[sdiy] Handy DIY tip #213/noise color

[patchell]

    That is actually no small feat...one of the first things I designed, after
getting out of college, was to design a low noise amplifier for testing infared
sensors.  To test the amplifier, I used a 10 ohm, wire wound resistor.  I can't
remember how close I got, but I seem to remember that the amplifier contributed
something like 10% of the noise...it was pretty dang quiet...the design was all
descrete...there were no quiet op-amps back in those days...

Tim Ressel wrote:

> Tim, (great name by the way)
>
> Yep, indeed. I remember an opamp datasheet that
> bragged about the opamp's noise was lower than that of
> a 50 ohm resistor.
>
> --tr
>
> --- Tim Parkhurst <tparkhurst at siliconbandwidth.com>
> wrote:
> > > -----Original Message-----
> > > From: Edu Silva [mailto:bahi0387 at terra.com.br]
> > > Sent: Tuesday, January 14, 2003 2:53 AM
> > > To: synth-diy at dropmix.xs4all.nl
> > > Subject: Re: [sdiy] Handy DIY tip #213
> > >
> > > Ken Stone wrote:
> > > >
> > > > And make sure you use metal film resistors too.
> > :)
> > > >
> > >
> > > The blue ones, and you will get "blue noise"!!
> > :-)
> > >
> > >
> > > Edu Silva
> > > http://audiolist.cjb.net
> > >
> >
> > An EE friend of mine told me once you actually could
> > make a noise source by
> > simply using a long string of resistors. A bunch of
> > carbon film units, and
> > then amplify the signal and you're all set. They
> > apparently generate a small
> > amount of "thermal noise" but you'd need over 100
> > resistors to get something
> > even worth amplifying. I think a crappy (hand
> > selected to be crappy, of
> > course) zeener is a much easier method. ;)
> >
> > Tim Servo (furiously searching for red, white and
> > blue resistors for his
> > tunable and very patriotic noise source)
> >
> > "Imagination is more important than knowledge." -
> > Albert Einstein
> >
> >
> >
> >
> >
> ***************************************************************************
> > This message is confidential.  The information
> > contained in
> > this e-mail message is intended only for
> > confidential use of the
> > recipient(s) named above. If the reader of this
> > message is not the intended
> > recipient or an agent responsible for delivering it
> > to the intended
> > recipient, you are hereby notified that you have
> > received this document in
> > error and that any review, dissemination,
> > distribution, or copying of this
> > message is strictly prohibited.  If you have
> > received this communication in
> > error, please notify us immediately by e-mail, and
> > delete the original
> > message.
> >
> ***************************************************************************
> >
> >
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> http://mailplus.yahoo.com

--
 -Jim
------------------------------------------------
* Visit:http://www.silcom.com/~patchell/
*-----------------------------------------------
*I'm sure glad Merry Christmas comes just once a year
* -Yogi Yorgensen
------------------------------------------------