Re: LF: tribute at Claude Shannon

[Andy Talbot <andy.g4jnt@gmail.com>]

Strictly, Shannon was a mathematician who approached information theory from a non engineering perspective.   And the famous Shannon curve giving the absolute theoretical limit of performance for a communications channel was, I believed, developed by trying to pack spheres into a volume - or some equally non-related piece of ephemera.

Occasionally it needs someone with no background in the engineering side of things to develop a basic theory that sets a limit or reality check on what the specialists in an area are trying.

Another case like this is the Chu limit relating Q, size and efficiency of antenna (or bandwidth, size and loss, or some other set of three similar parameters).   This Chu, or Chu-Harrington limit (Google it)  shows why small magnetic loop antennas are narrow band, or lossy, or both.   The equation was developed purely mathematically, with no reference to real antennas at all and defines a lint to what can be done with real ones

Andy  G4JNT

On 30 April 2016 at 10:13, IZ7SLZ <iz7slz.domenico@gmail.com> wrote:

Hi EbNauters,

Google.it  today's logo reminds the 100th anniversary of Claude Shannon birthday:

https://www.google.it/logos/doodles/2016/claude-shannons-100th-birthday-5731852344098816.3-hp.gif

I'm following with many interest the EbNaut VLF experiments from DK7FC, DF6NM, Paul Nicholson and others and i want to say a big thank-you to all people involved (including DL4YHF, DJ8WX,..) for sharing their works, opinions and results.

And,  of course, a big thanks to Scientist like Shannon for their valuable "opera" (from Latin)  that have given us the theoric bases for our "games".

A good week end to all.

73, Domenico iz7slz