanno  


GPS Repeater from a Hacked Wirelss Router?

Hi all. I'm building a GPS Repeater. I'm wondering if any one has ever tried to use the LNA on the Xmit side of a wireless router to amplify and re-radiate a GPS signal? I'm still in the research stage, but I'm thinking I can take the signal from a active GPS USB patch antenna, tie it into the LNA input on the RX side of a wireless router (hack all signals in the router- we are just interested in the power and signal input). Schematics to a router would be great. I have 10+ years in RF, so I know that the Xmit on a router is so not 1.5GHZ range like GPS. A few mods to some componets can ceratinly help turn the center freq of the Xmit. on the router.   What are your thoughts?

Topic by chris23892    |  last reply


I need to repeat radio frequency in the 402MHz range.

I need to repeat radio frequency in the 402MHz range.  How do you build a RF repeater? I need to extend the range of a CGM (Continuous Glucose Monitor). It uses the MICS protocol.  Can you adapt an existing device?

Topic by arourke1    |  last reply


How can I build a remote wall outlet that is controlled from the light switch?

Have you ever plugged a light into a wall and come to find out the light switch for that room isn't connected to that outlet? Well, I'm trying to figure out a way to make a device that plugs into the switched outlet and sends a signal to a receiver plugged into an outlet you want to be switched. That way you can turn on multiple lights in a room without running all sorts of extension cords. I don't know if you can use the existing power lines in the house to transfer a signal or if it has to be RF or something. Any ideas?

Question by Daday1974    |  last reply


How could I tell if someone installed a phone tap, camera, or voice recorder in my room?

When I leave for work, I sometimes leave my bedroom window open. There is a medium sized gap between the screen about the size of your fist. Is there a way I could tell if someone has tapped my house? Recently my Samsung Flat-Screen has been very snowy and I remember that you could tell is something has been tapped because they interfere with your tv. The house I just moved into also has a wire panel outside my window which you can reach. My room is first floor, please help. I cannot sleep. I also read that you can tell just if you can pick up RF signals coming from the device. Can someone give me a schematic for an RF Signal detector? I can't afford the commercial ones, I once read a stat that if you suddenly wake around 2am or 3am there is %80 chance of someone staring at you. Your body naturally senses this somehow. Well, when I looked at my window, I saw a light then after a few seconds it was gone. I went outside and I heard a couple of cans fall over and my fence my shaking like it was moved. My gate is usually locked but it is a reletively short fence. I haven't slept for days. I can't stand it. I'm going today to buy some black curtains as these cheap plastic blinds aren't cutting it

Question by halo99    |  last reply


Novice here. Send a "gate open" signal from indoors? A gate closes access to the driveway leading to my little guest house.

I’m completely new to making electronically operated devices. I can't interpret and translate the existing rf signaling instructables to my situation. I’m also completely new to your impressive Instructables.com. Happy to be here. The situation: On a shared property stands a main house and a little guest house. Both are served by a single driveway. Access to the driveway is restricted by a gate. The main residence (not mine) utilizes 1. a remote control and 2. a drive-up keypad to send the "gate open" signal. (Aside: the drive-up keypad is paired with an intercom. The intercom serves the main house only. My guests, or delivery drivers, must telephone me to alert me of their presence at the gate. To open the gate for them, I must exit my little guest house residence, walk the length of the property, aim my remote control, line-of-sight, at the gate and depress the button on the remote control. The gate opens. I make the return walk to the entrance of my residence. This poses two problems: 1. guests and delivery drivers must wait while I make the journey out of the house, to the end of the property and 2. I must make this journey through inclement weather and nighttime darkness. My first goal is to achieve an indoor located, or a just-outside-the-front-door located, "gate open" signal sending trigger. I've read that wired signal sending performs more reliably than wireless, due to the abundance of potentially interfering wireless device traffic. I dunno. My second goal is to give my guests and delivery drivers a two-way voice communication "intercom" specifically with persons in the guest house. This communication device must be unobtrusive in appearance to be appropriate-enough to stick onto the drive-up keypad & intercom to the main house. A device operating as communication to the guest house belongs alongside the intercom button to the main house. That's so my delivery drivers don't buzz the main house, unnecessarily bothering the owners. That has happened. Makes me cringe. There must be many methods by which to solve the two challenges: 1. a guest house located, “gate open” signal sender. The signal reliably reaching the end of the property and aiming at the gate, and 2. a guest house located, two-way voice communication something. I’ve seldom even peered into interiors of electronic devices, and am confessing my entire ignorance of electronic signaling. Since I embody the least informed and least experienced person possible to achieve these to goals, it seems to me the simplest to assemble and test is the best, and that I begin with challenge one. I appreciate you for your time in considering how best to recommend I proceed. I'm in the dark. If you are very swift of mind and short of time, perhaps take a pass on this one. I need a most elementary, every little step described, no steps missing or out of order, type of response. I’m a neurodivergent individual. I’m good with it. And I will convey, from within my areas of creative visual fluidity, instructables in gratitude for yours, and for fun. And when other Instructables.com participants request guidance that I can offer, I’ll do so.

Question by terrycten    |  last reply


Building blocks associated with Arduino 433 Mhz transmitter & receiver

Newbie here.  I want to make a temperature monitor that will transmit an alert signal to a receiver.  If I use the little 433Mhz  Arduino RF transmitter / receiver modules, what would I need with them?  I know these can be attached to the Arduino programing boards and are made functional by a computer program, but I don’t want to stick the Arduino program board & computer under the house where I want to measure the temperature.  I’m confused by this.  I understand these little units are used in remote control cars & planes, but what do they get connected to?

Question by ItsDavid001    |  last reply


Protection against EMP ...

Hi !Data :Let's say that I want to protect some important electronics devices against EMP.Let's say that they need to work 24/7 and that they are, thus, connected to an external source of power (electrical socket before EMP, and solar panel after EMP).Let's say that they need to emit and receive RF signals.Questions :1) As there are electrical connections with the exterior, a Faraday cage would be pointless, wouldn't it ?2) Would a solar panel survive to an EMP ?3) Is this possible to use the Faraday cage as an antenna for RF communication ? (I guess it's a stupid question as connecting the cage to the device would make the cage part of the device ...)4) Are thin and transparent gold foils enough to act as a Faraday cage ?_Edit : Interesting readings found thanks to the links Nachomahma provided :http://www.todaysengineer.org/2007/Sep/HEMP.asphttp://www.spectrum.ieee.org/archive/1543_Edit2 : an article about EMP protection.The first part is about EMP from nuclear bombs. The last part gives some clue about HMP.http://www.aussurvivalist.com/nuclear/empprotection.htm

Topic by chooseausername    |  last reply


Shock Collar activated by mobile phone call/text?

Hi,  I want to convert an electric shock collar to be activated by a call or text sent from my mobile phone. It has to operate long distance, so I assume some sort of stripped-down mobile device will be needed that can receive a mobile signal.  I have no idea how ot go about this, anybody have a solution for me? Does a device like this already exist, here or on the market?  I tried shopping about but could find no commercial device of this nature, only 'long range' RF shock collars with a maximum range of 1000 metres. 

Question by Ohnanka    |  last reply


how do i amplify the radiofrequency of my 40mhz remote control so it will operate my receiver from a further distance? Answered

as some of you may know now, i am building an r/c tank, it operates on a frequency of 40mhz. now i have a problem, the old remote controller i had for it which i modified (by accident), has been thrown away after it stopped working (thanks to my un-understanding mother) the problem with this is though that i when i changed it around (i swaped some parts to make it work with aa's instead of button cells) it worked at 100m, the remote i have now though wont operate the receiver at any distance above 40 meters, so i want to know, where can i get a rf booster that will work for my remote control, sort of a thing that can boost the signal as it goes though the antena, or something, ive seen something like it in jaycars catalogue, but it only works on frequencies between 50mhz-1ghz, and it extends the radio coverage by 100m. since its only a toy remote i dont think it can be alterd, plus this one isnt the same as the chip transmitter i used to own, this one is a crystal remote controller.

Question by oldmanbeefjerky    |  last reply


Need a very simple wireless two-way audio communication device.

Hello, i need  a simple wireless two-way audio device for communication within the house. i like to have a small device like a tiny headset, that is simple and has good range. i wish to make this really cheap, under 200 INR. mainly for audio communication (full duplex communication). here, where i live, i don't have access to any good technology. i mean, i cant even get simple "variable capacitor". so i have to purchase anything online, but the shipping rates itself to my place are too high for my budget. i have seen circuits like "fm transmitter" but i need a "fm reciever" to pickup that signal. but fm recievers are hard to build. i even made a fm transmitter( a very simple one), but it often switched the frequence, so i couldn't have a fixed frequency.  so i look for a circuit that is easy to tune and can be fixed frequency. i came across this module "433Mhz RF Transmitter Module + Receiver Module Link Kit for Arduino" but i done know anything about  arduino.  if i can use this module to make a two-way voice communication, please guide me how to. if not, please give me other ideas.

Question by jaga0692    |  last reply


How to answer my land phone from my Android smartphone using Bluetooth or Ethernet? Answered

Hello, guys! For academic purposes, I want to develop a solution so that I can answer my land phone directly from my smartphone when I'm at home close to the land phone, so, no Internet or other kind of long-distance communication here. Imagine a scenario where I'm at home, the land phone rings and I have the call information on my smarphone and I'm able to answer or reject it directly from my smartphone. I know the phone carriers offer services called "Follow me" that will redirect the call to my cell phone if it rings a few times and no one answers it, but, that's not what I mean. I want to answer the call on my smartphone as if it were an extension of the land phone. Two ideas came up to my mind, but I'm not sure I could make any of them work. 1- I thought of using some microcontroller like Arduino or something to hack the phone and somehow work as a bridge between the land phone and my smartphone via an Android application using bluetooth or a Wi-Fi ethernet connection. 2- I also thought of using a cordless phone base and capture the RF signals with my Arduino and make it route the call to my smartphone, so that it would ring when the land phone receives a call. If you guys think none of my thoughts would be viable, I would accept any kind of suggestions, even the most weird ones involving interconnection between multiple and heterogeneous devices, hardwares, softwares, technologies, etc. Thanks in advance!

Question by marciofl    |  last reply


Is it worth dropping $400 on a shiny new Rigol DS1054Z scope?

I will describe my situation: I am a hobbiest that likes to make cool projects, and plan to get into maybe RF analog stuff, (maybe start out with making a few FM bugs, reverse engineer a simple video transmitter kit, and a few other things.) as well get into arduino some more, AC analysis (learn about Xformers, power factor, maybe some math, etc.) and I so currently have an old 2ch. 30MHz analog oscilloscope that is a PITA to make real measurements with. Not only is it huge and takes up a lots of space, but also I'm not even sure it is in cal!) I will be transferring into UVA (or maybe VT) for EE, and gone this summer for a NASA internship at langley. (maybe I will be able to take it with me w/ a toolbox of some electronics stuff!)   The scope I am looking at (what appears to be what many subscribers seem to use, and/or claim is pretty good) is the Rigol DS1054Z. I only know how to use my $30 30MHz BKprecision scope I got on craigslist from the son of a father who was a TV repairman, and have NO experience with the use of the fancy-shmancy digital scope! What little I know is from watching EEVblog review of other scopes in the past. (I do know that they can be useful for 'capturing' waveforms, and can be set up to trigger on a pulse, maybe a certain digital codes, and that could come in handy for reverse engineering crap.)   https://www.youtube.com/watch?v=7v-tFYbc7h8   https://www.youtube.com/watch?v=W2qdtQkBKhc   https://www.youtube.com/watch?v=ETCOhzU1O5A   https://www.youtube.com/watch?v=-gStNYfqMXk     What sells it to me, being a complete newbie to electronics and digital scopes is that it has a nice big screen, the specs seem good (other certainly think, I have no intuition of what any of those things mean except the bandwidth, and maybe the sampling rate, 1GSa/s), 4 channels, intensity graded display, and it has loads of functions and stuff for me to grow into, and hacking it to make it think it is a DS1104Z is tempting, but I probably will not do that right away. Maybe once I feel what it offered is limiting.   The deal breakers is the $400 price, a bit steep for me (cheap for something this good, apparently but still.), the fear that by the time I really start using it, it will be obsolete and the same money can buy some quantum super duper ASIC tech whiz bang 3GHz 100Gsa/s 1GB segmented memory spectacular scope!   I am not really sure if it has a source, or signal generator either. Some sources claim that higher end ones do, or certain models anyway, and it seems like the official site say's no. http://www.rigolna.com/products/digital-oscilloscopes/ds1000Z/ds1054z/ That brings me to my next point. Should I also get a decent function generator?   

Question by -max-    |  last reply


Is it worth dropping $400 on a really nice oscilloscope (Rigol DS1054Z)?

I will describe my situation: I am a hobbiest that likes to make cool projects, and plan to get into maybe RF analog stuff, (maybe start out with making a few FM bugs, reverse engineer a simple video transmitter kit, and a few other things.) as well get into arduino some more, AC analysis (learn about Xformers, power factor, maybe some math, etc.) and I so currently have an old 2ch. 30MHz analog oscilloscope that is a PITA to make real measurements with. Not only is it huge and takes up a lots of space, but also I'm not even sure it is in cal!) I will be transferring into UVA (or maybe VT) for EE, and gone this summer for a NASA internship at langley. (maybe I will be able to take it with me w/ a toolbox of some electronics stuff!) The scope I am looking at (what appears to be what many subscribers seem to use, and/or claim is pretty good) is the Rigol DS1054Z. I only know how to use my $30 30MHz BKprecision scope I got on craigslist from the son of a father who was a TV repairman, and have NO experience with the use of the fancy-shmancy digital scope! What little I know is from watching EEVblog review of other scopes in the past. (I do know that they can be useful for 'capturing' waveforms, and can be set up to trigger on a pulse, maybe a certain digital codes, and that could come in handy for reverse engineering crap.) https://www.youtube.com/watch?v=7v-tFYbc7h8 https://www.youtube.com/watch?v=W2qdtQkBKhc https://www.youtube.com/watch?v=ETCOhzU1O5A https://www.youtube.com/watch?v=-gStNYfqMXk What sells it to me, being a complete newbie to electronics and digital scopes is that it has a nice big screen, the specs seem good (other certainly think, I have no intuition of what any of those things mean except the bandwidth, and maybe the sampling rate, 1GSa/s), 4 channels, intensity graded display, and it has loads of functions and stuff for me to grow into, and hacking it to make it think it is a DS1104Z is tempting, but I probably will not do that right away. Maybe once I feel what it offered is limiting. The deal breakers is the $400 price, a bit steep for me (cheap for something this good, apparently but still.), the fear that by the time I really start using it, it will be obsolete and the same money can buy some quantum super duper ASIC tech whiz bang 3GHz 100Gsa/s 1GB segmented memory spectacular scope! I am not really sure if it has a source, or signal generator either. Some sources claim that higher end ones do, or certain models anyway, and it seems like the official site say's no. http://www.rigolna.com/products/digital-oscilloscopes/ds1000Z/ds1054z/ That brings me to my next point. Should I also get a decent function generator? 

Question by -max-    |  last reply