Freq. Independent Phase Shifter

[Phil Allison]

"Spehro Pefhany"
"Phil Allison"

"Joke"



0.1% resistors are cheap these days.

** Still about 25 times the cost of 1% MF and of no benefit when the caps
used are only 1% tolerance.

Where can you buy PS caps of any tolerance ?

** LCR Components make polystyrene caps of 1% tolerance & Farnell / Newark
sell them - among others.

http://www.newark.com/lcr-components/mkp-hr-10000pf-1/capacitor-10nf-63v-capacitor-10nf/dp/73K0558

$1.54 each in *one off* cheap enough for you - eh ???

NPO ceramic parts are available, but $$$$.

** Really ???

1% tolerance * silvered mica * caps are available in values like 10nF for
big bucks.


BTW:

What the HELL is the point of your TEDIOUS BLOODY nit picking ????

Got nothing better to do with your life ??



..... Phil

 

[Spehro Pefhany]

"Spehro Pefhany"
"Phil Allison"


** Still about 25 times the cost of 1% MF and of no benefit when the caps
used are only 1% tolerance.

Should improve things by about 30%.

** LCR Components make polystyrene caps of 1% tolerance & Farnell / Newark
sell them - among others.

http://www.newark.com/lcr-components/mkp-hr-10000pf-1/capacitor-10nf-63v-capacitor-10nf/dp/73K0558

$1.54 each in *one off* cheap enough for you - eh ???

Cheap enough. I've heard a lot of complaints about poor availability
of PS caps and PP caps.

** Really ???

Yeah, 18125A103FAT2A AVX 10nF 1% NPO in 1812 form factor, but about
five clams a pop in tens. http://www.avx.com/docs/Catalogs/ccog.pdf

1% tolerance * silvered mica * caps are available in values like 10nF for
big bucks.


BTW:

What the HELL is the point of your TEDIOUS BLOODY nit picking ????

Got nothing better to do with your life ??

Apparently, not at the moment, Phil. How about yourself?

.... Phil

Best regards,
Spehro Pefhany

 

[Phil Allison]

"Spehro Pefhany = PITA Wog Wanker "

"Phil Allison"

Should improve things by about 30%.

** More nit picking hypotheses, not facts.

Yawnnnnnnnnnnnnnn..............

http://www.newark.com/lcr-components/mkp-hr-10000pf-1/capacitor-10nf-63v-capacitor-10nf/dp/73K0558


Cheap enough. I've heard a lot of complaints about poor availability
of PS caps and PP caps.

** You oughta be MORE careful whose bullshit you decide to believe -
pal.

Especially your own putrid variety.

Apparently, not at the moment, Phil.

** You could always do the planet a real favour a top your stupid self.

Maybe just choke to death on your own bullshit.

Plenty of that on hand.



..... Phil

 

[Fred Bartoli]

whit3rd a écrit :

No, it doesn't! Just buffer that output and it's good to go.
It has output impedance variation, not amplitude.

But it does!

That'll get phase shifts from 0 to 90 degrees ("0" shift -> sine, "90"
shift -> cosine).

sin( w*t + phi) = sin(w*t) cos(phi) + cos(w*t) sin(phi)

Pb is that with a pot you're mixing proportionally to the pot angle, not
the sin and cos of the pot angle.

IOW output = phi sin(w*t) + (1-phi) cos(w*t)

(instead of sin(w*t) cos(phi) + cos(w*t) sin(phi) )

which has a min sqrt(1/2) amplitude for phi=0.5

 

[Joe]

[someone wrote] ....
If you are going to a digital approach, programming a cordic would be my
advice. [snip reasons]
Sitting over in Terman is a really great Phd dissertation on the cordic,
better than any book I every read regarding the algorithm. My
recollection is the author's name is Ahmed. Searching Stanford's
Socrates doesn't seem to dig it up though.

Maybe "Signal Processing Algorithms and Architectures",
Hassan Masud Ahmed, PhD thesis, Stanford University, June 1982. (1981?)

It is frequently cited* but might not be freely available online.
*Eg in <http://www.computer.org/portal/web/csdl/doi/10.1109/12.403715> and
<http://www.eecs.berkeley.edu/~newton/Classes/EE290sp99/lectures/ee290aSp996_1/cordic_chap24.pdf>

 

[YD]

Late at night, by candle light, [email protected] (Bill Murphy)
penned this immortal opus:

What about a single card with 4.1 or 5.1 outputs?

Either way, how would I generate the three 120 degree offset channels
in software?

Thank you for your reply.

Try Visual Analyzer from http://www.sillanumsoft.org/ (freeware). It
can generate separate signals in each channel, with phase added. Make
up the third with a handful of opamps and resistors. You can lock the
frequency settings so one adjustment alters both at the same time.

 

[YD]

Late at night, by candle light, Jan Panteltje

Well, if that takes so much time, say more then 2 hours, I think you
need more time to go shopping or order the soundcard thing.
Plus put it in a PC, plus write the soft, plus it is not real time adjustable
with a pot, plus it is not GREEN, it sucks power, plus well it is all so obvious.
Who knows, you may not reach your pension... may as well build it now!

Doesn't take all that much time. The soundcard is usually there
already, d/l'ing the sw is another few minutes (see my above post),
the time to get used to it is about the same as fiddling with a real
generator. Plus the sw comes loaded with a number of other goodies.

- YD.