hi all

I have a question in my mind:

how it was radio frequency spectrum Past and Present( is mean now )?

how it was antennas Past and Present(is mean now )?

 

Hello,

Have a look at some very old books that you can download here:
http://www.tubebooks.org/technical_books_online.htm

Then compare them with new books you might find in the library.

Bertus

 

please Join me your ideas about radio frequency spectrum and antennas at old and now