PSN-L Email List Message

Subject: Re: Strong Damping Magnets and pick up coil
From: "Geoffrey" gmvoeth@...........
Date: Wed, 4 Mar 2009 11:13:25 -0700

Hello Mr. Green;

I assume VS stands for vertical Short Period.

Id like to put in my 2 cents for your thoughts.

No one as of yet seems to have built what
I consider to be a correct sensor.

You really need a two sensor device that is grounded in
the middle to be a  single three wire device.

This allows to double the signal level as well as provide
a proper balanced input into a differential amplifier.

Both sensors need to be identically matched so it
might be difficult to build.

You cant just make a centered tapped coil.

It needs to be two identical coils arranged in
a series  additive fashion feeding the common center
point and the plus minus signals on a 100%
Shielded Underground cable.

The magnets need to be matched as well in strength.

Just thought Id like to say this since everyone is going
for only a half kinda sensor and not what the input amplifier design
sheets seem to require. ( two identical symmetrical inputs grounded in the center ).
This makes construction more difficult if it is one of a kind.

Cheers :-)

----- Original Message ----- 
From: "Robert O. Green" 
Sent: Wednesday, March 04, 2009 7:45 AM
Subject: Strong Damping Magnets and pick up coil

>I am working on a VS system with Larry's coil, magnet and signal-chain.
> Is there any impact to the pick up coil signal from the strong magnets 
> mounted nearby?
> Rob
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