pi phase shift across all frequencies ( 2 Hilb tmers in cascade )
- The only scenario where a non-constant group delay does not
distort your signal ??
shankar
180 degree phase shift
Started by ●July 6, 2003
Reply by ●July 6, 20032003-07-06
On 6 Jul 2003 09:23:49 -0700, kbc32@yahoo.com (kbc) wrote:>pi phase shift across all frequencies ( 2 Hilb tmers in cascade ) >- The only scenario where a non-constant group delay does not >distort your signal ?? > > shankarShankar, what do you expect anyone to say regarding you post? You were too bad-mannered to say "Hello". Didn't your Mother teach you to say Hello to people? In your culture, do people say "Hello", or do they just grunt? Shankar, are you from the planet earth? Your post makes no sense in English. It sounds like a crazy person! Shankar, are you living an a mental hospital now? Do the guards know you have a computer? You didn't have the manners to say "Thanks". In your culture, do people say "Thanks" when they need help? Shankar, were you ever hit in the head with a shovel when you were young? That might explain your behavior now. Why in the name of sweet merciful Jesus in Heaven would you expect anyone to help you? Shankar, if you're working for a company right now, I suggest that you go to your boss and ask him to fire you immediately.
Reply by ●July 7, 20032003-07-07
> > Shankar, > > what do you expect anyone to say regarding you post? > > You were too bad-mannered to say "Hello". > Didn't your Mother teach you to say Hello to people? > In your culture, do people say "Hello", or do they > just grunt? > > Shankar, are you from the planet earth? > > Your post makes no sense in English. It sounds > like a crazy person! Shankar, are you living an a mental > hospital now? Do the guards know you have a computer? > > You didn't have the manners to say "Thanks". > In your culture, do people say "Thanks" when they > need help? > > Shankar, were you ever hit in the head with a shovel > when you were young? > That might explain your behavior now. > Why in the name of sweet merciful Jesus in Heaven would you > expect anyone to help you? > > Shankar, if you're working for a company right now, I > suggest that you go to your boss and ask him to fire you > immediately.My god !!!!! :=) What did I do to deserve that ?? Rick, I would say u have too much free time. :=) shankar
Reply by ●July 7, 20032003-07-07
On 6 Jul 2003 22:58:32 -0700, kbc32@yahoo.com (kbc) wrote:>> >> Shankar, >> >> what do you expect anyone to say regarding you post? >> >> You were too bad-mannered to say "Hello". >> Didn't your Mother teach you to say Hello to people? >> In your culture, do people say "Hello", or do they >> just grunt? >> >> Shankar, are you from the planet earth? >> >> Your post makes no sense in English. It sounds >> like a crazy person! Shankar, are you living an a mental >> hospital now? Do the guards know you have a computer? >> >> You didn't have the manners to say "Thanks". >> In your culture, do people say "Thanks" when they >> need help? >> >> Shankar, were you ever hit in the head with a shovel >> when you were young? >> That might explain your behavior now. >> Why in the name of sweet merciful Jesus in Heaven would you >> expect anyone to help you? >> >> Shankar, if you're working for a company right now, I >> suggest that you go to your boss and ask him to fire you >> immediately. > > >My god !!!!! :=) >What did I do to deserve that ?? > >Rick, I would say u have too much free time. :=) > > shankarHi, ah, I was in a bad mood. I was just ranting and raving about manners. Ya know, the guys in the newsgroup deserve great respect. That's what I was actually trying to say. It's not too much time, it's just old age. [-Rick-]
Reply by ●July 7, 20032003-07-07
Rick Lyons wrote:> > On 6 Jul 2003 22:58:32 -0700, kbc32@yahoo.com (kbc) wrote: > > >> > >> Shankar, > >> > >> what do you expect anyone to say regarding you post? > >> > >> You were too bad-mannered to say "Hello". > >> Didn't your Mother teach you to say Hello to people? > >> In your culture, do people say "Hello", or do they > >> just grunt? > >> > >> Shankar, are you from the planet earth? > >> > >> Your post makes no sense in English. It sounds > >> like a crazy person! Shankar, are you living an a mental > >> hospital now? Do the guards know you have a computer? > >> > >> You didn't have the manners to say "Thanks". > >> In your culture, do people say "Thanks" when they > >> need help? > >> > >> Shankar, were you ever hit in the head with a shovel > >> when you were young? > >> That might explain your behavior now. > >> Why in the name of sweet merciful Jesus in Heaven would you > >> expect anyone to help you? > >> > >> Shankar, if you're working for a company right now, I > >> suggest that you go to your boss and ask him to fire you > >> immediately. > > > > > >My god !!!!! :=) > >What did I do to deserve that ?? > > > >Rick, I would say u have too much free time. :=) > > > > shankar > > Hi, > ah, I was in a bad mood. I was just ranting and raving > about manners. Ya know, the guys in the newsgroup > deserve great respect. That's what I was actually > trying to say. > > It's not too much time, it's just old age. > > [-Rick-]Shankar, You should know that you help put us old farts in bad moods. (I'm older than Rick, but if he thinks the shoe fits, I won't deny him.) Much of what you write comes across as a puzzle. Smart fellows that we are, we usually decipher it and often get it right. Still, I for one appreciate reading "you" instead of "u", "oh oh" instead of "oo", "obesity" instead of "obct" and "asinine" instead of "sn9". The question that set Rick off, "pi phase shift across all frequencies ( 2 Hilb tmers in cascade ) - The only scenario where a non-constant group delay does not distort your signal ??" Is short on grammar and poorly punctuated, but I'll hazard a guess about what you want to know. First off, 180 degree phase shift at all frequencies is merely a matter of sign. Switching the wires to a speaker can produce that shift, so of course it doesn't distort. Second, If I deduce correctly that by "distort", you refer to the shapes of pulses rather than the generation of harmonics, then the property needed to avoid distortion is not linear phase, but constant phase velocity in the band of interest. That is, equal delay of all frequencies. The actual phase of output relative to input is immaterial. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●July 7, 20032003-07-07
On Sun, 6 Jul 2003, kbc wrote:> pi phase shift across all frequencies ( 2 Hilb tmers in cascade ) > - The only scenario where a non-constant group delay does not > distort your signal ??I thought a constant phase shift implies zero group delay. -olli
Reply by ●July 7, 20032003-07-07
Jerry Avins <jya@ieee.org> writes:> You should know that you help put us old farts in bad moods. (I'm older > than Rick, but if he thinks the shoe fits, I won't deny him.) Much of > what you write comes across as a puzzle. Smart fellows that we are, we > usually decipher it and often get it right. Still, I for one appreciate > reading "you" instead of "u", "oh oh" instead of "oo", "obesity" instead > of "obct" and "asinine" instead of "sn9".I mostly agree, except that I was amused when my students started calling the assignments for the course I was teaching (_|_)ignments. Ciao, Peter K. -- Peter J. Kootsookos "Na, na na na na na na, na na na na" - 'Hey Jude', Lennon/McCartney
Reply by ●July 7, 20032003-07-07
On 08 Jul 2003 11:13:59 +1000, p.kootsookos@remove.ieee.org (Peter J. Kootsookos) wrote:>Jerry Avins <jya@ieee.org> writes: > >> You should know that you help put us old farts in bad moods. (I'm older >> than Rick, but if he thinks the shoe fits, I won't deny him.) Much of >> what you write comes across as a puzzle. Smart fellows that we are, we >> usually decipher it and often get it right. Still, I for one appreciate >> reading "you" instead of "u", "oh oh" instead of "oo", "obesity" instead >> of "obct" and "asinine" instead of "sn9". > >I mostly agree, except that I was amused when my students started >calling the assignments for the course I was teaching (_|_)ignments. > >Ciao, > >Peter K. >Hi Dr. K, that's pretty cute (as we say here in the States). I like it. I fully realize that sometimes I behave like a cranky ol' (_|_)hole. See Ya, [-Rick-]
Reply by ●July 8, 20032003-07-08
Actually, I also wish to have a magic wand to make everybody behave as I want them to. :=)> Second, If I deduce correctly that by "distort", you refer > to the shapes > of pulses rather than the generation of harmonics,Hilbert tmer is a linear device and so no harmonics are generated at the output.> needed to avoid distortion is not linear phase, but constant phase > velocity in the band of interest. That is, equal delay of all > frequencies. The actual phase of output relative to input > is immaterial.The statement "linear phase" is equivalent to saying that all tones suffer equal delay. ( A zero-slope line phase plot will distort, unless the value of the const phase is -180 degrees. ) Now , consider the cascade of 2 Hilbert filters, mentioned originally. Input is f(t). Output is -f(t-p). p is the delay. What would be p ? shankar> Jerry-- Direct access to this group with http://web2news.com http://web2news.com/?comp.dsp
Reply by ●July 8, 20032003-07-08
To emphasize, the -180 degree system is not distorting, eventhough each tone suffers a different delay. (Otherwise , u have to interpret multiplication by a negative scalar as "distortion". ) -- Direct access to this group with http://web2news.com http://web2news.com/?comp.dsp
