Chip with simple program for Toy

[Rod Speed]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote

Rod Speed wrote
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote
Rod Speed wrote
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote
Rod Speed wrote
John Larkin wrote
Eeyore wrote
John Larkin wrote
Rod Speed wrote
John Fields <jfields@austininstruments.com> wrote

And you?

I piss on clowns like you from a great height.

You get to like that or lump it, child.

What could you possibly know about great heights?

I'm hard pressed to tell who's the least imaginative insulter.
Cahill or Speed.

Both are amateurs, at technology and at insulting.

You three clowns in spades.

Oh dear that actually made me laugh out loud.

A brainless jerk insults 3 engineers whose products
have sold in the (most likely tens of ) thousands

Just another pathetic excuse for an insult any 2 year old could leave for dead.

Search ebay for "studiomaster" in my case..

Irrelevant to how pathetic you are at insults, and even very basic
stuff like working out what can be done about terrorists in spades.

The UK found a settlement with the IRA that works and I fully support and you think you know better ?

I know that that approach didnt work with the Irish themselves, hasnt worked with many other terrorists
at all, and that it certainly wouldnt work with the terrorists who are currently a problem either.

In spades with those who are stupid enough to believe the line that blowing themselves
to bits in the right circumstances is an absolutely guaranteed ticket to nirvana.

You're too stupid to be able to work out the difference.

 

[Rod Speed]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote

Rod Speed wrote
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote
Rod Speed wrote
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote
Rod Speed wrote
John Fields wrote

Geez, Mommy, are those the only chices I'm allowed to have?

Yep, and if you dont like it, do the decent thing and hang yourself or sumfin.

You know you're not really very good at this.
I'll have to tell Bertei I've met you.

Just another pathetic excuse for an insult any 2 year old could leave for dead.

I'll be sure to let Bertei know you passed on your regards.

Retake Bullshitting 101, child.

Be sure, he knows you.

Who cares ?

 

[Kris Krieger]

m II <c@in.the.hat> wrote in news:wc7lk.3500$%b7.452@edtnps82:

Kris Krieger wrote:

m II <c@in.the.hat> wrote in news:jb%kk.3639$nu6.3165@edtnps83:

z wrote:

who uses a PC to plow their field? seems inefficient.

Actually, if it weren't for the rocks, we would get more of them.

http://www.johndarwell.com/projects/s_nsfh3/index.php?i=11

Heh

What's with the traffic cone BTW - was it that "done up" that way and p
ut
there by the sea/weather...? Strange thing, that.


It seems to be a tribute to our stewardship of the planet.



mike

Yes, but I was asking, Was it was made up by a person and placed there, or
was it was weather-created and the photographer found it like that? Just
curious.

 

[Rod Speed]

Some terminal fuckwit claiming to be
John Fields <jfields@austininstruments.com> wrote just the
usual pathetic excuse for a troll thats all it can ever manage.

 

[Rod Speed]

John Fields <jfields@austininstruments.com> wrote

Rod Speed <rod.speed.aaa@gmail.com> wrote
John Fields <jfields@austininstruments.com> wrote
Rod Speed <rod.speed.aaa@gmail.com> wrote
John Fields <jfields@austininstruments.com> wrote
Rod Speed <rod.speed.aaa@gmail.com> wrote
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote
Rod Speed <rod.speed.aaa@gmail.com> wrote
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote
Bret Cahill <BretCahill@aol.com> wrote
John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote
Bret Cahill wrote

Everyone's seen that stuff 8 billion times.

Are you trying to bore everyone to death or what?

OK, show us something interesting that you've done.

I'm constantly posting ideas, especially in the summer.

Ideas are wonderful; the more the better. But they have to be
sifted by reality, lest they just be a heap of noise. And occasionally
turned into real stuff to add a little feedback to the process.

It's rewarding to have an idea, make it actually work, and sell
it to people who appreciate it. Call it insecurity, but seeing the
ideas out there working, for serious people, is awfully validating.

Only the pathetically insecure actually need any 'validating'

If nobody buys your stuff, that's OK with you?

Yep, if I know that its a good idea. I dont care whether anyone else agrees or not.

So you and your good idea get to die in the dark

Never said anything like that. You dont have to turn the idea
into a viable product yourself for it to be a worthwhile idea.

Never said you did. What I said is that if you don't share
the idea then it's going to go to the grave with you

We werent discussing not sharing the idea, you pathetic excuse for a bullshit artist.

What was being discussed was whether an worthwhile idea needs to
be VALIDATED by producing a product that corporates choose to buy.

No,

Yep.

what was being discussed is the validation that _people_ feel when
a good idea is turned into reality and appreciated by serious people.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs>

and you will have cheated mankind out of something worthwhile.

Nope, most obviously if someone else also comes up with that idea later.

Some things never come back once they're lost.

Thats never ever true of any idea that matters.

instead of getting proliferated for your good and that of all mankind?

Plenty of ideas are nothing like that.

Got an example or two?

The idea that you can con some fools into believing that that if
they blow themselves to bits in the right circumstances that that
will be an instant transport to nirvana is one obvious example.

Well, we were talking about _good_ ideas that are lost because
of the reticence of the thinker to share them, for whatever reason,

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

so your example is clearly out of the scope of the discussion.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

Religion is repleat with examples of ideas that are bad for mankind.

What?

You deaf ?

The idea that it's bad to commit murder, or lie, or steal is bad for mankind?

Never ever said anything even remotely resembling anything like that, you pathetic excuse for a lying bullshit artist.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

That's pretty damned selfish, I'd say,

Have fun thrashing that straw man ?

It's not a straw man, it's the point.

Its a straw man.

Moreover, your impugning it as being a straw man _is_ a straw man.

Pathetic. You wouldnt know what a real straw man was if one bit you on your lard arse.

Well, then, explain how my statement was a straw man.

You're too stupid to understand the anwer.

since all you get if you do it that way is to suck
tour thumb and watch the world die around you.

Not if someone else chooses to use the idea.

But you have to SHARE it for that to happen

And we werent discussing not SHARING it, we were discussing
whether producing a product that uses that idea and flogging it
to a corporate VALIDATES the idea. Of course it doesnt.

validating the _idea_ wasn't what was being discussed,

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

the feelings of validation experienced by the thinker-upper of the idea were.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

and you stated earlier:

"Only the pathetically insecure actually need any 'validating'"

Clearly nothing to do with SHARING.

and:

"Yep, if I know that its a good idea. I dont care whether anyone else agrees or not."

Which indicates to me that you won't share the idea

More fool you. We were clearly discussing the Brat sharing ideas.

Do try to keep up.

Not even possible to keep up with your pathetic excuse for lying bullshit.

The thread meandered away from that quite a while ago.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

because that'll compromise your sense of "No validation required".

Pathetic.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

I love it when Pratt&Whitney or McDonald Douglas or Rolls Royce or the Skunk
Works picks my stuff over somebody else's. Is that pathetically insecure?

Yep, particularly when anyone with a clue realises that corporates
can pick things for completely silly bureaucratic reasons.

Like _you've_ got a clue?

Any 2 year old could leave that for dead.

But you can't.

Just did.

Did not, doom-doom head.

Any 2 year old could leave that for dead.

Get one to help you before posting again.

If anyone is actually stupid enough to let you anywhere near one.

Tell us about your life in corporate America
and how you know that what you claim is true.

Dont need to have anything like that to see that that particular claim is true.

If you haven't "Been there, done that." then it's all hearsay.

Wrong again. Thats not what hearsay is.

Where did you hear that?

Usual place, a dictionary. Try it some time.

History is riddled with examples of footshot after footshot after footshot
where corporates have been too stupid to know a good idea when they
see one and where they ignore a good idea because it would cripple
the prospects for their current offers in the market etc.

Hindsight's 20-20, isn't it?

Taint hindsight either. Just history.

Of course it's history, That's blatantly obvious but your claim that:
"Geez, they shouldn't have done it that way." is _precisely_ hindsight.

Pity that was never ever my claim, you pathetic excuse for a lying bullshit artist.

If exploiting an idea would endager their position in
the marketplace, then they'd have to be daft to try it.

But that does mean that if they decide that they arent interested
in your idea, that that does NOT mean that the idea is invalid,
just that they are have their own agenda and that they are
irrelevant as far as whether your idea is worthwhile or not.

Again, the subject at hand is _not_ validation of the idea,

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

it's validation of the person who generated the idea.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

Besides, "Ignore" is hardly the right word since if an idea is presented
and subsequently rejected, it's still been acknowledged as an idea.

We're discussing VALIDATION of an idea. If its ignorned, it aint been VALIDATED.

No.

Yep.

Were discussing validating the generator of the idea, not the idea itself.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

Oh, and while you're at it, tell us about your experiences regarding
electronic circuit design and how you've made a difference, OK?

None of your business.

Translation: "I don't have a clue."

Any 2 year old could leave that for dead.

What do you mean?

Pathetic.

If you've got a clue, you know if your idea is any good.

Nope,

Yep.

Nope.

Yep.

There's many a slip 'twixt the cup and the lip,

Irrelevant to whether its a worthwhile idea or not.

Hardly.

Fraid so.

if it's a worthwhile idea then its worth will be borne out with its successful execution.

Doesnt have to be by the individual that produced the idea, you pathetic excuse for a bullshit artist.

If it's found to be unexecutable then it's a bad idea.

Not if that problem isnt permanent.

An example in that direction might be: "I have this great idea!
Everything revolves around the Earth!" Initially a great idea.
As time went by, not so great.

Thats not an idea that can be turned into a product and flogged
to a corporate, you pathetic excuse for a bullshit artist.

In the other direction, Feynman was initially ridiculed for his
views re. quantum electrodynamics, but as time went by he
was vindicated and his "bad" idea became an excellent one.

And that did not require any product that could be flogged to a
corporate to validate it, you pathetic excuse for a bullshit artist.

so even if you've got a clue there's no telling whether
the idea is good or not unless it's reduced to practice,

Wrong again.

Nope.

Yep.

There's been many who have come up with a good idea
who arent capable of turning that into a viable product.
Its still a good idea even if they cant and someone else
can turn it into a viable product.

We're not talking about whether it can be made to work by _someone_,
we're taking about it being a bad idea if it can't be made to work by anyone.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

But, we're getting off the subject here, the subject being the validation
of the originator of the idea, not the validation of the idea itself.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

even if that "practice" has to be a thought experiment.

Just as true even with that.

So you're agreeing with me about something?

Pathetic.

unless all you care about it is for your own use.

Wrong, as always.

Your word is hardly sacrosanct, so have you got some proof?

How odd that we havent seen a shred of that from you.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

You dont need someone to 'validate' that.

That's not true in the private sector,

Wrong again. Most obviously when someone else uses a worthwhile idea.

If someone else uses it, then you must admit that it has to be shared to be brought to fruition,

We werent discussing sharing, we were discussing whether
you need to turn it into a viable product that some corporate
chooses to buy to VALIDATE and idea. Of course you dont.

Once again, <YAWN> we weren't discussing validation of the
idea, we were discussing the feelings of validation experienced
by the originator of the idea when that idea was successfully
brought to fruition and appreciated by serious people.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.

and the validation occurs when it's proven to work.

Yep, unlike Larkin's silly claim about turning it into a viable product
yourself and getting a corporate interested in that product.

And even with someone else choosing to use an idea, only the pathetically
insecure need that to happen to 'validate' what is a useful idea. Its STILL a
useful idea even if you're the only one that ever gets to hear about it.

Larkin wasn't talking about that, he was talking about the
feeling of satisfaction (elation, even, if the path to the summit
is difficult) one feels when one's ideas are translated into
reality and they work and are acknowledged as being
worthwhile by people who know what they're talking about.

Everyone can see for themselves that you are lying, you pathetic excuse for a bullshit artist.


<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

where sales are validation.

Only for narrow focused fools that are pathetically insecure.

I'd say that exactly the opposite is true,

Your problem.

In what respect?

Pathetic.

considering the amount of effort and risk that's involved
in fleshing out an idea and bringing it to the marketplace.

It aint just about the marketplace. Plenty of the most
important ideas dont involve the marketplace at all.

Well, even your last cockamamie example about some
jihadope blowing himself to smithereens involved some
explosives, and where do you think they came from?

Who cares ?

In some cases they make them themselves, you pathetic excuse for a bullshit artist.

Certainly not an exercise for the faint of heart,

Its got nothing to do with hearts.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

a set of which you seem to be a member.

Any 2 year old could leave that for dead.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

How do you feel about atheletes who want to win an Olympic Gold, or the Super Bowl?

I've always believed that all competitive sports were completely stupid.

Those who participate in them in spades.

And yet, here you are on USENET, running the race of your life
and trying to prove that you're right and everyone else is wrong.

Just another of your pathetic little drug crazed fantasys/pathetic excuse for a troll.

Hardly,

Fraid so.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

since you seem to be the one tugging on the hook.

Just another of your pathetic little drug crazed fantasys.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

Are they pathetically insecure?

Yep, in spades.

I think not.

Thats the only thing you did manage to get right. Nothing to 'think' with.

Well, that was marginally clever, for a change.

Unlike your juvenile shit.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

They have the balls to believe they're the best

Or are drugged to the gills to try to cheat the system.

You elieve that everyone is guilty until proven innocent, eh?

Nope.

Then why would you assume they're all "drugged to the gills" with no proof?

Never ever did anything of the sort, you pathetic excuse for a lying bullshit artist.

and aren't afraid to put it all on the line to prove it.

And you?

I piss on clowns like you from a great height.

Sounds like a mescaline induced hallucination to me.

You'd be the expert on those.

Yup, that's how I spotted it.

You get to like that or lump it, child.

Geez, Mommy, are those the only chices I'm allowed to have?

Yep, and if you dont like it, do the decent thing and hang yourself or sumfin.

<reams of your pathetic excuse for lying bullshit that any 2 year old could leave for dead flushed where it belongs

 

[Rod Speed]

Some terminal fuckwit claiming to be
John Fields <jfields@austininstruments.com> wrote just the
usual pathetic excuse for a troll thats all it can ever manage.

 

[Phil Allison]

"Dave, I can't do that"

I am new to tis group but I have built a lot of kits over the years so
I am not all that new to soldering.

I have a small project with a 555 and about 10 other parts. It is a
very basic 5v, 5KHz PWM circuit. I have downloaded Eagle Lite but the
learning curve is too steep for something I probably will never use
again.

Is there anyone here who could make some changes to a schematic and
then layout a board for Toner transfer and etching.

** Have you never heard of Veroboard ??

http://en.wikipedia.org/wiki/Stripboard

Take me about 15 minutes to have that circuit up and working.



...... Phil

 

[christofire]

<jimp@specsol.spam.sux.com> wrote in message
news:3e6fm5-ru4.ln1@mail.specsol.com...

In sci.physics christofire <christofire@btinternet.com> wrote:

- snip -

The field from a real radiator approaches following the inverse
square law as the distance increases such that the divergence
approaches that of a point source.

Given a good enough beam former, that distance may become an
astronomical
distance.

The collimating characteristics of many antennas are such that you can
not be on this planet and be far enough away to have enough divergence
to approximate inverse square law behavior.

Jim Pennino


Sorry ... you have a screw loose.

Chris

Sorry you can't understand junior high school geometry.

Let's try it this way:

The inverse square law is predicated upon radiation from a point
source.

Any radiator with real area doesn't become a point until you are an
infinite distance from it.

Therefor, for a real area at less than an infinite distance, the
inverse square law is an approximation to what really happens.

The quality of the approximation depends on the real area and the
distance from it.

Got it now?

Jim Pennino

Radiation from an aperture antenna is a matter of diffraction. At any point
of inspection, the field strength (and therefore the PFD) is the result of
integrating contributions from the distribution of current in the aperture.
If it's a one-dimensional aperture, like a thin wire dipole, then the
integral is over that one dimension; if it's a two-dimensional aperture,
like a dish, the integral is over both dimensions. This is a little more
complicated than 'high school geometry' but the calculus involved can often
be kept quite simple - it all depends on the form of the current
distribution.

Away from the antenna, simple geometry indicates that the path lengths over
which the different components act are different, so the result of the
integral will depend on the distance between the point of inspection and the
antenna. However, it has been found for many practical implementations of
dish, etc., that when the difference between path lengths from the centre
and edges of the (normal) aperture is one sixteenth of the wavelength then
the result is essentially independent of the distance. The distance at
which this condition is achieved is the well-known yardstick 2D^2/lambda,
and, for example, this equates to 360 metres for a 3 metre diameter dish
working at 6 GHz; perhaps the largest size used for terrestrial microwave
links. Therefore, radiation pattern measurements need to be carried out
using a measurement range at least this long for the patterns to be
generally applicable.

Of course you have the prerogative to apply different interpretations of the
physics to your own experiments and if your interpretation brings theory and
practice together for the general case then it has some validity. What I've
described above is a small part of the physics that's actually used in the
design of communication links, broadcasting, radar, etc. There are
well-known simplifications like 'ray optics' that neglect diffraction
phenomena, but these are strictly applicable only to the case of
infinitesimal wavelength, so they might be useable in optics but they cause
approximation when applied to systems with apertures of only 60
wavelengths - the above example. When the radiation from a dish is
predicted using ray optics, the ray paths from the feed to the reflector all
end up parallel in the aperture so this gives the impression of a
'collimated' parallel-sided beam ... but this is a major approximation and
is certainly not what is measured in practice.

Chris

 

[Bob Masta]

On Sat, 2 Aug 2008 08:21:25 -0700 (PDT), "Dave.H"
<the1930s@googlemail.com> wrote:

I want to build a headphone amp to connect to my laptop's audio
output, and thought a tube based one would be a nice change from all
the IC driven ones I've built in the past. I would prefer a simple one
with low cost components, and low voltage operation, if possible, and
no more than 3 tubes. Any tube type will do.

Thanks
Dave
Australia

Dave, you might be interested in AudioXpress magazine
(www.audioxpress.com). It's mostly a print magazine, with a few
on-line articles, and I don't know about availability in Australia.
However, it has plenty of tube projects, along with speaker design and
other audiophile stuff. Many of the projects use expensive parts,
but there are a fair number of cheap-and-simple projects. I don't
recall (off the top of my head) about simple *low voltage* tube
headphone amps, but there have certainly been simple tube headphone
amps in the last few years.

Best regards,


Bob Masta

DAQARTA v4.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
FREE Signal Generator
Science with your sound card!

 

[Bob Masta]

On 3 Aug 2008 10:36:45 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2008-08-03, Dave, I can't do that <davenpete@gmail.com> wrote:

I am new to tis group but I have built a lot of kits over the years so
I am not all that new to soldering.

I have a small project with a 555 and about 10 other parts. It is a
very basic 5v, 5KHz PWM circuit. I have downloaded Eagle Lite but the
learning curve is too steep for something I probably will never use
again.

Is there anyone here who could make some changes to a schematic and
then layout a board for Toner transfer and etching. I have an
extensive hobby metalworking machine shop at home and can offer
machining for a prototype in return.

I have the original schematic and the list of changes needed.

if you only want one, and only have about 30 endpoints why not
use a permanent marker on the board and then etch, or as Phil
suggests, just use stripboard.

Bye.
Jasen

I'll second the permanant marker approach. Full details with hints
and tips at:
www.daqarta.com/lptxh.htm

This is a very old page, and I just noticed that the "Resources"
section still contains a link to Kepro. (Belly-up, AFAIK) Other than
that, I think everything is still relevant.

Best regards,


Bob Masta

DAQARTA v4.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
FREE Signal Generator
Science with your sound card!

 

In sci.physics christofire <christofire@btinternet.com> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:3e6fm5-ru4.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

- snip -

The field from a real radiator approaches following the inverse
square law as the distance increases such that the divergence
approaches that of a point source.

Given a good enough beam former, that distance may become an
astronomical
distance.

The collimating characteristics of many antennas are such that you can
not be on this planet and be far enough away to have enough divergence
to approximate inverse square law behavior.

Jim Pennino


Sorry ... you have a screw loose.

Chris

Sorry you can't understand junior high school geometry.

Let's try it this way:

The inverse square law is predicated upon radiation from a point
source.

Any radiator with real area doesn't become a point until you are an
infinite distance from it.

Therefor, for a real area at less than an infinite distance, the
inverse square law is an approximation to what really happens.

The quality of the approximation depends on the real area and the
distance from it.

Got it now?

Jim Pennino

Radiation from an aperture antenna is a matter of diffraction. At any point
of inspection, the field strength (and therefore the PFD) is the result of
integrating contributions from the distribution of current in the aperture.
If it's a one-dimensional aperture, like a thin wire dipole, then the
integral is over that one dimension; if it's a two-dimensional aperture,
like a dish, the integral is over both dimensions. This is a little more
complicated than 'high school geometry' but the calculus involved can often
be kept quite simple - it all depends on the form of the current
distribution.

Away from the antenna, simple geometry indicates that the path lengths over
which the different components act are different, so the result of the
integral will depend on the distance between the point of inspection and the
antenna. However, it has been found for many practical implementations of
dish, etc., that when the difference between path lengths from the centre
and edges of the (normal) aperture is one sixteenth of the wavelength then
the result is essentially independent of the distance. The distance at
which this condition is achieved is the well-known yardstick 2D^2/lambda,
and, for example, this equates to 360 metres for a 3 metre diameter dish
working at 6 GHz; perhaps the largest size used for terrestrial microwave
links. Therefore, radiation pattern measurements need to be carried out
using a measurement range at least this long for the patterns to be
generally applicable.

Of course you have the prerogative to apply different interpretations of the
physics to your own experiments and if your interpretation brings theory and
practice together for the general case then it has some validity. What I've
described above is a small part of the physics that's actually used in the
design of communication links, broadcasting, radar, etc. There are
well-known simplifications like 'ray optics' that neglect diffraction
phenomena, but these are strictly applicable only to the case of
infinitesimal wavelength, so they might be useable in optics but they cause
approximation when applied to systems with apertures of only 60
wavelengths - the above example. When the radiation from a dish is
predicted using ray optics, the ray paths from the feed to the reflector all
end up parallel in the aperture so this gives the impression of a
'collimated' parallel-sided beam ... but this is a major approximation and
is certainly not what is measured in practice.

Chris

The inverse square law is predicated upon a spherical wave front.

A true spherical wave front is obtained only from a point source.

Point sources don't exist in the real world.

At sufficient distance, the difference between the real wave front and
a true spherical wave front approaches the limits of measurment, and
therefor the inverse square law provides a value indistiguisable by
MEASUREMENT from the "real" value at sufficient distance.

The use of the inverse square law is always an approximation in the
real world, though granted sometimes a very good approximation.

The inverse square law is a THEORETICAL relationship and 2D^2/lambda
is a PRACTICAL rule of thumb.

Got the point yet?


--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Jasen Betts <jasen@xnet.co.nz> wrote:

On 2008-08-02, jimp@specsol.spam.sux.com <jimp@specsol.spam.sux.com> wrote:
In sci.physics Benj <bjacoby@iwaynet.net> wrote:
On Aug 2, 11:25?am, j...@specsol.spam.sux.com wrote:

The inverse square law applies to isotropic radiators. No real world
RF antenna is an isotropic radiator.
The inverse square law applies to anisotropic radiators, too.

So you are saying a perfectly collimated beam follows the inverse
square law?

Yes, he is, Jim! And the reason for that is because a "perfectly
collimated" beam simply does not exist!

It certainly does mathematically.

only if it has infinite width.

Which is quite possible mathematically.

consider the difraction that when your perfectly collimated beam passes
through an aperature that exactly matches its size

contrast that with what happens when it doesn't.

Bye.
Jasen

Concider what happens when the perfectly collimated beam impacts a
half gallon of Chunky Monkey ice cream.

However, I'm not sure what either has to do with a wave front propogating
in free space.

--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Benj <bjacoby@iwaynet.net> wrote:

On Aug 3, 1:05?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Jasen Betts <ja...@xnet.co.nz> wrote:



On 2008-08-02, j...@specsol.spam.sux.com <j...@specsol.spam.sux.com> wrote:
In sci.physics Benj <bjac...@iwaynet.net> wrote:
On Aug 2, 11:25?am, j...@specsol.spam.sux.com wrote:

The inverse square law applies to isotropic radiators. No real world
RF antenna is an isotropic radiator.
The inverse square law applies to anisotropic radiators, too.

So you are saying a perfectly collimated beam follows the inverse
square law?

Yes, he is, Jim! ?And the reason for that is because a "perfectly
collimated" beam simply does not exist!

It certainly does mathematically.
only if it has infinite width.

Which is quite possible mathematically.

consider the difraction that when your perfectly collimated beam passes
through an aperature that exactly matches its size
contrast that with what happens when it doesn't.
Bye.
? ?Jasen

Concider what happens when the perfectly collimated beam impacts a
half gallon of Chunky Monkey ice cream.

However, I'm not sure what either has to do with a wave front propogating
in free space.

Has everything to do with it. Mathematics is not "reality".

Bingo, you finally got the point, almost.

Theoretical mathematics is not reality and the inverse square law is
theoretical mathematics.


--
Jim Pennino

Remove .spam.sux to reply.

 

[Tom Biasi]

"Dave, I can't do that" <davenpete@gmail.com> wrote in message
news:a7607a2f-07b6-4055-8199-e40ddd95f423@a21g2000prf.googlegroups.com...

Hi,

I have a circuit that calls for TLC555 and I have about a zillion
NE555.

Why couldn't I use the NE in place of the CMOS version?

Thanks

Dave

I don't know why, I can't see your circuit.
NE needs 5 Volts and has a lower Fmax. if that matters.

Tom

 

[christofire]

<jimp@specsol.spam.sux.com> wrote in message
news:0o4hm5-fm1.ln1@mail.specsol.com...

In sci.physics christofire <christofire@btinternet.com> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:3e6fm5-ru4.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

- snip -

Radiation from an aperture antenna is a matter of diffraction. At any
point
of inspection, the field strength (and therefore the PFD) is the result
of
integrating contributions from the distribution of current in the
aperture.
If it's a one-dimensional aperture, like a thin wire dipole, then the
integral is over that one dimension; if it's a two-dimensional aperture,
like a dish, the integral is over both dimensions. This is a little more
complicated than 'high school geometry' but the calculus involved can
often
be kept quite simple - it all depends on the form of the current
distribution.

Away from the antenna, simple geometry indicates that the path lengths
over
which the different components act are different, so the result of the
integral will depend on the distance between the point of inspection and
the
antenna. However, it has been found for many practical implementations
of
dish, etc., that when the difference between path lengths from the centre
and edges of the (normal) aperture is one sixteenth of the wavelength
then
the result is essentially independent of the distance. The distance at
which this condition is achieved is the well-known yardstick 2D^2/lambda,
and, for example, this equates to 360 metres for a 3 metre diameter dish
working at 6 GHz; perhaps the largest size used for terrestrial microwave
links. Therefore, radiation pattern measurements need to be carried out
using a measurement range at least this long for the patterns to be
generally applicable.

Of course you have the prerogative to apply different interpretations of
the
physics to your own experiments and if your interpretation brings theory
and
practice together for the general case then it has some validity. What
I've
described above is a small part of the physics that's actually used in
the
design of communication links, broadcasting, radar, etc. There are
well-known simplifications like 'ray optics' that neglect diffraction
phenomena, but these are strictly applicable only to the case of
infinitesimal wavelength, so they might be useable in optics but they
cause
approximation when applied to systems with apertures of only 60
wavelengths - the above example. When the radiation from a dish is
predicted using ray optics, the ray paths from the feed to the reflector
all
end up parallel in the aperture so this gives the impression of a
'collimated' parallel-sided beam ... but this is a major approximation
and
is certainly not what is measured in practice.

Chris

The inverse square law is predicated upon a spherical wave front.

A true spherical wave front is obtained only from a point source.

Point sources don't exist in the real world.

At sufficient distance, the difference between the real wave front and
a true spherical wave front approaches the limits of measurment, and
therefor the inverse square law provides a value indistiguisable by
MEASUREMENT from the "real" value at sufficient distance.

The use of the inverse square law is always an approximation in the
real world, though granted sometimes a very good approximation.

The inverse square law is a THEORETICAL relationship and 2D^2/lambda
is a PRACTICAL rule of thumb.

Got the point yet?

Jim Pennino

Well one sixteenth of a wavelength is pretty close to uniform in my book!
All antennas exhibit some sort of phase centre, although for some it may
appear diffuse when inspected at close range, but at distances further than
that practical yardstick the deviation from a perfect spherical wave is
small enough to be found _utterly insignificant_ in practice. Indeed, it
follows that practical antennas do behave _sufficiently_ like point sources
when inspected from a distance (>2D^2/lambda), albeit
not-necessarily-isotropic ones. So link budgets for practical terrestrial
and satellite microwave links have always been planned using the inverse
square law and have always used radiation patterns measured beyond the
yardstick distance (or measured closer and the results transformed to the
'far field'), and these patterns have always exhibited finite beamwidths and
sidelobes. The proprietors of such links have found this method of planning
to be accurate and repeatable, and the sizes of dishes (etc.) have correctly
been chosen to achieve the required coverage areas, to yield the required
signal-to-noise ratios, and so on.

I'm afraid my understanding is rooted in practical applications of the
physics and you will never convince me that a practical microwave antenna
can generate an ideal collimated beam, having a beamwidth of zero degrees
and no sidelobes, or that a practical microwave link can be planned without
using the inverse-square law, which you appeared to state and was the point
about which I entered this thread. I suspect there are many others who read
this Usenet group who share my understanding.

Please let this disagreement rest now. I have tried hard to retain
objectivity but I fear if this branch to this thread is taken further along
the same lines my objectivity may give way to facetiousness.

Chris

 

In sci.physics christofire <christofire@btinternet.com> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:0o4hm5-fm1.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:3e6fm5-ru4.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

- snip -

Radiation from an aperture antenna is a matter of diffraction. At any
point
of inspection, the field strength (and therefore the PFD) is the result
of
integrating contributions from the distribution of current in the
aperture.
If it's a one-dimensional aperture, like a thin wire dipole, then the
integral is over that one dimension; if it's a two-dimensional aperture,
like a dish, the integral is over both dimensions. This is a little more
complicated than 'high school geometry' but the calculus involved can
often
be kept quite simple - it all depends on the form of the current
distribution.

Away from the antenna, simple geometry indicates that the path lengths
over
which the different components act are different, so the result of the
integral will depend on the distance between the point of inspection and
the
antenna. However, it has been found for many practical implementations
of
dish, etc., that when the difference between path lengths from the centre
and edges of the (normal) aperture is one sixteenth of the wavelength
then
the result is essentially independent of the distance. The distance at
which this condition is achieved is the well-known yardstick 2D^2/lambda,
and, for example, this equates to 360 metres for a 3 metre diameter dish
working at 6 GHz; perhaps the largest size used for terrestrial microwave
links. Therefore, radiation pattern measurements need to be carried out
using a measurement range at least this long for the patterns to be
generally applicable.

Of course you have the prerogative to apply different interpretations of
the
physics to your own experiments and if your interpretation brings theory
and
practice together for the general case then it has some validity. What
I've
described above is a small part of the physics that's actually used in
the
design of communication links, broadcasting, radar, etc. There are
well-known simplifications like 'ray optics' that neglect diffraction
phenomena, but these are strictly applicable only to the case of
infinitesimal wavelength, so they might be useable in optics but they
cause
approximation when applied to systems with apertures of only 60
wavelengths - the above example. When the radiation from a dish is
predicted using ray optics, the ray paths from the feed to the reflector
all
end up parallel in the aperture so this gives the impression of a
'collimated' parallel-sided beam ... but this is a major approximation
and
is certainly not what is measured in practice.

Chris

The inverse square law is predicated upon a spherical wave front.

A true spherical wave front is obtained only from a point source.

Point sources don't exist in the real world.

At sufficient distance, the difference between the real wave front and
a true spherical wave front approaches the limits of measurment, and
therefor the inverse square law provides a value indistiguisable by
MEASUREMENT from the "real" value at sufficient distance.

The use of the inverse square law is always an approximation in the
real world, though granted sometimes a very good approximation.

The inverse square law is a THEORETICAL relationship and 2D^2/lambda
is a PRACTICAL rule of thumb.

Got the point yet?

Jim Pennino

Well one sixteenth of a wavelength is pretty close to uniform in my book!

Yes, it is pretty close, but it isn't EXACT, is it?

That's the point.

All antennas exhibit some sort of phase centre, although for some it may
appear diffuse when inspected at close range, but at distances further than
that practical yardstick the deviation from a perfect spherical wave is
small enough to be found _utterly insignificant_ in practice. Indeed, it
follows that practical antennas do behave _sufficiently_ like point sources
when inspected from a distance (>2D^2/lambda), albeit

Yes, the difference falls below the measurement level under some set
of conditions, but it isn't EXACT, is it?

not-necessarily-isotropic ones. So link budgets for practical terrestrial
and satellite microwave links have always been planned using the inverse
square law and have always used radiation patterns measured beyond the
yardstick distance (or measured closer and the results transformed to the
'far field'), and these patterns have always exhibited finite beamwidths and
sidelobes. The proprietors of such links have found this method of planning
to be accurate and repeatable, and the sizes of dishes (etc.) have correctly
been chosen to achieve the required coverage areas, to yield the required
signal-to-noise ratios, and so on.

I'm afraid my understanding is rooted in practical applications of the
physics and you will never convince me that a practical microwave antenna
can generate an ideal collimated beam, having a beamwidth of zero degrees
and no sidelobes, or that a practical microwave link can be planned without
using the inverse-square law, which you appeared to state and was the point
about which I entered this thread. I suspect there are many others who read
this Usenet group who share my understanding.

My whole point is that the inverse square law is an EXACT theoretical
relationship that is APPROACHED in the real and practical world, but
is by no means universally applicable in the real and practical world
under all conditions.

Please let this disagreement rest now. I have tried hard to retain
objectivity but I fear if this branch to this thread is taken further along
the same lines my objectivity may give way to facetiousness.

Chris

I'm just totally amazed so many people seem to have a problem distinguishing
between the exact, theoretical, mathematical world and the real, practical,
world where an approximation is sufficient to build something.

--
Jim Pennino

Remove .spam.sux to reply.

 

[Rod Speed]

Some terminal fuckwit claiming to be
John Fields <jfields@austininstruments.com> wrote
just the juvenile shit thats all it can ever manage.

 

[Rod Speed]

BretCahill@peoplepc.com wrote:

InnoCentive found that “the further the problem was from
the solver’s expertise, the more likely they were to solve it,”
often by applying specialized knowledge or instruments
developed for another purpose.

Maybe it would be better to say the more stunning
the breakthrough the more dissimilar the fields.

Or maybe thats mindlessly silly. Didnt happen with the stunning
breakthrus of the industrial revolution, discovery of electricity,
evolution, working out what DNA is about, the invention of the
transistor, or the integrated circuit, or radio, or TV or
photography or movies or the PC or the net either.

A chemist came up with the MRI.

A PHYSICAL chemist. Thanks for that completely superfluous proof that
you dont have a clue about how broad the field of chemistry actually is.

Einstein came up with the Freon based cooling system which
is considered more mechanical engineering that atomic physics.

Hardly surprising given that he was initially employed in the patent office.

There are endless other examples

Pity neither of those is one of them.

so we know it happens.

Nothing like your original silly claim about the MORE STUNNING BREAKTHRUS.

We need to get some stats on how often

YOU made the stupid claim.

YOU get to do that.

THATS how it works.

and turn interdisciplinarity itself into a science.

You'll end up completely blind if you dont watch out, child.

 

[christofire]

<jimp@specsol.spam.sux.com> wrote in message
news:ltdhm5-5tf.ln1@mail.specsol.com...

In sci.physics christofire <christofire@btinternet.com> wrote:
jimp@specsol.spam.sux.com> wrote in message
news:0o4hm5-fm1.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

jimp@specsol.spam.sux.com> wrote in message
news:3e6fm5-ru4.ln1@mail.specsol.com...
In sci.physics christofire <christofire@btinternet.com> wrote:

- snip - snip -


I'm just totally amazed so many people seem to have a problem
distinguishing
between the exact, theoretical, mathematical world and the real,
practical,
world where an approximation is sufficient to build something.

--
Jim Pennino

You're the one who wrote: 'it is practical to generate a beam that over the
distances of interest is collimated well enough that the inverse square law
does not strictly apply. Most real microwave links are that way' ... which
is incorrect

.... and: 'What I have never done is have occasion to use the inverse square
law in an RF link calculation'

.... both of _your_ statements seemingly relating to the 'real, practical
world' and not 'the exact, theoretical, mathematical world' but applying
nonsensical notions of perfectly collimated beams from antennas. So it
seems the problem distinguishing between those two worlds is yours alone!

Over and out.

Chris

 

[Rod Speed]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote

John Fields wrote

"It's rewarding to have an idea, make it actually work, and sell
it to people who appreciate it. Call it insecurity, but seeing the
ideas out there working, for serious people, is awfully validating."

I have to say that (for example) when I see my high power audio amps
sitting in an amp rack - at least 10 yrs old in my local venue and still
performing flawlesslessly day in, day out - it does give me some satisfaction.

Thats not an idea, thats just routine engineering.

> Must check those PSU electros some day. They were well specced though.