[Top] [All Lists]

Re: [Amps] Amp causing RFI

Subject: Re: [Amps] Amp causing RFI
From: Mark Schoonover <>
Date: Tue, 4 Feb 2020 20:45:21 -0800
List-post: <>
Thanks Jim this is a response I prefer, saying the words you did, being
short with people just doesn't come across very well.

There seems to be a difference between audio techniques, power techniques
and the like but they use nearly the same terminology for
different reasons. I think that leads to some of the confusion going on.

Yes I read the page many times over the years that's why I used it as
an example. I've also read your work too but neither helped with my

73! Mark KA6WKE


On Tue, Feb 4, 2020, 19:44 Jim Brown <> wrote:

> On 2/4/2020 6:07 PM, Mark Schoonover wrote:
> > Straight from the ARRL:
> >
> >
> Did you read that paragraph? AND -- part of it is wrong. It confuses the
> difference between a counterpoise and the earth. The earth is a big
> resistor -- connecting it to the return for an end fed antenna adds that
> resistance to the antenna, burning transmitter power.
> We use radials as a counterpoise -- now, return current flows in low
> resistance copper rather than lossy earth. The current flowing in a
> radial creates a field that couples to the earth underneath it, and the
> loss coupled from the earth shows up as resistance in series with the
> radial. The power dissipated is I squared R, where I is the radial
> current and R is the coupled resistance.
> We can reduce the power lost in the radials by using more radials; as we
> add radials, current divides between them. If, for example, we use 16
> radials, the current in each is divided by 16, and the power lost in
> each radial is divided by 256 (I is squared), so the total power lost is
> reduced by 16. In other words, the lost power falls with the in
> proportion to the number of radials. The EARTH is NOT the RF ground --
> the radials ARE! An excellent analysis in the ARRL Antenna Book shows
> that radials SHIELD the field produced by the antenna from the lossy earth.
> The only case where an earth connection makes an antenna work better is
> for certain types of RECEIVING antennas which work BECAUSE of the lossy
> earth underneath it and a connection to that earth. Loss doesn't matter
> in receiving antennas -- they work by producing a narrow receiving
> pattern by several different mechanisms. They don't make the signal
> louder, but the hear better by rejecting noise.
> > RF grounds do exist. Same page that lists your PDF.
> For many years, I've cringed at least once (and often more than that)
> while reading every issue of QST. Thankfully, it's gotten a bit better
> in the last year or two.
> 73, Jim K9YC
> _______________________________________________
> Amps mailing list
Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>