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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2
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2answers
3k views

What RF transmitter and receiver to buy for long range

I have 3 main questions that I want to know. I mostly worked with computer science but recently I got an arduino to play around with. I also extracted some motors from an old rc quadcopter that i had. ...
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2answers
61 views

could I just add a microcontroller or timer to this transmitter circuit to turn it on and off so that it lasts longer?

I am thinking of making my own UHF tracking transmitters for a wildlife study. Could I just connect a low power microcontroller to the Vcc part of this circuit http://www.instructables.com/id/Tiny-...
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2answers
2k views

FM Transmitter Power and approx Transmission Distance Calculation [closed]

I am a beginner of electronics and mostly fascinated by hobby circuits right now. I do not have any Electronics Degree. Internet and hobby Electronics books are the only places where I learned lill-...
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1answer
126 views

Purpose of L2,L3 & C6 in the following CW transmitter circuit

I have been trying really hard to understand the purpose of L2, L3 and C6 in this CW transmitter, especially L3 and C6. I have received many conflicting answers such as that L3 is acting as a ...
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2answers
2k views

FM modulation with crystal oscillator [closed]

I have seen many posts where a simple AM transmitter can be made with a crystal oscillator and modulation transformer. Can this idea somehow be modified to FM. I don't want people to misunderstand me. ...
22
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1answer
2k views

Optical audio transmitter can't handle speech

This is a question relating to my project on an optical audio transmitter. I wired up a very simple device in which I use an audio signal transformer (EI14) to modulate the intensity of a laser beam (...
3
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2answers
775 views

Is it possible to make a coil-less simple Shortwave Receiver

I am really a newbie here in Electronics and I'm into it as a hobby/passtime. I was going through this simple coil-less Shortwave Transmitter circuit on a blog. Q1 – BC548, X1 – 10.7 MHz ceramic ...
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2answers
492 views

433MHz receiver compatibilty

Currently I have a setup where a 433MHz Transmitter sends a number from one arduino and a 433MHz receiver picks it up for another arduino. The Transmitter and receiver are of the Super Regenerative ...
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2answers
1k views

Understanding the Michigan Mighty Mite

I'm quite interested in this rather simple transmitter design called the Michigan Mighty Mite, described here: https://makerf.com/posts/mighty_simple_shortwave_transmitter I'm familiar with resonant ...
2
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1answer
4k 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 ...
0
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1answer
470 views

DIY FM Transmitter [closed]

simulate this circuit – Schematic created using CircuitLab I can not find the frequency from an FM receiver... I am not sure for the coils Henries... I tried to make on of my own and I used: 19 ...
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2answers
697 views

Walkie-talkie transceiver [closed]

I'd like to build a set of miniature two-way (half-duplex) radios that operate on the FRS band. It seems that transceivers for this band would be widely available. However I've not been able to find ...
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2answers
65 views

Phase modulation in the polar transmitter

In the polar transmitter, after the I and Q signals are converted to amplitude and phase, where the phase is in the range of -pi to pi, the phase is further differenciated to obtain the change in ...
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2answers
126 views

Datasheet FM Modulator

Hi I want to implement a narrowband FM transmitter and I find all features about power and noise in the FM Modulator datasheet, but nothing about bandwidth. The transmitter will work at center RF ...
3
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1answer
2k views

Advantages of Heterodyne vs Homodyne

What are the main advantages from a theorical point of view of a Heterodyne transmitter versus a Homodyne Transmitter? I've seen the main difference is the VCO or PLL connected to the Mixer after the ...
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2answers
2k views

315 MHz Reciever/Transmitter Raspberry Pi

I bought a receiver and transmitter (I can't find the link, but it says FS1000A and LR1 315.00 on it). I also have a set of remote controlled wall outlets that operate on 315MHz according to the FCC ...
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2answers
48 views

creating worst-case scenario test environment for wireless

I'm making a project which involves the use of two HM-TRP radio modules. At this time, the only way I can test the strength of these modules is to go out on the street and travel with one unit for ...
3
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2answers
11k 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
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2answers
34 views

Transmitter max output when checking ohms in parallel

To make my question simple and easy to understand I am giving an example below. I have an RTD (platinum 100) which change resistance with increase in temperature, for checking that rtd is showing ...
1
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1answer
104 views

Why is my RF circuit behaving like this?

I am not an RF engineer but play one at work. I am working in uhf SatCom. In the lab, In order to test two radios communicating over a satellite, I built a small RF circuit out of cots components. I ...
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0answers
52 views

Transmitter design methods using 0201 SMD

I have some experience designing an IOT transmitter (315MHz/345MHz/433MHz) using 0603 SMD parts, but am considering building a transmitter for production using 0201 parts. My question is, what is a ...
0
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1answer
38 views

Maximum tolerance for a loop trace-antenna's capacitor

While going through the document at https://www.silabs.com/documents/public/application-notes/AN639.pdf I have read from "Figure 13. Loop Antenna Simulated Mag(Zin) vs. CP1" below that even a 2% ...
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2answers
127 views

Choosing hardware for an RF application [closed]

My goal is to build a battery powered RF transmitter that will reach its accompanied receiver through trees, tall grass, brush, and some outside terrain at a reasonable distance (up to a couple miles ...
2
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0answers
125 views

Reverse Engineering a transmitter circuit

This circuit is from a radio transmitter electric gate keyfob. -> http://www.easygates.co.uk/product_info.asp?ProductID=340 I want to make my own keyfob. How would I go about finding or creating a ...
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1answer
1k views

Unstable output in VT pin of HT12D decoder

Hi everyone, I have been recently working on a RF operated water pump project. For this purpose i bought a RF RX and TX module which has HT12E and HT12D chips as encoder and decoder. The D8 (Dout) ...
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10answers
5k 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 ...
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0answers
308 views

Good compact antenna for FM audio transmitter module?

I've been looking at building a short range FM transmitter using this module, the idea is to create a small module that I can integrate into other projects. I'd prefer having the antenna on the same ...
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1answer
101 views

Does circled transistor or capacitor value cause buffer stage to stop transmitter from working?

I built myself an FM transmitter with an enable option so I can interface it with a micro controller. The Enable line is set through the micro via a 1K resistor (not shown). Once set to enable, the FM ...
2
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1answer
694 views

fm transmitter booster - can it even work?

In my research I ended up on jameco electronics site and they had an online course on FM transmitters located at http://www.jameco.com/Jameco/workshop/JamecoFavorites/fmtransmitter.html. I followed ...
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0answers
370 views

Adjusting 300Mhz FM transmitter values for max legal power/range in canada

I read a law for canada and it states: Industry Canada permits transmitters that have an output lower than 100 µV/m at 30 meters (approximately 1 microwatt output). Now what fools me are these ...
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1answer
384 views

Will a RF IC transmitter work without any antenna?

The IC is this one - https://www.silabs.com/documents/public/data-sheets/Si4012.pdf It seems i have set it up correctly according to its I2C dialog with the MCU, but nothing gets received by my SDR. ...
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1answer
165 views

Smaller ultrasonic transceiver

I am a beginner working on my Arduino-based proximity sensor array project, like this one. I have already tested the functionality with single HC-SR04 transmitter/receiver and now I would like to ...
0
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2answers
186 views

Microprocessor & sub 2.4GHZ transmitter for underwater application

I am looking for a device that has following properties: Can transmit data underwater (sub 2.5GHz,1-2m below surface) Very small (max. 15mmx15mmx2mm) In-built microprocessor Able to read sensors So ...
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4answers
1k views

practically how to estimate the exact distance between transmitter and receiver in wireless network [closed]

I want to know the estimation of exact distance between transmitter and receiver in wireless networks. Can the distance be calculated? What would I have to do to find the exact distance?
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1answer
132 views

Multiple antennas vs signle antenna

I have a radio transmitter (for my quadcopter) and I wanted to improve its range. So for now I removed its integrated antenna and I soldered a male sma connector so I can plug in any antenna I want. I ...
1
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1answer
652 views

How to design a 10GHz PCB antenna

I am a newbie in antennas generally, although I have a good grasp on electromagnetism and the physics involved around the topic. What I want to do is to build a system that will be emitting a wave ...
1
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2answers
638 views

IR Transmitter for smartphone

My understanding problem is as follows : on figure 1 for the signal 2 (noted: S2) . If I understand correctly, the LED cannot reach S2 signal because polarity. Carrier Frequency is 38 KHz let ...
6
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2answers
7k views

What is the advantage of differential Manchester

I can see the advantage of Manchester code over NRZ: you get clock and data in one signal combined. But what does differential Manchester add to that?
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2answers
320 views

Best communication option for multiple arduinos?

My father and I want to develop a cow pedometer to measure a cow's activity. The idea is that if you can measure a cow's activity you can detect when she enters heat. Detecting heat with sensors will ...
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1answer
188 views

Stability of crystal and crystal-less oscillator transmitters

I have stumbled upon this very cheap so called "crystal-less" RF transmitter: http://www.mouser.com/ds/2/368/Si4012-35123.pdf It says there on page 5 the Carrier Frequency Accuracy is 250 ppm while ...
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2answers
985 views

Can I use a DAC to tune a VCO?

I found some FM transmitter circuits with the MAX2606 VCO. Example: Can I replace R1 with the DAC output from an AVR microcontroller? Or can I connect the DAC directly to Pin 3 of the MAX2606?
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1answer
784 views

High Frequency Oscillator

I have been experimenting with the BiPolar Transistor transmitter circuits. They worked well on the 88 - 100 MHZ Range. I am now looking to increase the frequency to about 1-2 GHZ. I cant find a ...
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2answers
783 views

On/Off Transistor Switch by pulses of Voltage

So I have a remote switch to control a light bulb. The transmitter circuit basically consists of: -transmitter IC ( RF 433M Hz) -DC power supply -Switch ( turn on/off by applying voltage, ...
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1answer
82 views

Broadcasting channels per transmitter [closed]

Are television transmitters designed to broadcast two or more 6Mhz channels? Do commercial broadcasters do it in practice? If so, what are the limits (2, 3, 4... channels)?
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1answer
63 views

Which filter is good for GSM transmeter design Butterworth, Chebyshev or Bessel?

I have to select a filter design topology among Butterworth, Chebyshev or Bessel. Based on your experience, can you suggest which filter is the best for GSM transmitter design?
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1answer
2k views

Can I make a homemade radio transmitter?

I got a new HTC one m9 and it has an FM reciever in it, it picks up all the radio channels in my area really well. I am trying to make a very simple radio transmitter for the fun of it. I dot want ...
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1answer
72 views

Is it possible to induce few volts IMPULS over 10 m distance?

I'm currently learning about electromagnetism at college, so this question is on mine mind for a few weeks. If we have on one side: 9 V battery, DC-DC converter to few kilovolts, capacitor, button, ...
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2answers
868 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 ...
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2answers
284 views

Can a standard computer function as a radio receiver without additional hardware, and how? [closed]

Can a standard computer function as a radio receiver without additional hardware, and how? Thanks, and happy holidays.
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2answers
6k 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 I'...

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