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LC ladder filter questions

F

Fred Bloggs

Jan 1, 1970
0
Peter said:
I feed my family from "billable hours". Jeesh... my time is valuable, I
don't hang out here
simply to entertain and educate freeloaders!

Especially when they offer only diatribes in return.

HAHAHAHAAAAAAAAAAAAAAAAAAAA....damned money-grubby elitist. Having read
your so-called "expert" explanation several times, it is clearly total
"bullsh_t" boiling down to "it is because it is" type of babble to be
expected from a flim-flam "consultant". You should count your blessings
that the industry is populated by gullible idiots.
 
J

John Miller

Jan 1, 1970
0
Peter said:
Now there's a great question for another thread.

What exactly is the difference between hominy and grits?

Grits are ground dried hominy. These days, because most of us don't have a
grandma who makes hominy at home, the easiest way to experience hominy up
close and personal is to get a can of hominy at the sto'.

Hominy is just corn kernels that have had the hull removed, typically by
soaking in a strong alkali, such as lye. The process makes them swell up,
typically doubling in size (8x in volume). Rinsing/neutralizing thoroughly
is an essential part of the process!

--
John Miller
Hotlanta

"Laugh while you can, monkey-boy."
-Dr. Emilio Lizardo
 
R

Roy McCammon

Jan 1, 1970
0
Tom said:
considered. Indeed that's been the case. Too bad there's not a
trivial way to accomplish the task, but ...

Tom,
If Barlett's bisection method applies, its darn near trivial.

From your statement I have to conclude it wouldn't
work in your case, or else you haven't taken a
good look at the method.
 
J

John Larkin

Jan 1, 1970
0
John:

Even though I was not born in Dixie I consider myself an
adopted Southerner. I have lived in the deep South lo these
many years, and...

Hey I love grits, don't trash grits!


Yeah, right. The next thing you'll be claiming is that you like beer,
too.

John

ps - done any filters for DDS outputs? What with the DAC amplitude
falling off, and the sinc thing, and pushing Nyquist without a lot of
jitter, and having to drive a Schmitt trigger with a healthy whack,
and having to keep it small and cheap, it's an interesting situation.
 
J

John Larkin

Jan 1, 1970
0
HAHAHAHAAAAAAAAAAAAAAAAAAAA....damned money-grubby elitist. Having read
your so-called "expert" explanation several times, it is clearly total
"bullsh_t" boiling down to "it is because it is" type of babble to be
expected from a flim-flam "consultant". You should count your blessings
that the industry is populated by gullible idiots.



And Peter thought *I* was nasty!

John
 
S

Spehro Pefhany

Jan 1, 1970
0
Grits are ground dried hominy. These days, because most of us don't have a
grandma who makes hominy at home, the easiest way to experience hominy up
close and personal is to get a can of hominy at the sto'.

Hominy is just corn kernels that have had the hull removed, typically by
soaking in a strong alkali, such as lye. The process makes them swell up,
typically doubling in size (8x in volume). Rinsing/neutralizing thoroughly
is an essential part of the process!

Here is the description from the The Columbia Encyclopedia, Sixth
Edition.

---
hominy

[Algonquian], hulled corn with the germ removed and served either
ground or whole. The pioneers in North America prepared it by soaking
the kernels in weak wood lye until the hulls floated to the top.
Hominy is boiled until tender and served as a vegetable. Hominy grits
(hominy ground into small grains) are boiled and served as a vegetable
or as a cereal, or they may be shaped into patties and fried; they are
especially popular in the S United States. Samp is a type of coarse
hominy.

corn (in part)

As human food, corn is eaten fresh or ground for meal. It is the basic
starch plant of Central and Andean South America, where it is still
hand ground on metates to be made into tamales, tortillas, and other
staple dishes. In the S United States it is familiar as hominy, mush,
and grits. Starch, sugar, and oil are also extracted for many
products, but the chief use of corn is as animal fodder. It is the
primary feed grain of the United States, where more than half the
annual crop is so used. In Europe this is almost the only use of corn
---

No corn-on-the-cob in Europe? Strange. You can even get it from street
vendors in Asia (often with odd toppings like mayo or chili flakes).
Of course there is a tremendous difference between the coarse cow corn
and sweet peaches-and-cream corn.

Best regards,
Spehro Pefhany
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
No corn-on-the-cob in Europe?

We do have it in UK, but where it's grown I'm not sure. AFAIK, it's not
a common farm crop in UK, although some farmers and market gardeners
grow it. I have also seen it as food for people in places on the
Continent. I remember some very large cobs in a display in Budapest.
 
J

John Larkin

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog


We do have it in UK, but where it's grown I'm not sure. AFAIK, it's not
a common farm crop in UK, although some farmers and market gardeners
grow it. I have also seen it as food for people in places on the
Continent. I remember some very large cobs in a display in Budapest.

Sweet corn is best if you carry a pot of boiling water out to the
plant. Strip the shucks, bend the stalk over until the cob is immersed
in the boiling water, and snap it off.

John
 
D

Don Pearce

Jan 1, 1970
0
Sweet corn is best if you carry a pot of boiling water out to the
plant. Strip the shucks, bend the stalk over until the cob is immersed
in the boiling water, and snap it off.

John

A bit like boiled mutton then? That works best if you put a live sheep
in the boiling water in the field.

d
 
S

Spehro Pefhany

Jan 1, 1970
0
Sweet corn is best if you carry a pot of boiling water out to the
plant. Strip the shucks, bend the stalk over until the cob is immersed
in the boiling water, and snap it off.

John

Ha! That sounds about right. We can usually get it within a couple of
hours of picking, at the right veg. market, in season. Other times of
the year the imported shrink-wrapped product is just a pale imitation
of the real stuff.


Best regards,
Spehro Pefhany
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Don Pearce <[email protected]>
wrote (in said:
A bit like boiled mutton then? That works best if you put a live sheep
in the boiling water in the field.

Boiled mutton is not edible, IMHO.
 
S

Spehro Pefhany

Jan 1, 1970
0
Have you tried it cooked the way I suggest?
d

Remember, the high pitched "screaming" sound is just steam escaping
from their hide. It's really quite humane.

Best regards,
Spehro Pefhany
 
T

Tom Bruhns

Jan 1, 1970
0
Hi Roy (and lurkers),

I have to apologize. You asked a simple, civil question a few days
ago now, and I didn't answer it directly. Please forgive me.

In atonement, I note that you said you could fax me the info about
Bartlett's Bisection Theorem -- and here I offer the lurkers links to
some web sites that explain it quite nicely, no need for a fax:

http://members.tripod.com/michaelgellis/bartlett.html
http://www.electronics-tutorials.com/filters/low-pass-filters.htm
http://my.integritynet.com.au/purdic/lowpass.html

However, as the first of these says right up front, the network you
apply the theorem to must be symmetrical, and in this case, it is
not...not even if you assume the original was a transformation from
equal terminations and get back to the equal terms case. (The filter
I'm working on is an "elliptical-type" one with sixth order numerator
and seventh order denominator. Its zeros, in particular, aren't where
an elliptical filter would have them--the stop-band doesn't have equal
ripple.) Bartlett might get me moderately close, but I'd prefer to
use the numerical methods I've worked on while the postings have
continued, because then I'll have some very handy tools to take care
of a much wider range of filter problems of the sort I run into
occasionally.

Cheers,
Tom

Soapbox comment about some of the more recent postings I've seen in
this thread: When someone makes personal attacks (as opposed to
taking exception to technical inaccuracies) in a newsgroup thread,
they loose credibility in my eyes. I'm sure that's the case with many
of the lurkers trying to learn things, too.
 
T

Terry Given

Jan 1, 1970
0
Peter O. Brackett said:
John:

[snip]
*If* you can get the experts to say more than "No" and "You are daft."

John
[snip]

Jeeeshhhh....

For what you pay for the information on this NG! Be thankful for small
gifts! :)

BTW... if you had to research and cull out all of the information provided
on this particular
thread by yourself you are probably looking at several months of sole effort
work, providing
you don't come to wrong conclusions!

If you attended a *good* school where the professors actually knew and
taught the stuff
you learned on this thread you would likely have paid up to $20,000 and
taken 12 months
to learn it. Of course you would first have to had gone to the effort to
find a *good* school
where the instructors actually know this particular stuff! There aren't
many!

If you hired an expert consultant, say like myself, my one time retainer and
per diem fees
for this kind of information would have cost you at least a couple of
thousand dollars. Of
course first you would have to go to the effort of finding a qualified and
knowledgeable
consultant with an appropriate track record.

And gee... here you got all this "free" information on lossless LC
ladders...

I know that on the Internet, "information wants to be free"!

But do you really have to "trash" the experts who don't really have to read
questions
and post answers?

For example, the only pay back I get from posting to this NG is the
occasional call usually
from a lurker who actually becomes a client and pays for my services.

I feed my family from "billable hours". Jeesh... my time is valuable, I
don't hang out here
simply to entertain and educate freeloaders!

Especially when they offer only diatribes in return.

"Cool your jets" John.

Regards,

--
Peter
Freelance Professional Consultant
Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL.

Peter, I for one would like to offer you my thanks for your lucid, and IMHO
excellent, posts on this subject. I certainly have learned from your posts,
(which I have archived) and have done some research (unnecessary but I like
to be thorough) to confirm your statements regarding LC ladder filter
sensitivity. I have written and tested a variety of digital filters, and the
LC ladder-like structures certainly do work best; I have also just recently
completed a redesign for a client, in which I replaced an infinite-gain BPF
(Q=10) with a negative-K sallen-key BPF. The original design missed the
target centre-frequency by about 15% due to finite GBW, and component
tolerance (GBW variation was the worst) caused tremendous changes in
pass-band gain, rendering the overall circuit inoperable.

I didnt even have to figure out the component sensitivity formulae, as its
all been published before, and a little bit of research showed the original
topology was the worst possible choice.....SPICE Monte-Carlo simulations
confirmed this (in order to model GBW i used a laplace block with a
first-order model, and adjusted Aol and Fo manually - changes in Aol made
very little difference (as expected), but changes in Fo were quite dramatic;
the 1st-order model behaved very like the opamp models, but was easier to
modify).

Correcting the original design for nominal GBW didnt help much, although
using $$ 0.1% discretes tamed the design, except for GBW variations....which
a minimum GBW of 20MHz fixed nicely. In this case cost was the driver, so a
lower sensitivity design (higher pass-band gain, lower Q) allowed me to use
a cheaper opamp, and slightly fewer discretes (1% R, 2% C), yet attain much
better performance (over time, temperature and tolerance - the three "T's" )
than the expensive reworked original design.

It would appear that many "designers" dont take the three T's into account
at all, and are thus blissfully unaware of sensitivity analysis.

cheers
Terry
 
A

Active8

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog


We do have it in UK, but where it's grown I'm not sure. AFAIK, it's not
a common farm crop in UK, although some farmers and market gardeners
grow it. I have also seen it as food for people in places on the
Continent. I remember some very large cobs in a display in Budapest.

Ears, John, unless they actually manage to sell the cobs. The cob is
what's left after you remove the husk, silk, and kernels.
 
A

Active8

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
DOTyou.knowwhat> wrote (in <[email protected]>)
about '[OT] Re: Hominy', on Tue, 13 Apr 2004:

No corn-on-the-cob in Europe?

We do have it in UK, but where it's grown I'm not sure. AFAIK, it's not
a common farm crop in UK, although some farmers and market gardeners
grow it. I have also seen it as food for people in places on the
Continent. I remember some very large cobs in a display in Budapest.

Sweet corn is best if you carry a pot of boiling water out to the
plant. Strip the shucks, bend the stalk over until the cob is immersed
in the boiling water, and snap it off.

John

So I've heard, but I think you let it fully cook while it's on the
stalk, remove, then snap off. Otherwise you'll likely get scalded
snapping it off. But I've seen plenty of corn growing and I think
you'd need to top the plant before sticking the uppermost ear in the
water to make it easier and definitely if you want to keep a fire
under the pot to keep it hot. Alternatly, have a BYOBW barbeque -
Bring Yer Own Boiling Water.

Other things work almost as well like leaving the husk on and
placing it on the grill. You can partially peel it, smear butter in
there and pull the husk back up to keep it from burning. Some people
wrap it in foil while it's still in the husk and throw that on the
grill.

Boiling is obvious, but my stepdad found that 1/4" HOH in a
corningware pan does the job quickly in a nuker. Wet around the lip
of the pan and cover with saran wrap. The wet lip makes the wrap
stick much better.

Lastly, you can steam it. Steam it with your crustaceans and
molusks. What? You don't steam your seafood Maryland style? Your
wrong.
A bit like boiled mutton then? That works best if you put a live sheep
in the boiling water in the field.

d

LOL I love it!

Do they scream like lobsters? :) I'd think that'd give 'em a shot of
adrenaline and make the meat taste like... well, lousy.
 
A

Active8

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
DOTyou.knowwhat> wrote (in <[email protected]>)
about '[OT] Re: Hominy', on Tue, 13 Apr 2004:

No corn-on-the-cob in Europe?

We do have it in UK, but where it's grown I'm not sure. AFAIK, it's not
a common farm crop in UK, although some farmers and market gardeners
grow it. I have also seen it as food for people in places on the
Continent. I remember some very large cobs in a display in Budapest.

Sweet corn is best if you carry a pot of boiling water out to the
plant. Strip the shucks, bend the stalk over until the cob is immersed
in the boiling water, and snap it off.

John

Ha! That sounds about right. We can usually get it within a couple of
hours of picking, at the right veg. market, in season. Other times of
the year the imported shrink-wrapped product is just a pale imitation
of the real stuff.

Best regards,
Spehro Pefhany

Fresh Silver Queen corn rules.
 
J

Jim Thompson

Jan 1, 1970
0
[snip]
So I've heard, but I think you let it fully cook while it's on the
stalk, remove, then snap off. Otherwise you'll likely get scalded
snapping it off. But I've seen plenty of corn growing and I think
you'd need to top the plant before sticking the uppermost ear in the
water to make it easier and definitely if you want to keep a fire
under the pot to keep it hot. Alternatly, have a BYOBW barbeque -
Bring Yer Own Boiling Water.

The Master Chef here (my wife) says "Corn into cold water, bring to a
boil, remove from heat and let stand for about 20 minutes"... makes
*perfect* corn-on-the-cob!
[snip][snip]
Do they scream like lobsters? :) I'd think that'd give 'em a shot of
adrenaline and make the meat taste like... well, lousy.

We get lobsters so fresh and lively here in Arizona that some of them
I have to forcibly hold under until they succumb ;-)

...Jim Thompson
 
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