[AMRadio] AM IARU Region 2 Bandplan
Bernie Doran
qedconsultants at embarqmail.com
Tue Mar 9 06:50:04 EST 2010
reading these comments about bandwidth suggests to me that there are more
than a few the believe under 3 kc bandwidth is fine for AM as it conserves
space. if so why does one even operate AM? why not use only ssb, psk or cw?
better yet do not operate at all, look at the space saved then!!! I thought
most operated AM because they like the quality of the audio produced. one
thing the SDR-Iq that I acquired a few months ago does rather well is show
the spectrum, on the local BC stations they seem to limit sharply at a
total 15 kc. I have watched the male voice spectrum and with the exception
of the S,F and C sounds nearly all is below 5 kc each side. narrowing to 3
kc with below 300 cutoff turns those same voices into something that is not
really pleasant to listen too. I have noticed the same effect on a few that
are trying AM with a rice box that uses only 300 to about 3kc. the same
thing can be observed with the ESSB guys on the bottom of 80, they sound
much better, but still a little strange.
again, this is good reason to operate down low on 80 where there is usually
plenty of room. if there are contests it might be best to simply avoid
operating, not only to give the contesters a band, but to simply avoid the
QRM created by others. However, there is so much racket no one would
notice if an AM station was 30 kc wide during the contests.
RE the comments about power, the antenna is far above every thing else,
listen to what the strong stations are using, rarely does an out of the box
multiband antenna come in at the top of the heap. Dipole, open wire feeders
from a good antenna matching device (balanced link coupled) is the simplest
way to go with a multiband operation. The always perform well. the
comments about " use only the " necessary power and/or bandwidth" I believe
that to mean full quieting and the audio quality of a person sitting the
same room with me. It does not mean if I am on a particular freq for an hour
or so and someone decided to operate 1.5 kc away that it is my fault for
causing QRM to them. some of these comments sound similar to those I have
seen where it is believed that we are supposed to be on certain freq (
channels) . At least there has been a lot of chatter on this topic. that
is good. 73 Bernie
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