On Thu, 12 Oct 2017 04:32:03 -0700 (PDT), "
wrote:

And, one of these will truly separate fly-poop from pepper.
Give it an 80' longwire and you will be getting AM from
Hawaii - or thereabouts.

Yeah, that's the conventional wisdom. I have a different view.
A bigger broadband antenna does not produce a better AM signal.
What happens when you install a bigger antenna is that you
simultaneously increase the signal and the noise pickup with the SNR
(signal to noise ratio) being constant. At BCB (broadcast band)
frequencies, the atmospheric and man made noise is quite high.
https://upload.wikimedia.org/wikipedia/commons/9/93/Atmosphericnoise.PNG
Hearing a distant station with good fidelity and low noise is not so
much a matter of having a strong signal, but more a matter of reducing
the noise. The noise can be switching power supplies, motors,
appliances, and mixing between two or more out of band stations.

The antenna does not need to be huge. See various version of the
PA0RDT mini-whip antenna for clues on what can be done with very small
antennas:
http://dl1dbc.net/SAQ/miniwhip.html
https://www.ebay.com/sch/Ham-Amateur-Radio-Antennas/4672/i.html?_nkw=mini+whip+antenna
https://www.google.com/search?q=pa0rdt+mini+whip&tbm=isch

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558