Ron Kenwood wrote:
I have a continuous S7 to S8 noise level at normal SSB bandwidths. If
I had to describe the noise, I would say it sounds like amplified
background band noise. The source is outside my house. Removing the
If the noise is close to gaussian, there is nothing any receiver noise
reduction system can do with it, to actually remove it, although it can
do things like muting the receiver in gaps in the speech, if the speech
is above the noise, or generating a graphic equaliser that de-emphasises
frequency not also being used for the speech.
I have read glowing reports on the effectiveness of the noise blanker,
here and elsewhere. I am wondering if the type of noise is part of the
Noise blankers require that the noise be isolated spikes that can be cut
out without removing too much of the signal.
equation, and I just have a type of noise where the noise blanker is
less effective, or am I doing something wrong, or do I just have
unreasonable expectations?
Knowing the source of the noise might help, as it might give a clue as
to its structure and therefore whether there is anything that can be
done to mitigate it.
My next step will be one of the noise canceling gadgets, if I can't
improve the K3's noise performance.
For gaussian noise, the best option is to eliminate it at source.
Failing that, put it in a null in the antenna pattern will help,
providing the noise has a well defined direction. I assume you are
referring to the sort of noise cancelling device that works by
distorting the antenna pattern.
Note that such devices are not suitable when the antenna is already very
directional, or the sky noise is not significantly greater than the
receiver noise (the device is likely to contribute its own receiver noise).
--
David Woolley
Emails are not formal business letters, whatever businesses may want.
RFC1855 says there should be an address here, but, in a world of spam,
that is no longer good advice, as archive address hiding may not work.
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