Wind/Solar Electrics ???

Where is the baseband information stored if it isn't
encoded into the sampling?

"Hal Murray" wrote in message
...
So, if I have a signal with a 1000 hz carrier, with
a bandwidth of 50 hz,
you think I can sample it at just 150 hz and get
accurate reproduction?
That's just wrong.

No, that's the whole point of this discussion.

You have to understand aliasing. The signal you want
aliases
down into the baseband. Your anti-aliaising filter
has
to get rid of all the junk you don't want. In this
case it
includes the baseband. Since there is no baseband
signal
(or other out-of-band junk) you can reconstruct the
original
signal.

It's a common trick with software radios.

You do need some extra information that doesn't go in
through
the A/D channel. That's the design of the system, in
particular
what the anti-aliasing filter lets through.

Maybe the reason that this is so confusing is that
you also need
that info the the normal/baseband case. But since
that's the normal
case we don't bother mentioning it.

--
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other mailboxes. Please do not send unsolicited bulk
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commercial e-mail to my suespammers.org address or
any of my other addresses.
These are my opinions, not necessarily my employer's.
I hate spam.

Where is the baseband information stored if it isn't
encoded into the sampling?

I'm not sure what you are asking.

If you have a 1 MHz carrier with 1 KHz of bandwidth,
you might do something like sample at 10 KHz so
your anti-alias filter has some room to work with.
Then you feed the signal into a FFT and throw away
the buckets that the filter didn't get rid of.

You often pick the sampling frequency so the FFT buckets
(after aliasing) come out on convenient numbers.

If by "baseband" you mean the raw signal between 0 and X,
there isn't any information between 0 and X-tiny in a typical
narrow band modulated signal.

If you are doing the aliasing trick, the anti-aliasing filter
has to block the baseband junk (noise) or it will get into the
A/D and confuse things. It's the reverse of the "normal" anti-alias
filter that gets rid of the noise above the baseband so it doesn't
alias down and trash your signal.

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

George is alive and well and full of Christmas cheer.

Merry Christmas to all and may you all have a great solar new year.

Even you Wayne.

wmbjk wrote:
On Sun, 25 Dec 2005 17:50:50 +1100, George Ghio
wrote:


"George Ghio" wrote in message
...


Yes this is the problem. While there are people who will tell you anything
to make a sale, how do you know what you are really getting.

One test is the "Modified Square Wave" test.

When you hear these words you know you are dealing either with a shyster
or an ignorant person who should not be selling things he does not
understand.


daestrom wrote:

Judging from your previous posts, I think you mean when you hear "Modified
*sine* wave", then you know you are dealing with shyster or an ignorant
person...."

A salesperson that says their unit puts out a modified *square* wave would
be a sign[sic] of a knowledgable salesperson.

daestrom


I'll pay that. Thank you for the correction. Spent too many hours under
the car, I guess.


OHMYGOD! A blunder admitted! Who the hell are you and what have you
done with George Ghio?

Wayne

PS It's in everyone's best interest that you not be found out, so
don't forget to hide your pod.

You too George.

Merry Christmas to Wayne and all his socks.

"George Ghio" wrote in message
...
George is alive and well and full of Christmas cheer.

Merry Christmas to all and may you all have a great
solar new year.

Even you Wayne.

wmbjk wrote:
On Sun, 25 Dec 2005 17:50:50 +1100, George Ghio

wrote:


"George Ghio" wrote in
message
...


Yes this is the problem. While there are people
who will tell you anything
to make a sale, how do you know what you are
really getting.

One test is the "Modified Square Wave" test.

When you hear these words you know you are
dealing either with a shyster
or an ignorant person who should not be selling
things he does not
understand.


daestrom wrote:

Judging from your previous posts, I think you mean
when you hear "Modified
*sine* wave", then you know you are dealing with
shyster or an ignorant
person...."

A salesperson that says their unit puts out a
modified *square* wave would
be a sign[sic] of a knowledgable salesperson.

daestrom


I'll pay that. Thank you for the correction. Spent
too many hours under
the car, I guess.


OHMYGOD! A blunder admitted! Who the hell are you
and what have you
done with George Ghio?

Wayne

PS It's in everyone's best interest that you not
be found out, so
don't forget to hide your pod.

The point is the sampling rate has to be done at just
over double the frequency of the signal and not the
bandwidth.

"Hal Murray" wrote in message
...
Where is the baseband information stored if it isn't
encoded into the sampling?

I'm not sure what you are asking.

If you have a 1 MHz carrier with 1 KHz of bandwidth,
you might do something like sample at 10 KHz so
your anti-alias filter has some room to work with.
Then you feed the signal into a FFT and throw away
the buckets that the filter didn't get rid of.

You often pick the sampling frequency so the FFT
buckets
(after aliasing) come out on convenient numbers.

If by "baseband" you mean the raw signal between 0
and X,
there isn't any information between 0 and X-tiny in a
typical
narrow band modulated signal.

If you are doing the aliasing trick, the
anti-aliasing filter
has to block the baseband junk (noise) or it will get
into the
A/D and confuse things. It's the reverse of the
"normal" anti-alias
filter that gets rid of the noise above the baseband
so it doesn't
alias down and trash your signal.

--
The suespammers.org mail server is located in
California. So are all my
other mailboxes. Please do not send unsolicited bulk
e-mail or unsolicited
commercial e-mail to my suespammers.org address or
any of my other addresses.
These are my opinions, not necessarily my employer's.
I hate spam.

The point is the sampling rate has to be done at just
over double the frequency of the signal and not the
bandwidth.

I'm sorry that I'm not smart enough to describe it in a way
that you can understand.

Maybe if you google for software-radio you will find something
that explains it in a way that makes sense.

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

On Sun, 25 Dec 2005 17:50:50 +1100, George Ghio wrote:

On Sun, 25 Dec 2005 17:50:50 +1100, George Ghio top-posted:

I'll pay that. Thank you for the correction. Spent too many hours under
the car, I guess.


Just out of curiosity, is top-posting de rigeur on the
rec.ovulation.awning NG? Someone has crossposted this to sci.erectionics.
desire, and the convention there is to bottom- or mid- (or interspersed- )
post.

Just wondering - the clsoest I've been to aviating is I logged 4 hrs.
worth of lessons in a C-150, and onec I sat in the Republic Airlines
DC-9 simulator - that was a trip! My only other associations with
aircarft other than as a passenter is that I worked at a place that sold
little tiiny 28V 40A PSUs, and I'd rather jump out of an airplane (with
a proper aprachute, of course), than try to land one. ;-)

Thanks!
Rich


daestrom wrote:
"George Ghio" wrote in message
...

Yes this is the problem. While there are people who will tell you anything
to make a sale, how do you know what you are really getting.

One test is the "Modified Square Wave" test.

When you hear these words you know you are dealing either with a shyster
or an ignorant person who should not be selling things he does not
understand.



Judging from your previous posts, I think you mean when you hear "Modified
*sine* wave", then you know you are dealing with shyster or an ignorant
person...."

A salesperson that says their unit puts out a modified *square* wave would
be a sign[sic] of a knowledgable salesperson.

daestrom

Which one do you have trouble reading?

"Rich Grise, but drunk" wrote in
message
news
Just out of curiosity, is top-posting de rigeur on
the
rec.ovulation.awning NG? Someone has crossposted this
to sci.erectionics.
desire, and the convention there is to bottom- or
mid- (or interspersed- )
post.

George Ghio wrote:
wrote:
George Ghio wrote:

I did build a kit inverter, once, years ago. It had a max rating of
150W, Which it met.

It had a half hour rating of 0W

And a surge of about 300W

I'm still scratching my head over that one.

Which part don't you understand

I didnt seriously think you were going to stand by the above specs.
Since you are, enough said.


NT

wmbjk wrote:
On 23 Dec 2005 23:57:27 -0800, wrote:

George Ghio wrote:

I did build a kit inverter, once, years ago. It had a max rating of
150W, Which it met.

It had a half hour rating of 0W

And a surge of about 300W

I'm still scratching my head over that one.


NT

He previously wrote about using either a 150 Ohm rheostat (other times
referred to as 150A or 200A), or 300k nichrome wire to control a few
Amps of field current on a small 12V automotive alternator. According
to the "designer" (who often refers to himself as a "solar power
consultant"), 150 Ohms didn't allow sufficiently low output, hence the
need for the nichrome wire. And as we all know, the prime
consideration on a home-power generator is low output. snorf Similar
wisdom surely underpins his other projects. For instance, liberal
application of 300k wire might be useful when building a max 150, peak
300, zero Watt inverter, or most any zero Watt inverter for that
matter. Perhaps strung around the property in large coils like razor
wire at Slinky Manor. ;-)

Wayne

The trouble is he may actually BE a solar consultant. Nothing
stopping him afaik. At least not for a few years anyway.


NT