Technical information
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WBT 1968
Depending on the position of the receivers internal antenna, one method may perform better than others.
When is the best time to listen?
Propagation on the AM broadcast band is very similar to 160M. By the calendar, the winter months from
December through February are by far the best as atmospheric noise will be very low. The summer months
with lightning storms and natural atmospheric noise will definitely limit your BCB DX’ing! In general, long
distance reception will be present during periods of darkness and usually exhibit a short time enhancement for
the period beginning about thirty minutes preceding local sunrise and sunset to as much as 30 minutes past
these events. DX’ers often refer to this period as “gray line”. It was during these times when I’ve logged some
of my best catches. During this period, pick a frequency that doesn’t have a dominant station and listen as the
propagation rapidly changes. Often, you’ll hear several stations in the span of 20-30 minutes. If you don’t own
a small cassette recorder, invest in one. Being able to go back and review weak signals is a great help.
So I’ve heard a station but I wasn’t able to get a station ID. Is there any way assist me to identify the
station.
The National Radio Club publishes one of the best AM station directories I’ve seen. Published yearly, it lists all
stations in the U.S. and Canada, sorted by call letters, state, and frequency. In addition, the power, radiation
pattern, station address and format are listed for each station. Often, you can identify a station much easier if
we know the format. Station ID’s are usually given on the hour and every 15 minutes at 15, 30, 45 past the
hour. The NRC log is available from the National Radio Club.
So it would seem that the powerful 50kw stations are easy to hear, but how do you log the rare ones?
In a word, persistence pays off, but there are some tricks! The National Radio club arranges several “DX
Tests” each month. Basically, here’s how they work. The NRC contacts a specific station and arranges for
them to allocate a 15-30 minute broadcast where a unique style of music is played - usually marching music or
polka’s. In addition, the station will identify itself frequently, often using morse code. In doing so, their signal
can be singled out of the noise much easier. It’s also not uncommon for these stations to use omni-directional
radiation patterns that would normally be used only during daylight hours. Stronger stations on the frequency
may also cooperate and go off the air during the DX test. Despite the intense negotiations that must take
place to arrange these DX tests, the NRC usually has 5-10 per month during the BCB DX season that runs
from November through March. While many old timers to this aspect of the hobby regard this as cheating,
most see it no different than making a schedule on the HF bands to work a rare DX station.
Some Closing Comments
During the 1960's and 1970's it was customary for many stations to go off the air late Sunday night into
Monday morning. These were great opportunities to log stations on frequencies that were normally used by
local stations. Improved technology now has solid state transmitters replacing the old tube transmitters. These
new designs are virtually maintenance free and the need to go off the air is no longer there. Also, keep in mind
that air time is very valuable in most metropolitan areas. Being off the air for only 15-30 minutes could result in
the loss of $100,000 or more! In this area we are fortunate
in the respect that most of the NY metro area stations are
in Bergen County area. Many of the chief engineers are
fellow hams and we BCB DX’ers are often informed of
scheduled maintenance that requires a station to leave the
air.
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535 RVC Radio Vision Christiana, Turks &
Caicos
600 WICC Bridgeport, CT
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