Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [receiver]

Use this tag for questions about the theory and structure of receivers.

A radio receiver is an electronic device that receives radio waves and converts the information carried by them to a usable form, usually in the form of sounds, images or data.

The technology of detecting RF energy has progressed since it was first demonstrated at the end of the 19th Century. Moving from early crystal detectors through vacuum tubes (thermistors) to solid state transistors.

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How can I avoid accidentally transmitting with a Baofeng UV-5R?

I don't have $500 for a radio scanner. If I know the few (analog) frequencies that I would like to listen to, I think one can use the Baofeng UV5R (which doesn't cost much). The only problem is that one accidentally can transmit with this and this…
user4777
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Is there a way to listen to live HF communications using the internet?

I'd like to be able to show people what a QSO sounds like without having my transceiver available. Is there a way I can listen to amateurs talking in real-time (or using Morse code) on the HF bands using my internet connection and the speakers on my…
dcaswell
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How would a time-difference-of-arrival receiver with two antennas know which side the signal is from?

An easy TDOA design by Byonics was published with the following schematic: It appears that the antennas are switched at a rate of 640Hz, which allows a 640Hz tone to be heard in the radio when the antennas are not in phase. When the antennas are…
Adam Davis
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How To Join Packet Radio BBS

I'm a complete newbie here, and on the Southeast Coast of the USA. I don't even own a ham radio yet. Some preppers and I got to talking about a dystopian time of Internet collapse where shortwave radio might be an important factor of survival. This…
Radio1
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What is a "roofing filter"?

What are roofing filters? Are there different kinds of things that are called roofing filter? Why would a circuit or component be called a roofing filter instead of just a IF bandpass filter? Why is the word “roofing” used? (as it seems to have…
hotpaw2
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Share antenna between receiver and transceiver?

I recently put up a fan dipole for 80/40/20/10. I'm looking for a way to share this antenna with a receive-only SDR and my shack transceiver. Obviously I can just switch this antenna between the two manually, but I was hoping there was a way to have…
s3c
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Why would you need a signal generator to receive early satellite transmissions?

I recently watched, on You Tube, a NOVA program about the British school masters and students who were the first to publish the news that the Soviets had started launching satellites from a new launch site back in 1958. (School Boys Who Cracked the…
John Warren
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What is meant by "poles" when discussing filters?

I was looking over the product page for the K3 (dreaming I know) and noticed that they offer a variety of crystal filters. Some are 5-pole and some are 8-pole, other than price, what is the difference and what is meant by "pole" in this context?
WPrecht
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If someone transmits on 151.88 MHz and I listen on 151.18 MHz, how likely would I hear their transmission?

I have a cheap baofeng uv-5r, and I sometimes hear an intermittent transmission which pulses past the squelch threshold with periods of dead space between, roughly 0.75 seconds or less. My job uses a repeater and radioreference.com lists the used…
Wolfgang Steele
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Connect two receiving antennas to the same radio

I have built a 1090 MHz ADS-B antenna roughly following some video instructions. It appears to work reasonably. However, because of how it is placed, it captures signals for more or less a half of the sky. So I would like to build another and put it…
Giovanni Mascellani
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Would it be possible for a software-defined FM receiver to demodulate two signals on the same frequency?

When two FM signals are transmitted on the same (or about the same) center frequency, either you hear only one or you hear that noise I'm sure most of you have heard. Would it be possible for a software-defined receiver to track both signals and…
Someone
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Are there ways for people with receivers to participate in contests?

At the moment I only have an HF receiver (or I will when I build it, hopefully soon). Are there any contests I can participate in, or ways for me to participate in a contest without borrowing a transmitter or working with an amateur who has one?
Adam Davis
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How Could Superheterodyne Receiver Ever Work?

I am surprised how the Superheterodyne Receiver still works and is still in use after coming to realise the impact of Image Frequencies on its performance. Basically, I'm curious how engineers make such an architecture work despite the affect made…
Denis
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IQ imbalance after quadrature mixing

What is IQ imbalance in the output of complex or quadrature downconverter/demodulator/mixer? What are the causes and effects of IQ imbalance? (A spike in the spectrum display of RF noise?) Are there any SDR algorithms for reducing the negative…
hotpaw2
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Why do I only hear broadcasts from 150 kHz to 29.999 MHz?

I am currently studying for my amateur radio license. Until I'm licensed, I'm trying to use a Sony ICF-SW7600GR receiver to listen in on amateur radio "phone" transmissions. No matter what I do, however, I can't seem to locate any amateur radio…
rcampbell
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