[sdiy] Re: sniffing

[Magnus Danielson]

From: "Czech Martin" <Martin.Czech at Micronas.com>
Subject: sniffing
Date: Tue, 15 Apr 2003 10:06:55 +0200

Hi Martin,

> As a magnetic field probe I just used a roll of isolated wire (cord),
> about 20 loops. In the way this wire is sold, I had simply to cnnect the ends.
> 
> Perhaps for higher frequencies only one loop would be better.

Yes. A pretty good start you get by taking a coax cable and strip the shield of
the last 5 cm of the unconnected tail. Bend the center-conductor into a circle
and connect it to the shield.

> But how can you build a low cost E field probe?

Take another coax cable. Strip 3-4 cm of shield of it and you have yourself a
little dipole antenna.

> Perhaps an aluminum ball? Where goes ground in this case?
> Or two balls forming a dipole?
> Perhaps a jfet could be used to buffer the high impedance in this case?

You want an amplifier regardless.

Cheers,
Magnus