Re: NOT the feedline

Posted by Bob McGraw - K4TAX on Jun 02, 2020; 3:50pm
URL: http://elecraft.85.s1.nabble.com/Re-NOT-the-feedline-was-KPA-1500-faulting-on-6m-SWR-issues-tp7661502p7661580.html

It is correct that there is no such thing as a breakdown voltage, as
stated earlier. This becomes obvious since the units are given as V/m,
which is represents Volts per meter, or Electric Field strength.

Also, unless one is measuring the field in between two plane parallel
metallic plates, the Electric Field will, in general, not be uniform,
I.e., the field strength (the amount of "pull" on an electron), will
vary with position. This shape does matter, and sharply pointed emitters
can cause breakdown at values considerably less than the maximum
measured in a uniform field.

The Volts/meter relationship is also pressure-dependent, and this
relationship goes nonlinear at low pressures (not enough charge
carriers) following Paschen's law
<https://en.wikipedia.org/wiki/Paschen%27s_law>. It also varies with
humidity and other contaminants, which usually increase arcing.

73

Bob, K4TAX


On 6/2/2020 8:54 AM, [hidden email] wrote:

>
> The RMS voltage for 1000 watts into a perfect load is <250 volts. I
> suspect that Tony's 4,000 voltage limit is closer to what a quality
> PL-259 can actually handle. If the PL-259 is arcing, there is
> something very wrong with either the connector, the weatherproofing or
> the antenna.
>
> John KK9A
>
>
>
>

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