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Re: Terry's New Plane Wave Antenna



Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Dmitry,

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

> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

> 4. For the calibration to be valid, the field distribution needs to
> be the same as for the conditions that are to be measured.

if so, then the next logical question is "on what does the field
distribution depend"?

What I'm thinking here is that as one increases the voltage on the top load, the E field distribution stays linear until something else happens like corona or a streamer. Either one would have the effect of moving the top load voltage closer to the antenna and thus increase the E field at the antenna more that otherwise.

>   Seems
> like calibrating at NST voltages with 60 Hz would work just fine if
> streamers and corona did not happen to distort the e-field from what
> exist at 60 Hz. Not sure about this so please comment.

i`m not sure too, but it appears to me that much stronger fields
(working coil) should have noticeably different configuration than
weaker ones (nst), coz they must interact with surroundings far more.

I too believe that higher voltages result in higher fields that interact with surroundings far more. If, however, the effect remains linear, then things should scale. It is the non linear effects that I worry about.

> What does the low frequency cutoff (10-15Hz) affect??

it affects flat top, but probably i exaggerated this too much - at
least for the transients associated with individual discharges - they
are just too fast for this %-)

I'm not sure what you mean by "flat top". My concern is lingering reflections affecting measurements. If both ends are unterminated then reflections can linger for a "long time" Every transition can initiate a series of reflections so if they dont die quickly, the voltage measured can include a lot of "history".

p.s.
guys - we can theorize endlessly, but don`t you think that _only_ real
way to find an answer at least for the question about validity of nst
calibration (the question number 4) is to ask and wait until Marco
compared results for low/high fields with his resisrive divider?

YES, it is always good to get independent comformation on a result.

Gerry R.