"Telamon" wrote in message
...
In article ,
"David Eduardo" wrote:

Snip

In many markets, 10 kw is not enough to cover the market without being
trashed by manmade noise. Also, the relationship has to considder that
low
band AMs cover much better than high band... a 5 kw on 550 outcovers
vastly
a 50 kw on 1500.

Snip

You are referring to daytime reception only?

Yes. In the US, there are so few stations that have any extended night
coverage as to make the point moot for all but maybe 30 or 40 stations in
the whole nation that can get usable skywave coverage. In any event, night
AM listening is so low that it is irrelevanat, irrespective of coverage.

Considering daytime ground wave propagation, is the difference in
coverage low to high band due to ground conductivity where the high end
of the band has more loss per mile?

Given the same transmitter site, and same radiation efficiency, the
difference is that medium wave signals propagate better watt for watt on the
lower frequencies. Ground conductivity decreases as a function of frequency.
This is why the old adage that 1 kw on 1540 covers better than 50 kw on 1600
is nearly true.