Everything is important when you deal with noise.
Maybe there is something not considered before.
I'M always looking for new data as it relates to noise
and signal to noise ratio improvement.
This subject is of interest to myself as well as the initiator
of the thread.
Have you ever thought about the microphonic oscillator  ?
Residing within each and every household item of an electronic
nature.
Its not meant to modulate anything directly yet can send your voice
all over the world.
I understand it really does make a signal to noise
improvement to use a larger mass on your sensor.


----- Original Message ----- 
From: "GPayton" 
To: 
Sent: Friday, May 14, 2010 10:10 AM
Subject: Re: Electronic noise


> Good information and suggestions.  However, I don't believe that Jon
> mentioned the SOURCE of his interference or the DISTANCE of his needed run.
> Both are important factors to consider.
> Regards,
> Jerry
>
>  ----- Original Message ----- 
>  From: Geoffrey
>  To: psn-l@..............
>  Sent: Friday, May 14, 2010 12:02 PM
>  Subject: Re: Electronic noise
>
>
>  At the local hardware store ACE BEST or whatever
>  I found a signal cable suitable for underground buriel
>  which has some kind of grease impregnated beween the shield
>  and the cable jacket to keep moisure out.
>  I installed a 40 foot run of it several years ago
>  and it still seems good. The shield is heavy copper foil
>  which makes the cable not as flexable as it might be with
>  a braided shield. You just need to shield the jacket from sunlight
>  everywhere it might be above ground.
>
>  Also you should avoid what is called ground loops
>  which can indice unwanted noise inside the cable
>  this can be avoided by choosing your gound
>  and making sure the shield is broken at one side of the connection
>  or another to eliminate a DC path. I will typically
>  break the shield on the side opposite of the
>  side chosen as the primary ground.
>
>  DC/LOW FREQUENCIES will travel deep within a conductor.
>  But like over 1 MHZ the current exhibits a skin effect
>  and only travels like within the first 1/8 inch of the surface
>  with that skin getting smaller/thinner as the frequency increases.
>
>  I shoiuld imagine the impedance is also related to this skin effect.
>
>  It seems to play a role in antenna design visible as gamma matching.
>
>  Coaxial cable would be quite suitable for low frequencies
>  if 100% shielded and have a proper BALUNS to keep
>  RF out of the inside of the cable.
>  A BALUNS may be as simple as a series of
>  FERRITE beads at  the open ends of the shield.
>  The broader the frequency block the more
>  beads you need and they are not cheap.
>  They come in sizes for one wire or a whole 1/4 inch cable
>  as a split bead. I have seen them at Radsio Shack
>  in the past.
>  You want to make sure what flows on the outside of a coax
>  does not leak into the inside. And, Vice Versa.
>
>
>  ----- Original Message ----- 
>  From: "GPayton" 
>  To: 
>  Sent: Wednesday, May 12, 2010 5:16 PM
>  Subject: Re: Electronic noise
>
>
>  > Jon, in the past I have observed that RCA type (audio) cable may not
> have
>  > complete shielding; some ever have had a small thread of wires and
> called it
>  > shielded.
>  >
>  > You might try coaxial cable.
>  >
>  > Regards,
>  > Jerry
>  >
>  >  ----- Original Message ----- 
>  >  From: Jón Frímann
>  >  To: PSN-Postlist
>  >  Sent: Wednesday, May 12, 2010 7:09 PM
>  >  Subject: Electronic noise
>  >
>  >
>  >  Hi all,
>  >
>  >  I did replace my cable the other day from Cat-5 shielded cable to a RCA
>  >  cable that is also shielded. But with the Cat-5 cable I did not get
>  >  electronic noise. But with the RCA cable I do. I rather do not want to
>  >  switch back to the Cat-5 cable, as it is harder to manage.
>  >
>  >  What might be the reason why I am seeing electronic noise on the RCA
>  >  cable ?
>  >
>  >  Regards,
>  >  -- 
>  >  Jón Frímann Jónsson
>  >
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