What is the difference between a variable capacitor in a AM receiver and a variable capacitor in a FM receiver? I understand that Am is amplitude modulation and that the signal is carried over a changing amplitude and that the frequency is constant. And the opposite in FM signals. And a variable...
Homework Statement:: I would like to write a science fiction story on how alien quantum communication could work and how scientist on Earth build the first "radio" receiver, entangling Quantums over big distances randomly.
Relevant Equations...
Hi all
I want to develop a miniature system using GPS receiver, a micro-controller, an RF transmitter and its receiver. The idea is to acquire lat/long of buoy dropped in sea which is equipped with miniature GPS receiver (with associated circuitry) which can send its position (lat/long data) to...
I would like to discuss in detail an interesting aspect dealing with general considerations and methods to calculate the Q factor of oscillating systems on the example of this regenerative receiver.
Althought it is closely related to the discussion here discussion here (especially Baluncore's...
Which role plays an additional capacity in a receiver circuit between the antenna and the matching-box part like in this example (found in https://www.frostburg.edu/personal/latta/ee/twinplex/schematic/twinplexschematic.html):
Is it necessary for this receiver circuit or just optional? What...
For a project that I'm making it has a raspberry pi 0w as its cpu for running autonomously, But I want to make use the raspberry pi 0w as the receiver as well. The range needed is about 3000 feet minimum. Currently I have been looking at some rc and drone receivers that would work as well, but I...
So I discover that a human body can affect a radio receiver. When I get close to a receiver, the radio produces buzz sound, which means that the radio signal is disturbed. However when I touch the plastic case of the receiver, the receive becomes normal.
This phenomenon does not happen every...
I am trying my hands on building receivers and transmitters. For now I would like to build this receiver here:
now I see that the 500pH inductor in parallel witht he 200uH capacitor are in charge of filtering the unwanted frequencies. The top-left NPN is in my guess an emitter follower to...
Hi,
Here is the figure 2 that the question referred to:
How do I go about a question like this? I have made an attempt, but am not very confident with the method. Note, I have learned about/am aware of Fourier transforms.
My attempt:
So first I thought that the square wave will be at the...
i have ts832 transmitter and a rs832 receiver. i tried to build a radio receiver to pick up radio signals from the ts832 transmitter,. i measured the ts832's antenna. it was 8.8 centimeters. so i cut a piece of copper wire 8.8 centimeters long. i connected the bottom of the copper wire to two...
Hi friends,
I am studying this circuit which is the first all electronic television receiver created by Dr. Farnsworth back in 1927. Triode are being employed along with some caps and coils. The design is very simple and clear, basically this receiver is a detector circuit which detects the...
Hello, I am trying to transmit radio signals across a distance of just under 1km to the receiver. The receiver is in line of sight with the transmitter. I just need to send the data in the most direct way possible, almost like shining a laser through the air. I was wondering what type of antenna...
Hello,
I am a Biologist currently working on a Biocommunication related project.
To explain the project, I am going to use a Piezo sensor attached to the bone and it can detect bone cracks using EMI. I would first energize Piezo sensor with certain frquencies and it generates Ultrasonic waves...
What are the methods to record and Playback Radio programs tuned to FM frequencies ?
Is there a way to interface the radio receiver with DVD player or Flash drive or any other media for recording and Playback ?
Thanks & Regards,
Prashant S Akerkar
Hello.
My question is about a specific case. Assume emitted signal ihas not been created using IQ modulation, what is the interest to rebuild an IQ signal in receiver before port-processing ?
Hi,
I was wondering if any of you fine people can help me understand a few things about Howard Armstrong and Harry Houke's superhet radio receiver built in 1924. My fist question is that they used a second harmonic and I don't understand why. Where was the second harmonic used and how did it...
Homework Statement
A radio transmitter is located 17.5 km away. The broadcast signals travel at the speed of light (c = 3.00 x 108 m.s-1) through the air towards a radio receiver.
Calculate the time it takes the radio signal to travel from the transmitter to the receiver.
Homework Equations...
I'm currently working on a novel RF and MW sensor and I wanted to know whether there is a paper that shows the current very best receiver sensitivity for a range of wavelengths in the RF-MW range in dBm preferably so I can directly compare to my device.
Hello,
I have assembled the following AM radio reciever circuit:
Purpose of the circuit: To receive AM radio signals and provide the output audio of these signals ( demodulated ).
Circuit elements: L ~ 1.5mH , C ~ 300pF , Amplifier IC: LM324N , Diode: 1N4004 ...
Homework Statement
A football receiver running straight downfield at 5.5m/s is 10m in front of the quarterback when a pass is thrown downfield at 25 degrees above the horizon. If the receiver never changes speed and the ball is caught at the same height from which it was thrown find initial...
I'm completely new to transmitting/receiving signals, but I wanted to get a scope of what kind of components are out there that I could use to build this system.
I wanted to read the voltage drop across a resistance thermometer (Vt) and send this signal wirelessly to another circuit, where I...
Hello,
I am interested in making a homemade radio receiver out of common materials.
Do you have any suggestions or websites I could get some ideas from?
Thanks.
I.
Hello~
Is there anyone good to make a simple acoustic receiver,just like using an IC to connect several capacitors?
Someone pose a picture just as follow.And said that is to make a small amplifier with a single chip and the making of mono loudspeaker and double channel loudspeaker are in this...
I am looking for what the high end radar receivers can achieve in terms of sensitivity? I have had trouble finding examples online, I have seen -100 to -103dBm as typical sensitivities, but I'm looking for the cutting edge stuff. I've also seen the GPS satellites also have a sensitivity of...
Hey, I was wondering if any of you smart people could help explain in a very simple way (if possible) how the first FM transmitter and receiver worked?
I know, for example, that many current transmitters use a voltage variable conductor to change the frequency of the wave. Did Armstrong do...
I am measuring a communications bus with an oscilloscope at various points along the line. I understand that there will be reflections at each stub as well as at the ends of the bus if the impedance doesn't match. I also understand that these reflected signals will add/subtract with the...
Homework Statement
In the picture below, is a circuit of constant direct current. The receiver is made of a changable resistor with resistance R. If the reciever delivers maximum electrical power its resistance is
a)9 b)6 c)3 d)1.5 e)0.5
Homework Equations
Im having trouble finding the equation...
Homework Statement
Given symmetric three phase system (see attachment) of phase voltages with angular frequency \omega=100 rad/s, R=5\omega L=100\Omega. Find capacitance of capacitor C such that power factor of three phase receiver has maximum value.
Homework Equations
Power factor is given by...
This is a continuation of the archived thread from https://www.physicsforums.com/threads/how-to-make-inductor-coils.570700/. Judging by the list of needed coils, I suspect the author was looking to build VHR AM Aircraft Receiver as described here...
The diagram is a reproduction from instructions to perform an effective sensitivity test for a generic radio receiver. In our organization it's considered the proper way to do an effective sensitivity test for a receiver. My question is, what does the 6 db attenuator do in this case. It is...
How does a microwave receiver works? I can connect it to a multimeter and when a transmitter beam microwave to it, I received voltage and current output. When I put them closer, the output increase. How did the receiver convert intensity of the microwave to voltage and current? I assume the...
Hello :)
So my question are:
-how to build a transmitter and a receiver?
-how do they actually work?(in detail,microscopic and macroscopic)
-which scientist was the one who invented this tech and if possible,are there any papers published that can be red today?
Thank you for your time.
Hello,
I'm currently working on satellite model for high-school compatition, and I'm not sure if there's a visual difference between a reciver & transmiter antenas (on satellites)...
Also, is it possible to satellite to recive a radio wave information from another satellite
Thank you
Hi,
I'm just curious because I know wifi uses digital FFT to send and receive signals. (I can't really remember why)
But when I imagine a signal being sent its like a squiggily wave, so what method does the reciever use to approximate the instantanious values of the signal into a mathematical...
if one want to reduce pressure from high pressure receiver to low pressure receiver for example in the range of (0 to 10 bar) what he must to do?
any valve can use it for this task?
1. Homework Statement
A quarterback throws a football to a stationary receiver 31.5m away from him. If the football is thrown at an initial angle of 40° to the ground, at what initial speed must the quarterback throw the ball for it to reach the receiver? What's the balls highest point during...
Hi I was wondering if someone could tell me what kind of gases I could expect to see using an IR receiver between the wavelengths of 110 and 330 nm. As well as this id love to know what kind of glass could be used in order to not interfere with the actual results.
Thanks a million
I am curious to know how the RF front end of a Wifi receiver works. From my understanding, most RF receivers have to use networks of various oscillators, mixers, and filters to select a given frequency and remain insensitive to undesired signals at different frequencies, and I suspect that WiFi...
My 18 year-old students have just learned that an LC circuit can be used as an oscillator or as an tuner, so I would like them to build either an FM transmitter or an AM receiver as a homework. However, the only trimmer capacitors I have right now are 3-40 pF. They could build their own coil...
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 want to understand how the receivers orientation relative to the transmitter can affect the...
Hey all. So I am now trying to work on IF amps for a superhet AM receiver (medium wave) and found the following figure in the ARRL handbook:
I have a couple of questions regarding these schematics.
First and most importantly, do these work for IF signals (of 455KHz with BW of 18KHz)...
My electrical engineering teacher had us do a research project, and i decided to do my on the effects of polarized electric fields and antennas. I was reading that RHCP signals have no effect on LHCP antenna receivers. When i sent my paper to my teacher, he told me that i had to prove this...
Hello,
For convenience, we can say that a submarine at some depth in sea emits sound wave which refracts from the surface of the sea and is caught by a helicopter at some height above the sea. If we know the speeds of the submarine and the helicopter and the frequency of the emitted wave...
The GPS satellite has an atomic clock which sychronizes with the receiver. But when the receiver gets the time, it is delayed as it travelled. So when its 08h 00min 05s in the satellite, the receiver gets maybe 08h 00min 03s. The time of travel of the signal is 2s but how will the receiver...
Hi all, I am new to this forum and In desperate need of help! I'm currently at university studying product design and part of my design idea has electrical components, unfortunately I am very limited to what I understand electronically so I'm a little stuck. Basically I need to connect two key...
Dear colleagues.
please help in solving the actual problem:
Our company operates in the field of space communications .
For reception and transmission of signals via satellite is used parabolic antenna with a diameter of 12 m
Frequency of received signal is 4000 MHz.
The receiver is a Low...
halo everyone!
I am curious how to use Kinect as a motion sensor's receiver?
how to approach it?
I did try to research about it but I can't found any information about it.
Thanks
Hi All,
This seems to be the place to ask for help on a fun project I am playing with. I am wanting to make something like laser tag but with radio. I am no expert on radio so excuse my ignorance. Everyone would where a vest with a simple radio transmitter and when you pull the trigger it will...
Hello fellow science enthusiasts.
The other day I was thinking of a device for instantaneous transfer of data. You would have two entangled particles (or any even number but two just for simplicity), then you would "put" each one in two devices. An input is needed. For example a simple message...