Antenna - Sixty Symbols

[Kurtlane]

I have noticed that all radios get worse and worse reception as time passes (I'm talking years.) More and more noise. Why does it happen?

[2martino3]

I dont understand how there can be so many different signals flying through the air and affecting all antennae, yet we can choose to listen to only one, without interference..

[OOZ662]

@2martino3 Essentially the same way we can take white light (all colors together) and pass it through a filter and get only one color/wavelength out. Though instead of passing it through solid medium, you're futzing with the properties of the antenna/receiver to make it only susceptible to a certain frequency or amplitude.

[RandySilverWolf]

does alternating current occur in nature any at all?

[AndyKong51]

Why does it have to be 1/4 of the wave length?

So the ceramic reduce the wavelength? Will it lose lots of power through this process?

[notapetit]

Where's the extra footage that talks about fractal antennas? :D

[intemister]

this vid was not one of the better ones. sorry :S

[rathat48]

A bucket of Hydrogen? lol

[adrianjcc]

@rathat48 Liquid?

[rathat48]

@adrianjcc That's not what he means and I said lol because it was funny.

[metabog]

I think some people might go ahead and take some of the analogies for truth.

[georgegee12345]

WOOOOO 10,000th view!!!!

[multished]

Why do some ariels have a coil either at the bottom or at the way to the top?

[EquinoxstudiosUK]

Impedance matching. A quarter-wave antenna presents an impedance of 50ohms at its base. It is possible to create variations that exhibit 'gain' by the concentration of energy in 'lobes' that radiate out from the antenna. These variants use different fractions of a wavelength such as 5/8 or 7/8 and present a different impedance to the equipment attached to it. The inductance of a coil in the antenna alters the impedance to become 50ohms which is important to a transmitter output stage.

[tremlin1]

i was so just going to write that O.o

[pamew]

far as I remember, it's just to increase surface area and therefore reception, Of course I could be horribly wrong lol.

[imover18gotityube]

Yes, the coil is an inductor.

[nickthesafe]

It is to increase the electrical length rather then the actual length of the antenna, in order to make it a quarter wave length without being ridiculously long!

[jimbobg65]

A coil in any electronic circuit suppresses higher frequencies, so I'm guessing on an antenna, it would lower interference from things you don't want the system to pick up. i.e. Lightning strikes for one (for low frequency systems in the kHz and low MHz range), or from things like mobile phone masts for instance.

[culwin]

System of a Down, yeah

[OhYeahMilkIt]

i like how he thinks that his arms spread is 2 to 3 meters ) at 7:40

[dradeel]

Hahaha, true :D That looks kinda akward. It could be he's imagining the length of the top of the wave between his hands where his hands would be only two zero crossings, which is half the full wavelength of 2 to 3 meters? I dunno, I'm just throwing him a bone here. Hehehe.

[LaughingManRa]

Nice video. :-)

[yellowlabrador]

A question for you physicists,when I listen to longwave my batteries last longer than if I listen to FM. How come?

[CtrlAltDe1337ed]

Whats the difference??? Is it significant?

[HLSDK]

I'm not sure about physics, but depending on the frequency of usage (lower frequency communications can be SSB), some circuits draw more current at higher frequencies, where FM is usually used. I could be wrong though.

[mundayP22]

At a guess it would be because the only electronics requiring power to receive AM signals is the amp however to receive FM signals you require more electronics to decode the signal and the amp.

[PMGatUoN]

Without looking at the circuit I can only speculate! However an FM decoder will have some extra bits such as a IF (intermediate frequency) stage, local oscillator (for tuning

), discriminator (FM -> audio) and a stereo decoder. These are most likely to be power hungry active components. The audio amplifier is the same for both and the first stage amplifier consumption is probably very similar for both FM and LW. I am pleased that the designer of your radio has turned off the FM when unused

[Myx4o]

Maybe it has something to do with the fact that lower frequency (longer wavelength) transmissions carry less energy and maybe require less energy to turn into sound.

[MichaelKingsfordGray]

In principle, AM and FM should not have any noticeable difference in power consumption.

It is almost undoubtedly due to poor design of the FM section of your set.

BTW: AM transmitters generally xmit at a MUCH higher power level than FM.

Thus a crystal set AM receiver can operate an ear-piece using the power of the transmitter alone, without an amplifier!

[ibrahim1088]

the Electron Spin Resonance (ESR) @ 6:00 is an interesting topic in quantum chem...

[769Del]

1.4GHz? overclock that shizzle :)

[TooMuchButtHair]

The 1.4 GHz isn't referring to a processor speed - it's referring to the frequency of a photon.

[769Del]

Dear me. It was a joke.

[HLSDK]

:-D OVERCLOCK! Use liquid nitrogen :-p

[waterfat]

Y'all are awesome!

[colinstu]

How come some stations might sound a little fuzzy, but if I grab the antenna, it comes through clear? (w/ regular old radio)

Is my body helping pick up signals or something?

[ignilc]

yes, shit works great for picking up signals

[barashah]

yes its ur body because body is conducter it increases the area of antenna hence improving the singal

[nurikosguardian]

i'm going to take a guess and say that your body is probably slightly extending the aerial. Making it easier for the aerial to pick up the wavelength.

[ahaitsrob]

i love these vids :)

[cthulhex]

3:00 Uuuhh.... This reminds me of the Silent Hill radio

[violapie]

My dad used to work on those a few years ago.