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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1answer
20 views

Calculating link budget

I was reading and found that there are different ways to calculate "link budget" and I want to know which one is correct because they are confusing to me. For example, some sources state ...
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2answers
61 views

Sending serial data over analog TV coaxial cable (RF-band)

TL;DR: I would like to transfer digital serial data over an existing analog TV cable. How do I do that?   Full Question: In order to transfer some data to a device's control lines remotely, I'm ...
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1answer
53 views

DIY colpitts oscillator not oscillating

I am trying to make a FM transmitter. For the oscillator part I picked a colpitts oscillator as it seemed relatively simple and I could get the pretty high frequency needed for FM with it. I built the ...
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0answers
40 views

AC servo position flight surface control system [duplicate]

So if a control transmitter is used to set the Pilot's input command signal and a control transformer is used to compare this desired position to the current position and produce an error signal. My ...
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4answers
4k views

Why are color difference signals transmitted rather than R,G,B signals?

In color television systems back in the early days, people used to transmit color difference signals (Y-R) and (Y-B) along with Y, which is the luminance signal. My question is why are color ...
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0answers
21 views

Multiple CC1101 receivers and senders

I would like to implement multiple receivers/senders with CC1101[1] from TI. Idea is that all receivers are listening for specific commands and do their job, after that if some specific receiver reads ...
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29 views

Which 433MHz transmitter module can be used for battery operated wireless communication having vey low current consumption (less than 5mA)

Im designing a wireless water level controller. The WLC detects water between overhead and underground tank. The transmitter will be situated at each of the tanks. After water level sensing , the ...
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2answers
61 views

Calculating capacitor capacitance between collector and emitter in radio circuits

In many radio transmitters and receivers there is a capacitor between emitter and collector. As shown in this answer this capacitor gives positive feedback to prevent decay. My question is that, how ...
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69 views

Short range FM transmitter

I made this FM transmitter from this video (https://youtu.be/joFourugXvs) but it has a very short range (30 cm). Where's my mistake?
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1answer
43 views

How to make the HT12E transmit (TE to low) only when one or both buttons are pressed?

I followed this video: https://www.youtube.com/watch?v=-xK0B_bM-yk and made these circuits: Transmitter: Receiver: And they work as I want them to. I have 2 pushbuttons so when one or both of them ...
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1answer
44 views

pulse transmitter operation

I'm trying to get a better understanding of how this 1.5v pulsing transmitter works. I found it on Youtube and modeled it up with some success. https://www.youtube.com/watch?v=aLS9DsF2ilg The ...
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1answer
68 views

FM modulation, amplitude problem

I'm trying to make an FM modulation with a Hartley oscillator that oscillates at 45MHz. The problem is that it's supposed to have an unitary gain. I can't find a good adjustment between a really low ...
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4answers
70 views

FM Transmitter oscillation problem

I've been trying to get this simple FM transmitter to work over the past few days and I could use some help in a few areas. First iteration was on a breadboard with all parts included. The ...
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1answer
24 views

RF modules flickering

I have an rf transmitter and receive set up on a basic circuit so that when I connective data pin of the transmitter to the 5v, the receiver should detect it and the LED turns off. This mostly works ...
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3answers
165 views

Schematics RF transmitter

I'm attaching a schematic of an RF transmitter made by Synoxo. Chip is the SYN115. The schematic is found in the datasheet. I do not understand why L3 which is the PCB antenna (pointed with the red ...
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2answers
150 views

How to transmit a 125kHz signal?

I want to transmit a 125 kHz signal. The square wave signal is generated by the microcontroller (just transmitting no data and no receiving,) the transmitting and receiving antennas are tuned to ...
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24 views

What code rate is required for cellular transmission?

I've been doing some reading about various error correcting codes in wireless communications such as Hamming and LDPC. Since there is a trade-off between code rate and robustness, I am curious how ...
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2answers
107 views

AM modulation stage for small transmitter

I am trying to build an AM radio transmitter. I have built a Colpitts oscillator with a 7 Vpp output and an audio stage with a 1 Vpp output. I am trying to build the amplitude modulation stage I am ...
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1answer
36 views

Maximum transmit power allowed for 802.11g

I'm learning about the 802.11 regs. In a book I'm using, "CCNA Wireless 200-355 Official Cert Guide (Certification Guide) 1st Edition by, David Hucaby (Author). Page 53", it has the following clause ...
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2answers
39 views

Fast Ethernet transmitter structure

Does anyone knows internal structure of a typical Fast Ethernet 100BASE-TX transmitter? I wonder how MLT-3 voltage levels are formed and what can cause abnormal voltage levels at the PHY output? ...
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3answers
74 views

In Amplitude Modulation transmission, why do we need to mix (multiply) rather than just add the carrier and base-band?

Why is it necessary to mix the carrier with the message signal to create the sum and difference of the frequencies when you can just add both signal? Not only is it much easier to achieve but it would ...
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1answer
145 views

Making a Remote Control for My TV from Scratch

This might seem silly to many of you, but I lost my TV remote when I moved awhile back and instead of buying a universal remote for cheap, I want to make a remote for my TV from scratch myself. I'm ...
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2answers
98 views

Relationship between radio transmitter output power and its input electrical power?

Given a radio station of a given licensed effective radiated power, is it the case that the transmitter requires at least that much mains power to run it? E.g., if a radio station says it's 100,000 ...
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10answers
3k views

Best practice in transmitting sensor analog signal over longer distances (approx. 100') — in cost sensitive products for microcontrollers

I'm looking for best practices for transmitting an analog sensor signal over long distances to a microcontroller such as the Arduino running at 3.3v or 5v. Keeping costs low is imperative. SPI and ...
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3answers
267 views

Best way to amplify 3.3V square wave at 1MHz to 10V square wave at 1MHz

I am trying to build a bus transmitter complying to 1553 standards. Its input is a 3.3V square wave at 1MHz (CMOS data) and it has to be amplified to 10V or higher at the same frequency. The load ...
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6answers
2k views

How to end sending data over I2C by Slave or Master?

Let us say a Slave or Master is sending multiple bytes to the receiver on I2C bus and the number of bytes is not defined before hand. So then how will the sender tell the receiver that it has no more ...
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0answers
53 views

RFID spoofer with extended range

I have recently found this tutorial online about making a simple RFID spoofer, using only Arduino, used paper roll, coil wire and some passive components. I thought it was pretty neat and decided to ...
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1answer
42 views

ensuring transducer (transmitter) and receiver polarity

I am trying to implement a simple phased array of 7 transmitters rated 40 kHz. I have a few receivers to measure the acoustic field generated to validate if it works. What is a simple way to measure ...
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0answers
83 views

How can we actually use PPM output from a RC receiver

I'm using FS-CT6B transmitter with R6B receiver. I have seen many code examples and tutorials for reading PPM output from R6B using Arduino Uno. In some of them, only one pin is used (external ...
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1answer
70 views

Can long-range radio waves from an RTV tower penetrate thin plastic composite material next to its source?

We are currently developing a conceptual design for the renovation of Croatia's main RTV tower located on 1033 meter tall peak Sljeme at the Medvednica mountain north of Zagreb. The idea is to ...
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3answers
380 views

Strange-looking FM transmitter circuit

I found this simple FM transmitter circuit: I built it an it works rather nicely. There are many simple FM transmitter circuits on Google, most of which look basically like this: These work by ...
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1answer
184 views

Collector-Base capacitance in simple FM transmitter

Here is a schematic of a simple FM transmitter. I understand that this work in the following way: the sound picked up by the mic is translated into a voltage at the base of the Q1 transistor. As the ...
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1answer
430 views

Tube Transmitter Issues

I'm back working on my friend's 807 tube transmitter. I've had some previous posts on this and I'd like to thank all the people who responded for your help! I bought an oscilloscope and a dummy load ...
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1answer
157 views

How to transmit complex numbers from USRP B210 using two antennas simultaneously? [closed]

I am using one USRP B210 board with two transmission antennas as my transmitter and another USRP B210 with single antenna as my receiver. My goal is to transmit a file such that I am using both the ...
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1answer
68 views

How to transmit a signal to a point [closed]

I have a signal generator (Digital Dual Channel Funktion Signal Generator) and want to generate two signals (530 and 550 Khz signal) and want to transmit these generated signals to the points on a ...
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2answers
149 views

Is a coil FM transmitter frequency affected by my body static?

I've built this coil FM transmitter following these guides which are essentially the same: https://maker.pro/custom/tutorial/how-to-make-an-fm-transmitter https://www.instructables.com/id/The-...
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1answer
56 views

Transmission of serial data characters

On a serial data link characters are transmitted data rate of 9600 baud. if characters are 8 bits and there is one start bit and one stop bit per character, then what is the number of characters ...
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1answer
78 views

How frequency is modulated in FM transmitter circuit [duplicate]

I am new to looking at FM transmitter and have a few questions regarding the FM Transmitter circuit below. Please break down your answers as simple as possible as I am not as well versed in circuits ...
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1answer
163 views

Trouble using a generic 4-20mA to 0-5V board to connect transmitter to Arduino

I'm doing a big project, where I will connect a lot of sensors to my Arduino Mega 2560. Eagerly, I bought boards of this type, but I can't get them to give me any voltage output! I've connected them ...
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1answer
42 views

Rf Module Receiver With Pt2272 always gets signal

I am just trying to on and of an led with rf module. I have tried lots of module but my works end up with same result. When I feed my receiver, with led connected to data out, it always powers the ...
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0answers
235 views

Low latency wireless audio transmitter

I am working on a project that requires low latency wireless point to point audio transmission at short distance using a digital transmission technique (ideally 24bit 96khz audio, 30 metre max) at a ...
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1answer
132 views

How to increase frequency of my rc device? [closed]

I'm presently trying to increase the distance i can use a rc device. So I want to know how I can do it?
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1answer
38 views

DC Free Transmission SNR

My SNR is better with DC Free transmission. Why? Example: 1.) Datasignal with DC: Datastream consisting of 0V and 1V. 2.) Datasignal without DC: Datastream consisting of -0.5V and 0.5V. The ...
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1answer
132 views

can I use a choke 150uH inductor for my AM transmitter circuit?

I am trying to develop an AM transmitter but I am having problems with getting a variable capacitor and inductor (for the rf circuit) in my location. I was able to find a choke coil with an inductance ...
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0answers
56 views

Microphonic SAW transmitter?

I built this very simple SAW transmitter, with a simple "spring" antenna for the right frequency. To test it, I tuned a portable receiver to around 433.92Mhz and fine tuned it until I heard silence. ...
6
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2answers
852 views

Tube transmitter tuning

I am trying to tune/tweak/repair this transmitter for a friend of mine. It is oscillating, and it has rf power on the antenna, but it just doesn't seem as "strong" as it should be. The diagram says ...
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1answer
93 views

Tube transmitter plate current meter question

Can I install the mA meter in this schematic directly in the circuit? This is the high voltage plate supply and there is RF on it. The diagram doesn't specify if there is any circuitry to adapt the ...
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3answers
84 views

Wire size question

I am trying to figure out AWG from a European/German schematic. The wire is listed as 0,3mm. (That's 0 (comma) 3mm.) I can find wire for sale in this diameter, but I need a reference to AWG. Is ...
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1answer
108 views

Can I connect transmitter output to spectrum analyser input directly?

I have a spectrum analyser, that tolerates 30 dBm 50VDC signal on its input and has internal selectable attenuator up to 40 dB. Can I connect it directly (i. e. without any external attenuators) to ...
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2answers
318 views

3.5 MHz 2W AM vaccum tube transmitter [closed]

What do you think of my 80m band radio transmitter I designed? Originally I though about using an Armstrong oscillator, due to its simplicity and sine wavyness, but I heard that crystals are better, ...

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