Questions tagged [transmitter]

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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3
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2answers
692 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 ...
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2answers
13k views

Is it possible to use 2-way walkie talkie to locate position?

Basically, given no GPS is allowed, can we use walkie talkie to locate the position of a car / a person? I am assuming the walkie talkie is using radio, not GPS-based. What equipments will be ...
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2answers
118 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 ...
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1answer
2k 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 ...
11
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6answers
33k views

ultra low power mini wireless transmitter / receiver?

I'm looking for suggestions for a wireless transmitter & receiver combination. I'm basically just trying to bridge several buttons over a wireless signal(s) (i.e. send a 1 bit signal) in as small ...
2
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1answer
218 views

How to debug a transmitting configuration?

I'm using a CC1101 radio to communicate with an existing protocol. The settings I've used to configure the radio seem sound, as I'm able to receive messages from the 'other end' without errors. My ...
0
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1answer
2k 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 <...
2
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2answers
202 views

Wireless signal reflection

When two devices are connected via wireless, one device sends a character using its TX line, and the character is received by the other device on its RX line, and vice versa. My question is, RF ...
2
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2answers
1k views

Re-broadcasting a wideband satellite television signal over a short distance?

Normally a coax cable connects a satellite dish to the receiver. I'm in a situation where I can't easily install a coax cable, but a wireless signal ought to be possible because it's only 10 meters ...
4
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2answers
3k views

Wireless transmission/reception through 100 feet (30m), including concrete wall

I have an electrical engineering degree, but little experience in building wireless equipment. I need to transmit a signal through about 100 feet of distance, including a concrete wall. I need ...
2
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2answers
7k views

Using one RF transmitter to send an On/Off signal to multiple receivers

I want to create a system where I can send an On/Off signal to multiple receivers, to say, tell them to turn on an LED. Would I need to have a transmitter/receiver pair for each LED, or can I just ...
0
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1answer
80 views

Calculate transmitting power of the Transmitter

I cannot get a hold of my professor and I'm stuck tyring to understand how to solve this problem. It's not homework or an assignment I'm preparing my self for a test. So as the title states I need ...
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2answers
612 views
6
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2answers
9k views

Any wireless technology to find the distance between transmitter and receiver

I have a static transmitter and a mobile receiver. Is there any wireless technology to find the distance between the two in real time. Apart from using gps!
2
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3answers
262 views

High Powered Radio Transmitters

What kind of radio transmitter would be used on an data collection unit to transmit telemetry over long distances? For example a weather station in a remote location, or in a buoy just off the coast ...
5
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3answers
5k views

Does an RF receiver constantly consume power?

I'm building a battery operated robotic arm and would like to use a cheap, short distance RF transmitter/receiver kit to trigger it. However I would like to know whether the receiver will constantly ...
3
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2answers
801 views

Designing a Morse code transmit/receive shoe

Thank you for considering my general question, which I assure you is serious! I want to build -- or have built -- a magnificent shoe that can convert taps (front of the shoe) into Morse code and ...
-5
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1answer
1k views

Mapping Temperature Transmitter Range: 4-20 mA to temperature Range: 0-100C [closed]

I want to know as to how do you subdivide the above range 0 C To 100 C into 4 to 20 mA.? Each mA will be of what Range in degree C.
-1
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1answer
792 views

Question about transmitter/reciever

I have built a transmitter/receiver with an antenna and crystal. I am wondering if it is stable. Here is my transmitter: simulate this circuit – Schematic created using CircuitLab Here is my ...
0
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2answers
202 views

Checksum done without microcontroller

How could I transmit data from a device such as a distance sensor or quadrature encoder with an RF transmitter and also transmit a checksum or will I have to use a microcontroller such as the Arduino?
2
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2answers
3k views

Is there any circuit like “Burglar alarm ” or “Proximity dector” with a range of 100 meters

I am in search of a circuit which works with IR or RF wave with a range of 100 meter to detect proximity or burglar. I need this to detect the presence of human or animals One thing important is i ...
4
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1answer
889 views

How do I determine the proper FM transmitter strength?

I want to build an FM transmitter that will transmit (on an unused frequency) from my laptop (near my video projector) to my receiver (about 20' away on the other side of the room). Then, I thought ...
4
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1answer
1k views

FM Transmitter Circuit

I'm trying to make a FM transmitter work properly. I built the following circuit : I can synchronize with 94.8Mhz channel on any FM radio, I know that because the original sound from that radio is ...
6
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4answers
388 views

Digital Compass identifying direction of travel for use with trains

I work in a control center for a train company in the UK. Our trains work in either direction but only one end has first class carriages. Because trains on our network reverse quite a lot it is ...
1
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1answer
313 views

Spark Transmitter with flyback driver and good arcs

I recently built a Fly-back Driver with a fly-back transformer and a primary voltage input of 12 volts and the arcs are about an inch long ( i don't know the exact output voltage because I don't have ...
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2answers
1k views

Transmitting GPS data to Raspberry Pi

I am trying to figure out a way to get GPS data from a remote source to a Raspberry Pi. The remote source would be a helmet mounted GPS receiver so it would need to be small and preferably inexpensive....
0
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1answer
925 views

How to make a cw transmitter with a crystal oscillator (A0645147)?

I am trying to make a very basic cw transmitter, so far i got a 5V crystal oscillator: A0645147. Whenever I apply voltage to it i can pick up the signal on my handheld however i am not hearing the ...
1
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1answer
124 views

Power and decibels

In one of the examples in a engineering textbook, I noticed that the decibel value for the Power of a transmitter (also known as modulator) was 20DB and this was said to be equivalent to 100W. ...
1
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1answer
3k views

How to measure distance from moving object using RFID?

I want to make a project on an anti-collision system using RFID. I'm facing many problems selecting RF reader and tag: the required UHF generator, tags and reader are expensive. Any suggestions on ...
2
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1answer
255 views

Video Transmitter/Receiver Books&Schematics [closed]

I'm looking to build a video/audio or just video transmitter and receiver for use in robots. I'm primarily doing it as an excercise, but I'd love to be able to get a range of 100-200 meters. I'd love ...
5
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1answer
2k views

A complete Radio electronics guide

I want to learn all the basics about making a simple radio project. The project is simple... One transmitting device (which only sends out analog signals of some decent frequency.. say 50MHz) and one ...
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1answer
357 views

Dangers of building a radio transmitter?

As an educational project I am interested in building a radio transmitter (either AM or FM, probably AM to start) similar to the ones that you take in the car that can play your iPod. The car ...
3
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2answers
413 views

Product design requirements to pass FCC regulations

I've been spending a lot of time looking at 47 CRF 15, and specifically .231, and I don't understand how these limits are possible for many products. I'm designing a remote control for a product that ...
2
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1answer
8k views

How to calculate the range of a RC transmitter

When searching for a transmitter for a RC application in most of the cases they don't provide anything about the range of the module. Just power and the frequency. The Tx power must relate to the ...
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1answer
181 views

How do I troubleshoot a broken SAA3004 Remote control transmitter used in a remote control?

I'd like to troubleshoot and fix a broken remote control for a Guldmann ceiling lift that uses the SAA3004 remote control transmitter (documentation below in link). Can someone explain the tools ...
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2answers
122 views

How to polarize a signal before sending it to the antennae

I am an electronics noob and searched around the FAQ and this question seems askable. My questions are: How can I create polarized signals and are there any parts I need to be aware of to easily do ...
3
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1answer
346 views

Switching Mixers for LO frequency= 4.25Ghz

I want to upconvert a square pulse of 250 Mhz bandwidth(250Mhz is the value of the first zero of the sinc ) to a center frequency of 4.25 Ghz , so that the spread becomes from 4Ghz to 4.5 Ghz. ...
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2answers
4k views

How RF 443.92 MHz works?

I have an RF 443.92 MHz transmitter and the receiver, the model is TWS-DS-3 and I'm trying to understand how does it works. There are 4 pins (GND, Data In, Vcc, ANT), I'm going to wire the Vcc on a 5V ...
0
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1answer
345 views

Multiple micro solar power wireless transmitters / receivers operating in close proximity? SRDs

Hi I have a few questions about a Tx / Rx idea. Description Approximately 10 transmitters and 10 receivers are expected to work in close proximity of each other. However Rx1 only receives information ...
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1answer
613 views

FM bug Circuit Issue

I implemented this circuit stripboard layout but when I connected this device to phone, there is no pulse in phone reciever. Please notify me what am I doing wrong!! And here is my implementation ...
0
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1answer
251 views

Building a telephone spy

I am implementing the following circuit but I am stuck at one point. How can we input the wires in IN1 , IN2, OUT1, OUT2? I don't know which wire to insert because there are almost 4 or 5 wires ...
0
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2answers
276 views

Limit a radio to a single station

We are organizing a game for students where we are transmitting the daily objectives and hints over from an FM transmitter. Is there a way to limit basic radios to only be able to pick up a certain ...
3
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1answer
2k views

arduino rf communication: beginner

I would like to implement a home-automation system on my arduino. For this project I would like to communicate with the different devices by radio frequency. So that would be different 433 mhz ...
4
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1answer
1k views

Can someone break down how this receiver works?

I'm having difficulty understand how this receiver works due to its size. It was taken from this site: http://jap.hu/electronic/rf.html. It is on top labled toy car receiver. The toy car transmitter ...
2
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2answers
1k views

High-gain omnidirectional antennas for Wi-Fi mesh

Hopefully this is the right SE site a question of this nature. Basically what I want to do is set up a wireless transmitter using a high-gain omni/directional antenna as a test-bed mesh network ...
5
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5answers
450 views

modem free high base AM data transfer possible?

not a very experienced EE, but I was thinking about a system for high speed data transfer, and it is fairly simple conceptually, so I imagine that there must be serious flaws with the method, because ...
5
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3answers
4k views

How to build cheap radio propagation beacon?

I want to build a Radio Propagation Beacon but I would like to find an integrated circuit that does most or all of the work of the transmitter. Transmit to 28Mhz (Ham 10-meter band) Allow me to feed ...
5
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2answers
469 views

Need suggestion in choosing an effective wireless Transmitter and Receiver

My requirement is to transmit a binary form of data from one Road Junction to another road junction which is around 4 to 5 km away. I am going to get the traffic information from each road in the ...