Subject: Re: [FG]: Gradiometer

From: [email-masked]
Date: Sat, 1 Jan 2005 14:23:59 EST

Thanks. I disconnected the antenna off of the "emitter" and it still responds 
to the static built up from combing my hair. I experimented with a 1m ohm 
resistor and a 100 ohm resistor and it seems the 3k resistor responds best. 
Should I leave the resistor? I tried twisting the gimmick tighter and even loosing 
it but it didn't seem to do anything that I could tell. Thanks again for the 
help. Never really worked with a circuit as quirky as this!  I'll check out RS 
to see if they carry the book you refer to.

In a message dated 12/31/2004 10:46:46 PM US Mountain Standard Time, 
[email-masked] writes:
Hi,

The low value resistor gives you solid DC control of pin #3, but 
probably you have lost any sensitivity in the "emitter" antenna. Try 
removing that antenna and see if the circuit still responds to hair 
combing as before. You could try twisting the "gimmick" tighter or 
looser instead of trimming it shorter. When you change the "bias" 
control, you get near-instant change of voltage in Pin #3 circuit, but 
the voltage changes on pin #2 have to "leak" through the "gimmick" to or 
from pin #1. The only time that pin #1 sits at 0 volts is when the 
voltages on pins #2, 3 are equal to each other. RS used to have small 
booklets that gave basic skills with op-amps.

Have a good one, Keith

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From: "Keith E. Millard" <[email-masked]>
Date: Sat, 01 Jan 2005 13:49:47 -0800

Hi,

The resistor seems to be making the circuit usable, so stay with it for 
now. You might try smaller increments of resistance--6.8K, 10K, etc., to 
see if you are proceeding in the right direction. This thing is almost 
in the realm of magic--maybe a few special words are required.

If RS doesn't have any books, maybe your local library has a copy of  
"IC Op-Amp Cookbook" by Walter G. Jung. This one goes back a few 
decades, but is well written and understandable.

Keith

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From: urx <[email-masked]>
Date: Sun, 02 Jan 2005 15:19:16 +0200

Hello all,
i am not sure is it right place to post this question, but i'm 
interested to develop system what can register signals like we do with 
dowsing. The result could be seective pc-based radar to analyse any 
object in world. The main problem is do we need send out some signal or 
human body just selecting some kind signals(patterns) and by this knows 
where the object is located.
Any ideas or suggestions?

regards,
urx.