Radio Preppers

General Category => Antennas => Topic started by: daedalus on November 06, 2019, 11:37:18 pm

Title: antenna theory - fundamentals
Post by: daedalus on November 06, 2019, 11:37:18 pm
After watching the excellent videos on end fed half way antennas on the RadioPreppers youtube channel, I realised I did not have an instinctive i.e. fundamental understanding of how an antenna radiates. After much research, especially in the physics forums, I started to build up a new analogy that I haven't explicitly seen before, its sort of drawn from lots of sources of information.

It is very rudimentary at the moment , I'm starting with visualising a DC pulse along on open wire (the most basic of basics) and aim to build up from there.

The questions I have are :

1) Is this something that might be of interest on this forum
2) Are there any other people who might be interested in collaborating, I really could do with someone to bounce my thoughts off, either on the forum or offline
Title: Re: antenna theory - fundamentals
Post by: gil on November 07, 2019, 06:05:47 am
I'm all ears...
Gil.
Title: Re: antenna theory - fundamentals
Post by: daedalus on November 07, 2019, 06:56:50 am
I will do a youtube video and share the link, it's easier for me to use a whiteboard or pad and sketch it out dynamically. The challenge I am facing is how to show simultaneously time and distance so that it doesn't become a mess of squiggles !

There is one thing holding me back at the moment, how to estimate the electric field lines for a flowing current, there are plenty of static +/- charge diagrams and quite a few which show the "kink" in the field when the charge is accelerating but nothing about an electric field line for a sea of electrons flowing , any thoughts from anyone
Title: Re: antenna theory - fundamentals
Post by: tline on December 16, 2019, 07:17:07 pm
Antennas are like guitar strings.

Antennas radiate magnetic fields like a guitar string vibrates and pushes sound pressure waves away from the length of the string.