Odp: [sdiy] sniffing

[Roman Sowa]

the ground would be you, holding the probe.
For E-field measurement, you need 2 poles at different
locations, one being a plate or ball, the other - user
holding it, connected to meter's ground via stray resistance.

As H-field detector I used once 12000 wounds coil
from old synchronous motor. It was good enough
to find live cables in the wall, just what I needed.

But for things like radios, and other transmitters being
far away (multiple wavelenght at least) it doesn't matter
IMHO if you measure E or H, as they are closely combined
by wave-impedance of the medium (air)
Am I mistaken?

Roman

----- Original Message -----
From: Czech Martin <Martin.Czech at Micronas.com>
To: Magnus Danielson <cfmd at swipnet.se>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, April 15, 2003 10:06 AM
Subject: [sdiy] sniffing


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