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Re: Terry's New Plane Wave Antenna



Original poster: "Dmitry (father dest)" <dest@xxxxxxxxxxx>

> Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

>>The second case: we use the etched one. Here the ground plane serves
>>to stop the field lines of
>>force at itself, right?

> The etched pattern is to fight eddy currents.  However, since the
> frequencies are pretty low, you could probably use a solid plane just fine.

eddy currents from what - from primary mag field, secondary one,
toroid displacement current? :-)
btw - in what way can eddy currents affect the voltage on C2?

>>And as for the capacitance divider - it has 2 caps:
>>the first one - the capacitance between the toroid and the "sensing" plane,
>>the second - 16nF (that should be choosed for best calibration).
>>You see - we don`t need the ground plane again, coz it doesn`t
>>serves as a capacitor plate for that
>>divider.

> The 16nF is not critical at all.  for the size, that value works out
> well though.

i think that 16nF value is very critical - it (together with 1M input
resistance of the scope) defines lower cutoff frequency. of course if
you use antenna in only non-sparking conditions this makes no problem
to you, but what if you want to see the transients, associated with
the sparks formation?

> The present etch pattern and back plane structure does have advantages at
> very high frequencies, but that may not be an issue at all for most work.

can you be more specific on this one - what exactly adwantages are you
talkin about, except eddy (?) currents? resonances with self
inductance of the flat copper plate? i think this is not a problem
comparing with just bare wire antena (without C2).

-----
Let the bass kick! =:-D