The usefulness of AM broadcast stations depends strongly on where we
live and what we're trying to study.
EU broadcasters use 9 kHz spacing, so looking for carriers from known
stations is probably the key to studying the path from the west coast to
EU. VE6WZ, other Canadian hams, and east coast hams aren't affected
nearly as much by this issue, because their path to EU is off-axis to
much of the US and Canada.
I routinely use daytime AM broadcast signals to check the condition of
my Beverages and VE3DO loops, which are quite vulnerable to damage from
falling branches in my dense redwood forest, which also includes a lot
of smaller trees, like madrone and tan oak. I've developed a spreadsheet
of AM stations within 300 miles of me to facilitate this. My full-wave
Beverages are still providing significant directivity low in the US AM
band.
https://www.fcc.gov/media/radio/am-query makes it easy to develop such a
spreadsheet if we know how to read it. DA means directional antenna, ND
means non-directional antenna, DA-D and DA-N mean directional daytime or
night, and the listings include power levels for daytime and night and
even details of all antenna systems. Stations are licensed for these
parameters to cover their license area while protecting distant stations
from interference, both on their own frequency and on first and second
adjacent channels.
73, Jim K9YC
On 10/12/2026 11:10 AM, Richard (Rick) Karlquist wrote:
The trouble with this concept is that there are hundreds of stations on
any given frequency in locations all over north america, so in general
even if you had propagation from the east coast to W6, the east coast
stations would be lost in the massive QRM of all the other stations
on the west coast. I remember I once heard WCBS on a beverage antenna
going coast to coast, but that probably had a lot more to do with other
stations on 860 kHz being in fades at the time than WCBS suddenly
getting very strong due to propagation.
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