Building better High sensitivity headphones

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na

you're evidently not fluent with classical physics either. that's okay, but then you need to listen. we're done explaining anything to you.

r b-j

okay, but then you need to listen. we're done explaining anything to you.

In physics is also the classical optics. There is wrote that the light and the sound are fully analogous.

Maxwell assumed that light is polarized and did proper math for it. There the magnetic substance had mass but electricity is massles and incompressible. But later the electrons were discovered. They have mass and the electron gas is compressible.

You are using electrons. It is not classical electromagnetism. Now the antennas are polarized not waves. One dipole is sending pulses from the two ends. Monopoles from one. Phaze radar from many. If are more sources than one the interference works.

Do not mix the electrons with the classical EM (it was wrote by Heaviside - Maxwell model was quite different)). S*

One thing to consider the population of nearby or powerful AM (or FM) stations in an all-out emergency.

If it's pragmatism you want vs purity, then a solar cell or hand (shaker) generator is the answer to get the flea-power needed to power the average crystal radio set.

Correct. The RF tank for FM will need different wire coil and tuning capacitor (both smaller) and of a greater Q for "slope detection" to work. A relatively high RF tank Q is needed since the FM swing is about 100 kHz while the RF fundamental is about 100 MHz. The Q should be in the hundreds... Whether slope tuning is practical remains to be seen.

That remains to be determined.

Ange

Uh, unless you impedance match, which is common.

I did some correction. Is it better now?

What do you think on this?

"Alejandro Lieber" wrote news:iac90k$57m$ snipped-for-privacy@tioat.net...

Like here:

Will it be work with the diode in reversed direction? S*

On Oct 29, 3:38=A0am, "Szczepan Bialek" wrote: ...

as well as it works with the diode in the direction shown.

dunno how you tune a particular station with such a circuit.

r b-j

Uzytkownik "robert bristow-johnson" napisal w wiadomosci news: snipped-for-privacy@l8g2000yql.googlegroups.com... On Oct 29, 3:38 am, "Szczepan Bialek" wrote: ...

It is a simplst radio. All is wrote here: :

But there the diode is always in series.

It seems that in series " electrons are leaving my hand". DC consists of electrons.

In parallel also? S* P.S. Does the corrections works?

ps.com...

ode

in a practical crystal radio, the diode is in series with the headphones and behind the diode is some sorta "tank circuit" with reactive elements. the crystal set i built when i was a kid in the

the antenna and tank circuit formed an output with sufficiently low series impedance and the headphones had sufficiently high impedance that it mattered little if the diode was conducting or not.

i cannot account for what "seems" to you, but if electrons are leaving your hand at a sufficient rate, you would feel it. if they never returned by a return path, charge would build up in very little time. touch a metal doorknob or ground and you would feel it.

DC is *current*. in normal conduction, it is the movement of free electrons around a *circuit* (and i think that "circuit" means in a circular path of some sort).

it's not DC, but has a DC component. it also has an AC component at audio frequencies and another AC component at the carrier frequency and its harmonics.

dunno what corrections. but i can read your post using Google.

what you need to correct is your misconception that the mechanics of radio transmission and reception somehow involves electrons leaving the transmitting antenna and traveling to the receiving antenna. that's not how it works.

r b-j

headphones and behind the diode is some sorta "tank circuit" with reactive elements. the crystal set i built when i was a kid in the

My older brother built the same 60 years ago.

series impedance and the headphones had sufficiently high impedance that it mattered little if the diode was conducting or not.

your hand at a sufficient rate, you would feel it. if they never returned by a return path, charge would build up in very little time. touch a metal doorknob or ground and you would feel it.

He feels it: " I put up a 200 foot antenna between two trees over my house, and tuned to a 50,000 watt station about 30 miles away, and now I get 175 microamps of current through my meter."

I am interesting in direction only.

electrons around a *circuit* (and i think that "circuit" means in a circular path of some sort).

audio frequencies and another AC component at the carrier frequency and its harmonics.

Oscillations plus pulsatille flow.

radio transmission and reception somehow involves electrons leaving the transmitting antenna and traveling to the receiving antenna. that's not how it works.

And what about this: "The simplest radio is like a photocell. There are the two copper plates with the semiconductor between. Electrons always flow from the side exposed to light to side in shadow. Never in opposite. One plate is working as an antenna and the other as the chassis."

The all is not my conception. For Helmoholtz and Tesla the radio waves are longitudinal. Such waves exhibit the Stokes drift. This names are more famous than Heaviside. S*

ps.com...

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"pulsatille" is not an English word. dunno precisely what it means in French. i get a lotta flowers when i Google the word.

a radio is not only about energy conversion. it is about the wireless conveyance of information. yes, you can use a photocell for a receiver if the transmitter is a keyed (or modulated) lamp of some sort.

it still has nothing to do with clearing up your misconception.

you are fully screwed up. you know little or nothing about the simple physics involved in radio transmission and reception at frequencies less than, say, 300 MHz.

you think that electrons are somehow leaving the transmitting antenna and moving to the receiving antenna. they don't. the cause and effect that provide for the transfer of information is the movement of electrons in the transmitting antenna element which, because of the fundamental interaction of E&M (one of the four fundamental interactions), cause movement of electrons in the element of the receiving antenna.

in a semiconductor photocell, there is a totally different physics going on where a photon sorta dislodges an electron from atoms and a current is formed when that electron (due to the electrostatic potential that results) tries to find its way back home.

i never implied that radio waves were not transversal.

fluff. this has nothing to do with anything regarding a crystal radio.

more name dropping. you really have little idea of what you are writing about.

r b-j

"robert bristow-johnson" wrote news: snipped-for-privacy@j25g2000yqa.googlegroups.com...

properly so that people reading what you post can tell who says what. i fixed in manually in the past, i am not bothering to do it again.

I must add ">" manually to your posts.

wiadomoscinews: snipped-for-privacy@l8g2000yql.googlegroups.com...

French. i get a lotta flowers when i Google the word.

""Unsteady flow is present in man, machine and nature. The flow of blood in arteries and capillaries in the human body is pulsatile- composed of a mean flow superposed with an oscillating component. The tides that wash in and out of rivers, harbors and estuaries are unsteady flows with very long periods of oscillation. Many engineering devices employ pulsatile and oscillating flow. Pulsating flow is defined here as a periodic flow with a net displacement of fluid over each flow cycle. Oscillating flow is defined as a periodic flow with a zero mean over each cycle." From:

Should be pulsatory (probably). The "net displacement of fluid over each flow cycle" is the Stokes drift.

conveyance of information. yes, you can use a photocell for a receiver if the transmitter is a keyed (or modulated) lamp of some sort.

physics involved in radio transmission and reception at frequencies less than, say, 300 MHz.

and moving to the receiving antenna. they don't.

An experiment decides.

effect that provide for the transfer of information is the movement of electrons in the transmitting antenna element which, because of the fundamental interaction of E&M (one of the four fundamental interactions), cause movement of electrons in the element of the receiving antenna.

going on where a photon sorta dislodges an electron from atoms and a current is formed when that electron (due to the electrostatic potential that results) tries to find its way back home.

radio.

A cristal radio is the best tool to measure the ground current (net flow of electrons).

writing about.

I was trying to ask for "net displacement of electrons over each cycle". Without succes. S*

snipped-for-privacy@j25g2000yqa.googlegroups.com...

the correct tense of the word is "decided". settled long ago. air is an insulator. to get electrons to move through it requires ionization of the molecules which will manifest as a very hot arch. if you ever visit Boston, try visiting the Museum of Science and the big Vandergraf generator there. that's when you'll see an experiment of electrons moving through the air.

if you're thinking of becoming a physics prof or even a high school teacher of physics, i wouldn't quit the present job, if i were you.

r b-j

snipped-for-privacy@k22g2000yqh.googlegroups.com...

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oh, i missed this early misconception.

would you be willing to divulge the author and title of an optics textbook that has written inside it that light and sound are fully analogous? i'll put in on a list of textbooks to avoid using for any purpose. (sound waves are longitudinal, but EM radiation are transverse waves.)

light and radio waves are not merely analogous, they are the same thing. the only difference is quantitative and because of that difference, which is significant, the transmitting and receiving apparati is qualitatively different.

there *are* some analogous technologies regarding EM and sound. some of the techniques i had once learned in a class on antenna theory and design (like phased arrays) can also be used for sound (wavefront synthesis for either loudspeaker or microphone arrays).

r b-j

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textbook that has written inside it that light and sound are fully analogous?

Walter Weizel, Lerhbuch der theoretischen physik.

You wrote "there *are* some analogous technologies regarding EM and sound".

I bet that you do not find even one exception.

purpose. (sound waves are longitudinal, but EM radiation are transverse waves.)

For Tesla and many others the electric waves were and are longitudinal.

thing. the only difference is quantitative and because of that difference, which is significant, the transmitting and receiving apparati is qualitatively different.

See "free electron laser". Apparati are the same.

of the techniques i had once learned in a class on antenna theory and design (like phased arrays) can also be used for sound (wavefront synthesis for either loudspeaker or microphone arrays).

You are close to right way. Start with the oryginal Hertz experiment:

EM starts there from current (the place where the sparks are). But Oliver Lodge discowered the standing wave. At the end the voltage is doubled. From the ends the alternate electric field is emitted.

Is Hertz dipole analogous to the two Kundt's tube (loudspeaker array). Is Weizel right? Weizel presents the all theories and evidences (also Michelson-Gale experiment). But without comments. Student should think. S*

an insulator. to get electrons to move through it requires ionization of the molecules which will manifest as a very hot arch.

But now we know that in space is the Interstellar Medium (IMS). Rare plasma

visit Boston, try visiting the Museum of Science and the big Vandergraf generator there. that's when you'll see an experiment of electrons moving through the air.

But in "vacuum" they travel freely. I only do not know why they do not like vacuum. The prefer body. They jump from one to the other. Why they do not stay in vacuum?

teacher of physics, i wouldn't quit the present job, if i were you.

I am a retired engineer. I only want to know the simplest things on electricity. But not in the school version. There the gravity, electricity and magnetism must be seperate. In reality the mechanism must be the same. It is not my opinion. S*

snipped-for-privacy@v20g2000yqb.googlegroups.com...

if that's true (and it's likely it's not), the textbook is not to be depended upon for factuality.

".

how much do you bet? i'll bet US$10000 or any lessor amount above US $500 (the minimum is just to justify the bother). i'm serious. i can get a credit line on our home for at least that amount (in fact, i can just get it from a couple of credit cards). can we find a neutral party where we can both deposit our wager? perhaps Angelo?

you know what? i'll even grant you a 2-to-1 handicap. (i will deposit twice what you do, if you win the bet, you would get twice what i would if i win. think of it, S, you earn an easy US$10000 and all you have to risk is US$5000 which will be returned to you along with what used to be my $10000, if you are so sure of what you say.)

i won't represent (or misrepresent) Tesla, but EM radiation is transversal. every physicist knows that (besides a few engineers). maybe you want to check out the first sentence here:

S, you can name-drop all you want, but you don't know s*it. you are truly what we call here in English-speaking countries a "crackpot" or "crank". your foolishness (and naivete) is manifest for all to see. if you had *any* idea, you would be embarrassed, but you don't even know enough to be embarrassed about the silly things that you continue to say.

unless you're willing to "put your money where your mouth is", i am not willing to continue this foolishness. (but don't quit your day- job if you're thinking of becoming a physicist or any other scientist, or engineer for that matter.)

r b-j

ups.com...

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well, let's see how much conduction you get in space. or in a vacuum created in the lab.

only if they are first freed from the matter the electrons were originally part of (usually thermal energy is used to do that). and when that happens, they will "freely" travel right back to that matter (because it will be left positively charged after the electrons are knocked off of the surface) unless there is an even greater electric field that draws them elsewhere.

do you have any idea how a vacuum tube (what the Brits call a "valve") works? it's a rhetorical question. of course you don't.

i hope no bridges you may have designed have fallen (

no you don't. you want your simple misconceptions about electricity to be reinforced. you clearly are not interested in learning

so you would rather not have your understanding of reality stand up to scrutiny?

so which is it? like-signed charges attract (as do like-signed masses)? or do like-signed masses repel (as do like-signed charges)? even if you're willing to accept the sign change between EM and gravity, have you discovered any negative masses yet?

it is your (and some other crackpots') opinion. it has nothing to do with reality.

r b-j

transversal. every physicist knows that (besides a few engineers). maybe you want to check out the first sentence here:

Here is the Maxwell's model:

And here the Heaviside's:

The both are transversal but they are quite different. In textbooks is Heaviside's. The must be the all theories.

truly what we call here in English-speaking countries a "crackpot" or "crank". your foolishness (and naivete) is manifest for all to see. if you had *any* idea, you would be embarrassed, but you don't even know enough to be embarrassed about the silly things that you continue to say.

not willing to continue this foolishness. (but don't quit your day- job if you're thinking of becoming a physicist or any other scientist, or engineer for that matter.)

Is the pulsatory flow of electrons in a ground cable? S*

(

It was aircraft engines.

to be reinforced. you clearly are not interested in learning

You believe in Heaviside' model. I in Stokes, Helmholtz and Tesla. Take a glance at them. S*