On Nov 3, 10:42 am, David wrote:
On Sat, 03 Nov 2007 01:07:35 -0700, RHF
wrote:

- - the whip

This is basically what's happening with a rod antenna:

http://www.uoguelph.ca/~antoon/circ/activant.html

David,

Yes many 'portable' AM/FM Shortwave Radios do incorporate
a DX Switch {RF Pre-Amplifier} which effectively makes their
built-in Whip Antennas an Active Antenna.

The Grundig Satellit 800-M and Eton E1 Radios come to mind.

~ RHF