Radio Definition and 671 Threads

I'm not sure if this is a correct forum for this topic, but I'm wondering if there is any research done on VLF (very low frequency) radio astronomy. Obviously, such telescope would have to be in space, because all signals up to 15 MHz are reflected by the atmosphere. If this was done or not...

www.pandora.com If you like music at all, this site is brilliant. What you do is enter in artists or songs you like into this website, and it will compile a radio station for you that will randomly play songs by the artists you've entered or simmilar to them. It's so awesome, I'm in love. I...

hi does somebody knows why we hear a noise when tuning a radio? I mean when you turn the radio tuner to find a station. not for a typical station. during turning the knib. I know it's becouse of a electromagnetic wave. but I don't know that wave and its source. tnx.

the question a mummy contain 9.2 g of carbon and it has an activity of 1.6 Bq. how old is the specimen in years? i worked out the question and got an answer of 2300 yrs, the closest answer in the book is 2200yrs. is my answer of 2300 yrs correct?

My understanding of EM wave emission on a particle level is that when an electron jumps to a lower energy level it emits a photon. The probability of where you will find this photon is described by a wave, so when you have a lot of photons you are safe to treat light as a wave (in most...

hi, i am looking or a lab to measure the radioactive half-life of particles. i have looked through the internet but can't find anything i like. i have access to my college's physics/chemistry labretories and have equipment. so i just need procedures for a lab. can you Please suggest a link...

Have you all seen the portable Siruis Sattellite Radio reciever with a hard drive: XM also has one of these coming out soon: I think that having a portable mp3 and satellite radio in one device is an AWESOME idea. However, these devicese can only pick up the satellite signal when docked...

A few months ago i was at work listening to the radio, which is on a desk about 3 meters away from me. Suddenly it stopped and i heard white noise. I thought the antenna had moved to i walked towards the radio. When i got near it, it suddenly started playing music again. But the nearer i got...

How is the principle of the operation of radio telescope? I am interesting that how can radio telescope translate signals to image. Does any experts can tell me?

Home Depot/ Radio Shack speed of light? [FONT=Arial]Is there a way to measure the speed of light, to say 2 significant figures, using things purchased from Radio Shack and Home Depot? I've got a 200' hallway and front surface mirrors. Thanks, Bradshaw

What is the basic concept behind radio communication? How does one vary range in it ?

can anyone explain to me why radio reception/tv reception ect.. come in more clearly when i hold the antenna? i am assuming my body is acting as a better receiver but can someone actually explain why? thank you shawn small

Is it true that it can eavesdrop the entire galaxy?, like it has the ability to scan the whole galaxy?

RADAR - Radio Detection and Ranging . Can we use the same technique on a smaller scale :rolleyes: ? I mean to measure the relative velocity between two vehicles :smile: ? Are there any good sources on internet where I can get information in detail about the working of RADAR system...

Rather curious to know whether anyone here tried to build a radio wave transmitter and intercept a radio station by sending radio waves of similar frequency to that of the radio station. I imagine that would be quite a fun thing to do.

More research for scifi stories: What the "theoretical" limits on the size of a radio telescope (assuming great advances in manufacturing techniques and unlimited resources). I know the resolution is dependent on how far apart you place the individual components, so could you in theory have...

I am looking for a radio transmitter to transmit altitude. I don’t need one that comes with an altimeter. The altimeter will change in voltage as altitude changes, so the transmitter just has to transmit that data to a receiver. The transmitter must have a range of atleast 100 kilometers. It...

http://healthandfitness.sympatico.msn.ca/News/ContentPosting.aspx?contentid=85b9ce54b8824e2baa998e79f5ec2f1e&show=True&number=6&showbyline=False&subtitle=&detect=&abc=abc Do radio waves REALLY cause leukemia? Aren't they lower in wavelength than infra-red?

I am somewhat discouraged by my top six car radio selections. One changed from primarily classical to primarily news, duplicating another's National Public Radio and BBC subscriptions. An alternative rock station for 35 years changed to all Spanish popular music programming - maybe I'll pick...

hii guys! I'm having trouble with a homework and I was wondering if you could explain something to me. Here's the problem: Two radio antennas A and B radiate in phase. Antenna B is a distance of X meters to the right of antenna A. Consider point Q along the extension of the line...

Hello, I am having difficulty answering the following problem: consider two antennas, separated by X meters that radiate in phase at f. A reciever placed 150 m from both antennas measures an intensity I_o. The reciever is moved so that it is 1.8 m closer to one antenna than ot the other...

What is RF engineering?

In other medium except vacuum, there is different speed in different EM wave, right? i.e. speed of radio wave is faster than speed of gamma wave, right?

Q. The half life of carbon-14 is 5730 years. If the original amount of carbon-14 in a particular living organism is 20 grams and that found in a fossil is 6 grams. determine the approximate age of the fossil. Here is what I did: A(t) = A0 e^kt 1/2 A0 = A0 e^5730k Find k by taking ln...

Tonight on Coast to Coast they were talking about the old radio and TV series, Space Patrol. I have heard of it once or twice but that's all. Apparently this had a following much like Star Trek, which came much later. Does this bring back memories for anyone? http://www.spacepatrolbook.com/...

A portable radio is sitting at the edge of a balcony 5.1m above the ground. The unit is emitting a sound uniformly in all directions. By accident, it falls from rest off the balcony and continues to play all the way down. A gardener is working in a flower bed directly below the falling unit...

Hi, first time posting, nice forums :) Recently in my preparation for my scholarship exams later this year, i was approached by a question which has me rather confused. Im not neccesarily asking for the final definate answer, but it would be nice for some help on how to approach the...

I'm a high school student working on an extracurricular activity where I'm trying to design and build a radio system to function similar to that of a rc vehicles. However, I'm just getting started, and my knowledge is mostly in mechanical engineering. Where should I start? Thanks

has anyone built this, something similar, or know anything about it? i found it on the internet and decided it was good to build seeing as i already have a satellite dish not being used. does anyone know of anything perhaps better to build? I've never built a radio telescope before, or any...

How to improve FM radio reception? I have this boombox type radio in my room with one meter long telescopic antenna, reception is sometimes really bad. Should I just hook up length of wire to the antenna or what ? Thanks. :smile:

Okay, I guess this falls into the electrical engineering category. Ever since I moved into my house, I've noticed this odd problem of picking up a particular FM radio station on my phone receivers as well as it bleeding through across ALL the FM stations. I only have this problem in my...

What is modulation in radio communication?

I'm curious why can AM radio waves be heard on the other side of a mountain from where they are propogated and FM not? Thanks

http://news.bbc.co.uk/2/hi/technology/4059011.stm

Hello, I was just wondering if anyone around here is a Ham/ interested in amateur radio at all. I got my ticket two years ago when I was sixteen but don't operate much lately due to college and the horrible reception you get in the average dorm. KB3HTS

Ok, so we all know that the shorter the wavelength, the higher the frequency, and the higher the photon energy for EM radiation. How does this relationship explain why X rays are highly dangerous to living things, and radio waves are not? Thanks in advance.

Hey i was wondering if anyone had any sites on how to build a Spark Gap Radio Transmitter, i need to do this for history to show how marconi invented the radio. Thanks- Andrew

Please help with problems please! All questions need to be solved using vectors. See enclosure for questions :biggrin: Thank you! Or go to: http://img128.exs.cx/img128/9089/questions2.jpg

Hi, I'm trying to design a low-cost digital radio interface to communicate with a robot. I'm not interested in exchanging a lot of data, or doing it at high speeds. This design will work well if I can get even 300 baud out of it since I never exchange more than about 1K bytes during a...

if a car with a radio is moving at some speed and it receives radio waves shouldn't these waves get Doppler shifted and the radio signal be disrupted?

There is an archived program of an interview I conducted with Dr. Kaku about a year or so ago. We discussed worm holes, alien life, god, dimensions and more.. Check it out, on the front page here: http://www.infidelguy.com

I just read of an idea to send a craft outside our solar system using the various stellar bodies to sling shot it and also create a way for it to continually accelerate. In which case it would eventually near the speed of light. So in fifty years it could send us pictures and what not of faraway...

I have come to understand the meaning of the terms "am" and "fm" as different kinds of radio emissions. Sadly, I have not understood the meaning of the numbers used to identify certain radio stations. If someone could tell me, it would be fantastic. :smile: I've been dying to know. :-p

Could a crystal radio use a lead sulfide or lead selenide antenna an pick up in the infrared?

Can a crystal types radio be made to work in infrared? With an antenna of lead sulfide or lead selenide perhaps?

How would u make a radio that's tuned into 120.55 Mhz? or any frequency? I thought you would fallow this formula... (120.55 * 10^6 Hz) = 1/(2 pi sqrt(LC)), where L is the inductence, and C the capacitor. well i figured a 1 micro (10^-6) Henry inductor and a 1.743 pF (10^-12) would create...

AM radio -- please help! Hello, Here is some background info. I don't know if it is all necessary to find a solution but here it is anyway: I am currently living in State College, PA. I would like to be able to listen to an AM radio station broadcasting from Philadelphia, PA...

Ok, I saw this guy trying to unlock his car with his radio controlled keyring with no luck, he put the device next to his head and it worked. The keyring was the same distance to the car in both cases give or take 1/4 meter. Would the same happen if you put the keyring next to a conductive metal...

Through my school, I'll be working with a radio telescope. I was wondering if you guys had any ideas or suggestions of cool things that I could research or observe with the radio telescope. Thanks!

has anyone here ever built a crystal radio? what parts would i need and where can i get them? in the physics forum they said one could be constructed to run off the radio waves themselves, which is the kind i would like to build. thanks