Questions on a set of equipment used to generate and transmit electromagnetic waves carrying messages or signals, esp. those of radio or television.

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0answers
35 views

Can't transmit a BPSK modulated signal

I'm currently working on a BPSK transmitter and receiver. The problem is I don't know what I am missing and can't transmit/receive a data. My supply is 12v and -12v. So I'm trying to send a varying ...
-1
votes
1answer
71 views

Creating a home made ultrasound transducer

I don't know how ultrasound transducers (transmitters) are made, is it possible to create a home made ultrasound transmitter with a custom specific range 1MHz or more? If it is not, would a 3D ...
0
votes
0answers
36 views

Form of the received signal in a MIMO communication

I am reading an article which is related to MIMO communication networks. Consider that there are \$U\$ users, each of them have \$J_{u}, u=1,...U\$, different layers. We want to calculate the received ...
0
votes
3answers
106 views

There is a missing component in this circuit and couldn't figure out why?

I'm designing a BA1404 Stereo FM transmitter and I found the following source: Source Link You can find the component list, circuit scheme and the other stuff on this page. But when I look at the ...
0
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0answers
17 views

arduino manchester encoding two receivers [migrated]

I want to make the arduino receive from two receivers. I am trying to make another pin receive signals from another connected receiver in the pseudo code below, how can this be done?: ...
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votes
1answer
34 views

My Rf reciever circuit on battery ,but not with a rectified xformer output as source

I just made a Rf circuit that turns on and off a relay depending on the transmitter's message The circuit is working fine when i connect it to a 9v battery. But i cant get the circuit to work with ...
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0answers
15 views

Using RFM69W with Arduino Uno R3 [migrated]

I am quite new to Arduino and have been trying to build a home automation for my home. I want to know if anyone has used RFM69W with arduino Uno R3 successfully. After browsing through the various ...
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votes
1answer
25 views

Will BA1404 circuit work with TEA5591A

For an electronics project I would like to build stereo FM transmitter and receiver circuits. I was just wondering if these two circuits would work together. The BA1404 circuit can be found here. ...
0
votes
2answers
204 views

2.4 GHz versus 434 MHz transceiver for home automation

I am working on a project that uses an Arduino Uno R3 and will have one receiver and one transmitter. I'm going to use this for home automation within my home in India. I want to know which ...
0
votes
0answers
34 views

WS-RX-02 Receiver Range in Arduino

I have been preparing the receiver using WS-RX-02 receiver and arduino Uno R3 board. My connections are as follows. 3 GND PINS on RECEIVE UNITS are Connected to GND of ARDUINO 2 VCC PINS on RECEIVER ...
0
votes
0answers
61 views

Useing RC Switch Library for Transmitter and receiver in arduino

I have a RF remote and want to replace this with Arduino using RC Switch library. I want to sniff the codes from existing remote and send using RC Switch library in arduino. Is there any tool ...
0
votes
2answers
85 views

Best way to wirelessly transmit and receive data

I'm working on a project that requires wireless transmission and reception of data. I wonder what the best technology would be. It is not tons of data maybe not even a kilobyte. And the range should ...
0
votes
1answer
140 views

FM Radio transmitter and receiver circuits

I'm planning on building a FM transmitter and receiver circuit for an electronics project. I was just wondering if these two circuits would work together. Also would they be suitable for transmitting ...
1
vote
1answer
56 views

Connecting dipole antenna for transmission

I have a small FM transmitter on a breakout, the antenna is a single connection. It came with a thin blue wire for this purpose; below it spirals up and out the top of the photo. This works fine ...
0
votes
1answer
154 views

Generating Rolling Code with Arduino for RF Switch

I am working home automation using Arduino and TX/RX module. From various sources I learned that Rolling Code based RF Switches are having better security. I have following queries How suitable it ...
0
votes
0answers
54 views

RF Receiver sniff encryption

I am trying to build a home automation system using Arduino Uno R3 and transmitter and receiver module. I will be buying a RF remote switch. RF remote switch specification says it uses pairing coding ...
1
vote
1answer
95 views

Help with a RF reciever circuit

Recently I have been working on a basic RF receiver, but my efforts so far have proved fruitless. I designed the following circuit based of of previous research into the topic. According to what I ...
2
votes
1answer
115 views

A question about resonance and crystal radio?

This is a circuit of crystal radio transmitter. I've tested it, and it works properly. but I can't understand everything in this circuit... L1 and C5 make resonance frequency, Would you tell me if ...
1
vote
1answer
118 views

Basic FM circuit

I have been messing around with a basic FM transmitter circuit, and I want to have a better explanation on how it works. I have searched around and found nothing. Can someone please explain how the LC ...
0
votes
1answer
57 views

FM Transmitter Amplifier — Maximum output power with non-customized parts?

I would like to build an FM transmitter on my own and I found a nice circuit that acts as a USB sound card to transmit low power FM signals. http://tipok.org.ua/node/35 My plan is to add another ...
7
votes
7answers
320 views

Measuring direction of object (or angle of signal origin)

I am interested in somehow tracking the "compass" direction of a moving object from a reference-station -- in other words, something similar to submarine sonar systems (although I'm unsure how those ...
1
vote
2answers
110 views

How can I turn pulsating DC (square wave) from a 555 IC timer into an ac square wave?

I am trying to create build a morse code transmitter. I know that morse code is sent at 500 KHZ so I set my 555 to spit out pulsating DC in a square wave with 9 volt peaks. But I am unsure wether ...
8
votes
7answers
2k views

Schematics for a simple radio transmitter that can be built only with passive components?

Fantasized in some of the survivalist, post-catastrophic novels, movies or docudramas is the radio built only with handcrafted or scraped components. Beyond the popular appeal of this stories, I ...
4
votes
1answer
560 views

Data over a 5V DC power connector

I am looking for a simple way to encode some data over a dc power line. (Probably using a very low cost IC) In my design, I have a port that provides 5V, 200mA for connecting some device, but now I ...
1
vote
2answers
48 views

Could transmit/receive turnaround be improved by having a heterodyne receiver switchable between high-side and low-side injection

In some of the small radios I've worked with such as the Nordic Semiconductor 24LE line, there is a significant (100us+) delay between transmitting data and being able to receive a response. By my ...
0
votes
0answers
98 views

PIC16C54 used as signal generator from 100 KHz to 180 MHz

I have a PIC16C54 used as a DDS which generates 100 KHz to 180 MHz sine waves, model #80-035 datakit , I need source code but company is out of business. I purchased this as the early model called ...
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votes
1answer
80 views

Separate antenna for radio transmitter and receiver

I am building a HAM radio. Do I need a separate antenna for transmitter and receiver? I will be using 20m band and voice communication (No Morse code). My primary requirement is that I should be able ...
2
votes
1answer
171 views

How do I sniff this RF Transmitter Gate Opener Circuit?

What piece of hardware am I looking for to observe the transmitted radio signal? Would an oscilloscope come in handy here? is this a 2-channel RF remote, a 3channel RF remote, or something else? My ...
1
vote
4answers
112 views

How do multiple transmitters and single reciever work?

I have multiple digital transmitters sending packets to an receiver, and packets from different transmitters may arrive at the same time, how can the receiver differentiate multiple packets at the ...
1
vote
0answers
1k views

Audio + Video Transmitter + Reciever With 5 - 10 KM Range Circuit Diagram [closed]

I'm looking for a circuit diagram for a audio (doesn't have to be stereo) with video transmitter and reciever that has a range of more that 5 kilometers. I don't really have any limits on power ...
1
vote
3answers
153 views

Radio frequency signal transmitter

I lost the remote of an RC helicopter. I want to make a remote and know about the circuit. I am searching for this component which has three legs beside the LED in the pic. Would someone help me ...
1
vote
1answer
164 views

How to find out what radio frequency is being emitted?

Let's say I have something akin to a garage door clicker. How can I discover the frequency and message it sends with no other information on the device? I want to decode this to the electrical ...
0
votes
1answer
137 views

Need a help with 3D Low Frequency Wakeup Receiver AS3933

I am software developer and I am totally new to circuits field. Can somebody help me to understand how the 125 kHz transmitter and AS3933 receiver works? This is the link where it says how it ...
1
vote
0answers
134 views

How to switch a transistor when a radio signal is received?

I have a circuit which switches on by sending current to the base of one of its transistors. I'm trying to make receiver which can receive signals from a AM transmitter and send current to base of ...
0
votes
1answer
86 views

Can we capture and reproduce the bluetooth signals

Are there any devices that can capture bluetooth signals and reproduce them? Or is it simply possible to capture bluetooth signals if we have any bluetooth device? Does a bluetooth device have ...
0
votes
1answer
766 views

Power LED's using RF transmitter and receiver with Arduino

I'm working on a project that I have two sensors, two Arduinos (a YUN and an UNO), two LED's, and an RF transmitter/receiver It's a pretty simple procedure: Activate a force sensor, send it via RF ...
2
votes
1answer
234 views

How does a cube sat communicate with ground station with a 1w antenna

I heard that cubesat signals can be received with a hand held radio. Its confusing me that how a 1 metre antenna radiating 1watt energy can simply be received using hand held radios. I am designing a ...
1
vote
1answer
80 views

Can I estimate Wi-Fi's power transmission in function of the amount of data transmitted?

For a specific device connected to specific AP. Can I estimate the differences in radiation power (mWh) depending on the data transmitted (2KB/s vs 200KB/s)? If so, how?
1
vote
2answers
176 views

Hardware advice for simple wireless embedded application

Now, I am going to learn embedded programming in microcontroller. I am going to create a device that will receive signal from wireless transmitter. The range will be less than 30 meters. So, I have ...
1
vote
0answers
97 views

Bluetooth receiver from multiple transmitters

I need a bluetooth receiver to receive a signal from few transmitters. There is extremely little information about bluetooth on the internet. Google gives a lot of topics about android and iPhones, ...
0
votes
3answers
179 views

Linear potentiometer for suspension travel

I am working on a project for university measuring the extension of a cars suspension. I have a potentiometer available to me, but have a few questions regarding how to use it. I understand that it ...
1
vote
1answer
233 views

Using RF Link Transmitter/Receiver - ADC vs Microcontroller?

I have a sensor that gives off 4 volts when actuated and I would like to transmit it a distance to a light. So I found these RF Link Transmitter/Receiver at 434MHz: ...
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votes
1answer
452 views

FM transmitter main output frequency

please tell me the output frequency of this circuit,its work and has about 10 watt power with using C2101 as output stage,thanks It's working,and has high power in so far as I turn it on close to ...
0
votes
2answers
93 views

How to increase frequency modulation index?

I'm thinking of making a low power FM transmitter. Here's a diagram. It seems an absolute pull range of a VCXO will limit the modulation index. Is there possibly a way to extend it?
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votes
1answer
188 views

Trying to figure out the distance my computer is from my Bluetooth peripheral via RSSI. Is it possible?

I'm having a great deal of trouble figuring it out. I know it's far from exact, but I would like to have a reasonable estimate in meters. Right now my device is reporting back to my the RSSI value ...
0
votes
1answer
99 views

Can a smartphone transmit over the 902-928MHz bands? [closed]

I came across a remote control that uses the 902-928MHz band. Can a smartphone transmit WiFi/Bluetooth over those frequencies? If yes, is there anything special about it? Thanks
3
votes
2answers
148 views

Determining type of modulation

The circuit below is a radio transmitter circuit of a typical RC car. The circuit makes use of IC TX2 encoder. The output of IC ("SO" pin) is a series of pulses at low speed (84 Hz). This signal will ...
1
vote
2answers
113 views

Why is it so hard to get waves through the earth and ocean?

Quoted from the source Crystal sets to Sideband, the author said if you have an ohm meter measuring across the whole earth, the meter would display only 300 ohms. A while ago, I asked about earth ...
0
votes
1answer
371 views

UHF Transmitter - Arduino - How to

I am planning to do a near space balloon project with my son. I want to do something special. I don't want to just send up a camera I want to broadcast live video and other metrics. I have a strong ...
0
votes
1answer
453 views

Using 27MHz car with 49MHz remote control

I managed to do something like this guy here, but after I connected the Arduino to the 49MHz remote control, I figured out that I have another car which works on ...