You probably need input from Jim here......I will watch with interest. You
will find the loop calculation in your Terman..............What no Terman!!
call youself an injumier??
:-))
Alan
----- Original Message -----
From: "Andy Talbot" <[email protected]>
To: <[email protected]>
Sent: Thursday, April 01, 2010 2:05 PM
Subject: Re: LF: Re: E-Field Probe calibration question
> Hi Alan + All...
>
> Actually its a bit more complicated on its own... The physical length of
> the element is 0.75m, which is appreciably longer than the electrical
> effective length. And I'm betting a chunk of that difference is made up
by
> having a series resistor in the output circuitry to give a 50 ohm source
> impedance and help stability but reducing voltage gain to below unity. If
> 50R in series, there is an immediate -6dB halving the length. If my
> original dipole concept *were* to apply, then the other half of the leg
> caused by the car would also be affected by the attenuation.
>
> But it appears from your comments so far the argument doesn't apply in
which
> case the 0.15m length still holds. How do the EMC measurement community
do
> it, as their measurements have to be valid in law and could be held up to
> scrutiny?
>
> Now, what was the voltage from an untuned loop, again ;-?
>
> Andy
> www.g4jnt.com
> Mostly retired inguneer
>
>
> On 1 April 2010 12:44, Alan Melia <[email protected]> wrote:
>
> > Hi Andy maybe I dont read it right, but if that is an E-field probe it
is
> > not a "dipole" The input capacitance senses the voltage at two points on
> > the
> > wavefront. The ground plane is, I believe, irrelevant. You just need
> > another
> > capacitance separated from the "probe" to reference to voltage to. See
> > Renato's balanced probe (www.vlf.it) In your case this is the
car.....but
> > it could be the size of a dinky toy.The area of the wavefront
intercepted
> > by
> > the probe or the ground reference does not affect the terminal
> > voltage.....as I see it.................of course I might just be wrong
cos
> > i am really a scientist not an enjuneir!!
> > :-))
> > Alan
> >
>
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