An Introduction To Propogation
What causes DX to be heard and when should you listen for DX?
Well DX stations usually are heard starting around sunset and ending just
after sunrise. This is because the layer of the ionosphere in which AM
signals are reflected off (or bounce off) of are not ionized or "active" during the
It has been my experience that just around the sunrise and sunset hours have
resulted in some of my better DX catches.
VISIT Steve's SUNSET/SUNRISE SKIP PAGE for more info
about the sunrise/sunset skip phenomenon
This, often times, is because certain
lower powered stations share frequencies with high powered radio stations that use different
antenna patterns during the daytime and night hours.
The lower powered station may be heard at a time when the higher powered station has not
yet changed to it's, or from it's daytime antenna pattern. The hours in which a station
changes it's antenna pattern varies throughout the year based on the sunrise and sunset times.
There may only be a matter of a few days during the winter dx months when it is possible for you to hear
certain stations that would normally be blocked out by a powerhouse station due to earlier sunsets/sunrises.
After a while of listening, you will start to recognize what stations can be heard at what time of the night.
I've noticed that early morning hours will have a higher chance of hearing stations from the west. Also late
afternoon, early evening has resulted in a higher percentage of eastern states.
Auroral activity can greatly affect reception.
VISIT Steve's AURORA DX PAGE and learn
a bit more about how auroras can affect the AM radio band
In Minnesota, it has been my experience that
"local" and "common" stations become blocked out by the auroral disturbance. Not only does this happen,
but signals from South and Southeastern US are enhanced by the aurora.
This allows for prime DX listening conditions. A lot of the commonly heard stations, those you
can hear almost any night you put your radio on, are now not heard. It is an oppotunity to log
new southern stations. I have logged a number of Texas, Louisiana, Georgia, Mississippi, Alabama, Arkansas,
and South Carolina stations during auroras. Also, the West Indies, South, and Central American stations can
be heard during auroras.
Get to know your local area conditions by listening at various times and noting the stations
you're hearing in a logbook as a reference guide to yourself. It will not be long before you
know what stations you hear regularly, these are what I refer to as "common" stations. I know
if I am hearing KRNT in Davenport, Iowa on 1350, chances are there are "normal" or non-aurora conditions.
However if I hear nothing on many frequencies at night, it's likely there is an aurora.