I think the common definition of splatter has changed over the years. In the
past, "splatter" meant RF transmitted well outside the intended bandwidth.
In the case of a typical Amateur SSB signal, that would be something beyond
the 3 kHz bandwidth such signals normally occupy. It is usually caused by a
non-linear amplifier in the transmitter - often an external amplifier when
the operator over-drives it in an attempt to get a little more output. 

That is solely a fault of the transmitting station and there's not much you
can do about it at the receiver although the strength of the noise will
diminish as you tune far away.

What often seems to be called splatter today is someone simply trying to
operate too close in frequency to another station so his receive bandwidth
overlaps the bandwidth already being used by the other station. That, too,
can cause splatter-like sounds in the receiver, but it's not the
transmitter's fault. It's the problem of the receiver's operator. You have
to move farther away from the other station's frequency to stop the
interference and to avoid interfering with him. It's easy to check, just
tune in the other station and check his frequency. You should not hear any
interference beyond 3 kHz on the direction of his sideband (that is, tuning
lower in frequency on the 7 MHz band and below or tuning higher in frequency
on the 14 MHz band and above). 

And that's why we carefully follow that common standard for which sideband
to use on various bands. It's quite legal to use either sideband on any band
(at least in the USA), but if people randomly choose sidebands we'd need to
allow at least 6 or 7 kHz between stations to ensure no interference, just
as we do for double sideband A.M. If everyone uses the same sideband, a
separation of 3 or 4 kHz is usually enough (depending upon the quality of
the filters in the receiver). 

Ron AC7AC

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