RadioBanter - View Single Post - improve S/N for AM car radio by a factor of 2...5...10?

Richard Clark · January 24th 09, 01:00 AM posted to rec.radio.amateur.antenna

On Fri, 23 Jan 2009 17:06:24 -0600, (Richard
Harrison) wrote:

Jim Kelley, AC6XG wrote:
"Scientists at the MIT Radiation Labs during World War ll found that it
was a simple matter to measure E and H individually."

Yes indeed. Two dircuits in separate shielded enclosures can be coupled
with a coupling capacitor and only the E-field gets through. Similarly,
two transformer windings separated by a Faraday shield are completely
coupled magnetically and have no electrostatic coupling. I`ve worked in
several broadcast stations and all towers were so coupled to avoid
capacitive coupling which could give advantage to harmonic frequencies
over the broadcast fundamental frequency.

Yes indeed. Two examples of rare species that require a controlled
environment to persist.

However, neither describe how you can build an antenna that can boost
its S/N ratio by virtue of ignoring one field over the other - unless
Art has a 160M (AM Band much less) waveguide invention that occupies
the volume of a container of Quaker Oats.

Let's for the moment squeeze our eyes real tight and imagine that it
has come to pass and here comes the noise and the signal (of that
eponymous S/N ratio fame). They both impinge upon this "state of the
Art" design. Which field is chosen won't matter much (but I can
imagine this will be argued until the design is deaf to both).

73's
Richard Clark, KB7QHC