[AMRadio] [CW] Elimination of CW-Only Sub-bands


Rob Atkinson ranchorobbo at gmail.com
Wed May 18 06:09:56 EDT 2016


>While 8.0 KHz may seem to many to be a reasonable maximum bandwidth for the
>usual AM signal, there is no compelling reason at this time to suddenly
>impose specific, enumerated limits to AM or any other mode, especially
>considering that band congestion has fallen off in recent years compared to
>what we have endured in the past.  This proposal would make no distinction
>between the bandwidths of double-sideband AM and that of single-sideband;
>they would both be limited to 8 kHz maximum.

In addition, I understand the petition specified the 8 kc limit at the
-20 dB points.  I and I am sure others, do not know exactly how that
translates to practical bandwidth, especially with a vintage rig.  The
petitioner is evidently not an operator of many of the modes he seeks
to regulate, for if he were, at least for AM, he'd be aware of this
difficulty.   I want to not focus on the nerve of a relatively new ham
trying to force his radio world-view on the rest of us, and instead
address the problem of X kc at -Y dB.   The past bandwidth attempt put
the occupied bandwidth at -6 dB, which is similar to IF filter
specifications and I think is more of a standard.  I don't know how
that translates to -20 dB and I guess it depends on the particular
transmitter as to its practical bandwidth for received audio (assuming
a receiver with the necessary passband), so measurement ability is
needed by each operator,  I lack that capability and I have no
intention of buying a computer spectrum display rig to perform it just
for this one requirement.  Perhaps the petitioner assumes everyone
runs a plastic radio and this is not an issue.

In any event, it is a moot point because as Don stated, any numerical
bandwidth limit rule is amateur radio re-regulation which is simply
not needed.

Rob
K5UJ


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