In article
,
terryS wrote:

For example; the broadcast band (North America) is roughly 550
kilohertz (that's 545 metres wavelength) to about 1.7 megahertz (about
176 metres). That's 3:1 ratio!

HOWEVER, if you will look at the Antenna Design for a AM Broadcast
Receiver, using a Ferrite Loop Antenna, you WILL notice that the
Loop IS Tuned to the specific part of the band that the receiver is
being tuned to, by Linked Ganged Variable Capacitors, in the Receivers
Frontend. These designs have been around for MANY years, (1940's anyway)
and are a very mature technology.