Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [radio]

Radio is the technology of signaling and communicating using radio waves.

Consider using the rf (radio frequency) tag.

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Why don't interfering radio stations both play at the same time?

Since radio-waves are additive, I would expect that overlapping stations (eg. two different signals broadcasting on 95.7 within range) to both play over my radio at the same time. But that's not what happens. Instead, I hear only one station at a…
BlueRaja - Danny Pflughoeft
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Do radio receivers use any power from a transmitter?

Someone gave me this analogy - turning on your TV or radio does not cost the broadcaster more money because the radio waves would otherwise be dissipated by the air or other objects. Is this correct? I find it difficult to believe - surely some…
Thomas O
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Is this Radio Frequency and will it work?

I really don't understand radio-frequency and how it works, and I get very confused on the theory and how an antenna etc. works. I first start with the electrical transformer. Energy is transferred through the magnetic field transferring the AC…
skyler
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What does the term "fixed" mean on the radio spectrum?

On the United States Radio frequency allocation chart, the term "fixed" radio comes up a lot. What does that mean? Who is allowed to used "fixed"?
skyler
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How does pseudo-random noise increase DCF77 accuracy

A few years ago the Germans added a pseudo-random noise signal (from a LFSR) to their time reference DCF77. I heard this should allow you to get a more accurate signal at the receiver side. But the signal delay due to the distance (up to 2000 km)…
radagast
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Radio Frequency Penetration

I've learned recently that lower frequency radio waves travel farther and have better object penetration than their higher frequency counterparts. With this in mind, I was pondering about the two-way radios we use on the ship I work on. Most…
Duff
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Low parts count and cheap radio modulation (hack)

I have an embedded electronics project in mind, but will use a different example to explain what I wonder. Say we have to PCs, each with a sound card which can sample up to 44kHz. How do I get those to talk to each other over radio? It helps if the…
Prof. Falken
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relationship between frequency and signal strength

I know that [the commercial broadcast] radio spectrum is divided into several chunks and each chunk is assigned to be used by different radio stations. Suppose that radio station S1 is using 93MHz and radio station S2 is using 94MHz. My question is,…
user2198419
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What advantages to permeability tuning as against capacitive tuning?

I learnt recently about the RBZ80 ; a vintage valve receiver which used variable permeability tuning rather than variable capacitor tuning. In thinking about the possible reasons for permeability tuning in lieu of capacitive tuning the thoughts…
Everyone
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Why do my 433 MHz receiver and transmitter modules not work reliably?

Background To learn about radio, I started with the simplest module I could find: a simple 433 MHz receiver and transmitter module pair, where you can use RadioHead ASK to bit-bang a signal on the MCU. I purchased the most widely available module…
Nick Bolton
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How can I mitigate risk of electric shock?

I want to start a new project and build a PC in an antique style radio. The back of it says "CAUTION RISK OF ELECTRIC SHOCK. DO NOT OPEN" It's just a 120V 60Hz 8 watt radio, but this warning has me wondering how to discharge the thing safely. What…
flashnode
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Full duplex shared frequency radio?

Normally shared frequency analogue1 radios (CB, aviation, etc.) can't receive when transmitting, because the signal being transmitted is much louder and will jam any signal from different transmitter. Is it possible to somehow subtract the…
Jan Hudec
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Radio Transceiver bulkhead connection and Ground

I have a problem regarding mounting of RF transceiver. The main board inside metal cabinet is floating and when I check the antenna SMA bulk connector its outer case has a connection to circuit ground. This would eventually short the chassis ground…
Adi
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What modulation does Short wave broadcast stations use?

I have small Short wave receiver for the 7 broadcast bands. (49,41,31,22,19 and 16 meters) What Modulation do they use in this? The radio is a small grundig mini 300 world band reciever.
skyler
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Crystal Radio Circuits

What are the differences between these two crystal radio circuits? Circuit #1 Circuit #2
vu2nan
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