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
21 views

transmitter and receiver switch

I need to build a wireless switch (preferably RF) for a LED and possibly trigger a sounded alert using a transmitter and receiver pair and it needs to have a range with a strict maximum of 2 meters. ...
0
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0answers
13 views

T/R switch for single element material thickness testing (-200V pulses)

Our non destructing ultrasonic inspection design now has two crystals, one for transmitting and one for receiving. We would like to have only one crystal for transmitting and receiving. This is common ...
0
votes
1answer
26 views

How to adjust or obtain different IR Transmitter's distances?

I would like to recreate a infrared concept used by in the vacuum cleaning robot's charging station. I would like to use 3 infrared transmitters all in same wave length and transmit a synchronized ...
0
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2answers
51 views

Understanding a simple crystal oscillator transmitter circuit

I've recently built this circuit: http://makerf.com/posts/mighty_simple_shortwave_transmitter It works on the desired frequency as you can see from this video : ...
0
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0answers
34 views

One Transmitter for multiple recievers

I need to track case pans at work, I would like to do so by using cheap 433Mhz receivers. My problem is we have up to six hundred case pans in the building at any given time. Will I be able to use one ...
0
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2answers
52 views

What technique can I use to focus a Bluetooth 4 transmission (or at least shield it)?

I'm actually trying to focus an iBeacon that uses Bluetooth 4.0 LE. These transmit in the ISM band from 2.4 to 2.485 GHz. Normally these things radiate in a spherical, or half spherical pattern, but ...
-1
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1answer
85 views

RF - separate transmitter and receiver antennas for half duplex

i was wondering why is it for just half duplex systems, don't we have a dedicated transceiver and a dedicated transmitter antenna. ok, just hear me out... assuming we are using grounded monopoles, ...
1
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0answers
51 views

Best transmitter and receiver for the job? [closed]

I am very much an amateur when it comes to this just to warn you. I am trying to build a device which will on the press of a button has a transmitter send a 6 digit code to a receiver, which will ...
0
votes
3answers
151 views

How to build a simple LED transmitter and receiver

I'd like the distance to be about 1/10th of a mile; less distance will be fine if that's easier to build. What tools and parts may I need for this? I have plenty of LEDs lying around and I have ...
0
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0answers
25 views

High level sensor protocols

We are developing a sensor gateway for industrial usage (a kind of internet of things transmitter). The type of sensors are slow frequency sensors with measurement intervals above 1 second (e.g. for ...
1
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2answers
47 views

What are the trade-offs of transmission bands?

If I were designing an RF circuit how do I determine what band the circuit should operate on? What are the trade offs? and why is the higher the frequency the lower range? It is quite un-intuitive for ...
0
votes
1answer
70 views

Questions about FM receivers and transmitters?

I have a test tommorrow on phase lock loops, AM/FM receivers along with several other topics. I need to understand this topic clearly before I take the exam to advance to the next schooling in the ...
10
votes
2answers
556 views

How does the plastic-tube inductor in this wireless transmitter work?

This single layer PCB (solder side shown here) is from an old fan remote: The inductor in the plastic tube is not connected physically to any components; however, the two loops of wire surrounding ...
0
votes
2answers
53 views

Peak-to-peak voltage of WRL-10534?

I'm experimenting with the 434 MHz RF Link transmitter (WRL-10534) from SparkFun. I'd like to determine the peak-to-peak voltage of the RF output, but I don't have access to an oscilloscope that can ...
1
vote
1answer
58 views

Wireless transmission power for multiple receivers

I have just started learning about wireless systems and for some reason I'm hung up on what I feel is a fundamental idea. Consider some transmitter-receiver pair with isotropic antennas. The receiver ...
0
votes
1answer
38 views

Replace LED by a Trasmitter

I need a wireless switch with capability to report current state, so I would like to modify a wireless switche like this, by replacing a current state LED by a trasmitter to get the state of current ...
1
vote
2answers
142 views

square wave carrier signal

I am having some trouble to put things together into one picture. Can a modulated carrier wave be a square wave? If yes then How? Because at resonant frequency at the transmitter, the current ...
1
vote
2answers
128 views

How would I measure distance with a transmitter/receiver pair?

I am looking to build a a device that can transmit/receive its distance from another device, with the other device doing the same up to 50 meters. Will using a fm transmitter and receiver with a ...
9
votes
4answers
456 views

How is it possible to have a 5W transmitter driving 50 ohms with a 12V supply?

So let's say you have a circuit, which generates a carrier wave at some frequency (let's say 27MHz) and it's connected to a 50 ohm dummy load (which I gather is equivalent to an antenna for circuit ...
1
vote
2answers
54 views

Distinguish between two ultrasonic transmitters

I want to have two ultrasonic transmitters emit signals to three receivers for measuring distances and relative position of the transmitters to the receivers. The distance between the transmitters is ...
0
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1answer
65 views

Orientation of ultrasonic receiver

I would like to use an ultrasonic transmitter and three receivers to be able to determine the position of the transmitter relative to the receivers. The distances to be measured are around 3-4 ft. I ...
-1
votes
1answer
304 views

What is the best and simple circuit diagram for a radio receiver to receive radio waves in Citizen's Band [closed]

I am building a two way radio system using the citizen's band in India. The transmitter is using a 555 timer IC clocked at a frequency between 26.957-27.383MHz to transmit AM waves. Can you please ...
0
votes
3answers
179 views

What's the relationship between samples and bits?

I was talking to a friend today that I have a transmitter which is capable of sending 128 samples/second. Note that each sample is a voltage level represented by a floating point decimal. He then ...
0
votes
0answers
202 views

Datasheet for Keyes IR Transmitter (KY-005) wanted

Can someone help me find the datasheet for the Keyes IR Transmitter (KY-005)? I know how the pins work, I just need to figure out its voltage drop and how much current should go through it. Thanks! ...
0
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0answers
39 views

Is this an antenna or an inductor or both? And does the wire length/core diameter matter?

I have a small transmitter, and attached to it is this device: However, one of the wires attaching the circuit board to to circular red device is broken. I figured that since I have it all taken ...
0
votes
1answer
225 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
45 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
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3answers
122 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 ...
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votes
1answer
42 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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votes
1answer
60 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
292 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
119 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
104 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
109 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
349 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
89 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
678 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
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0answers
188 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
107 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
133 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
175 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
104 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
408 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
183 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 ...
9
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
629 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
3answers
76 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
136 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 ...
0
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1answer
131 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
471 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 ...