I agree that wider spacing between SSB signals is generally better. And
5 kHz spacing is plenty. When the band gets busy, either from lots of
activity, or from SW BC stations in the case of 40 meters, it may become
necessary to get a little closer. With most good SSB rigs 3.0 kHz
spacing will still be plenty. Unless one of the signals you are having
to get close to is very strong or very broad, 3.0 kHz spacing will be
just as good as 5 kHz. When it gets even more crowded, we can squeeze
even closer and 2 kHz spacing will be usable. This is especially true if
we use 1.8 kHz filters (in the 6.3 MHz IF on an Omni) and adjust our PBT
carefully. The adjustment of the PBT may need to be changed for
listening to different operators on the same frequency, due to their
voice characteristics. If one of the adjacent signals is using 2.8 kHz
filter in their transmit IF, instead of 2.4 kHz, that station will be
making it more difficult than it has to be, for the sake of hi-fi audio,
even though the other stations in QSO with him are likely using their
narrower filters and not hearing all of his extra wide signal.
The above is oversimplified, in that it says nothing about the steepness
of filter skirts. Nevertheless the principals are valid. I still
maintain that QSO spacing is a dynamic process, and skilled operators
adjust to fit the conditions. The use of wider filters in the
transmitter make the situation more difficult when the band gets crowded.
On the other hand, with CW more signals closer in just makes for a
greater sense of community, instead of an annoyance. As long as they are
not too close or too strong, I like hearing other CW QSOs in my receiver
passband. My psycoaccoustic signal processing deals with them nicely.
DE N6KB
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