The Noise Blanker only affects repetitive pulse noise such as ignition
type noise. Lightning and atmospheric is random noise. As to the Noise
Reduction, I find that use of the Attenuation and RF Gain control is far
superior to using DSP systems. Also remember it is Noise Reduction and
not noise elimination as many seem would like to believe. If one
realized 6 dB of noise reduction using the system that's good. At the
same time, any noise reduction system will add distortion to a SSB or CW
signal.
From very authoritative source, the optimum receiver performance
configuration is to have the no signal band noise about 10 dB above the
noise floor of the receiver. Since we can't change the noise floor of
the receiver, the option is to change the incoming level of the noise as
presented to the receiver input. The K3S receiver noise floor is about
-135 dBM. If one has a no signal band noise of S-5 or -97 dBm, the
difference is 38 dB. This says we need 28 dB of Attenuation and RF Gain
reduction. That would be 15 dB of Attenuation and about 2 S units of
RF Gain reduction or 10 dB of Attenuation and about 3 S units of RF Gain
reduction. This in no way changes the sensitivity of the receiver
nor does it impede the ability to hear weak signals. Unfortunately many
hams belie that more gain is needed to hear weak signals. With
receivers of 50+ years ago often the receiver noise exceeded the band
noise. That however is not true with today's modern receivers.
As to using the Noise Reduction, I do not use it at all for SSB and for
CW. If I do use it I find F1 and a value of 1 to 3 about all I'm
willing to accept. Of course the type and magnitude of the noise does
require different settings.
If I use the Noise Blanker I find it necessary to first set the IF NB to
OFF. Then adjust the DSP through its values to get what seems to be the
best result. Remember the value. Then set the DSP NB to OFF. Then to
the IF noise adjustment and find what seems to be the best result.
Leave it at that and then back to the DSP Noise blanker and set it to
the previous obtained value. This optimized them individually. I've
not been successful in trying to adjust both at the same time. And
remember it only works on repetitive noise such as ignition noise or
line noise and not random atmospheric noise.
The receiver gain method works best. Hope this helps.
73
Bob, K4TAX
On 6/13/2019 6:43 AM, Nr4c wrote:
This is not an easy thing.
First, are you hearing general band noise, a constant “ shhhhhhhhhhhh” or
pulses as in lightning, power line, or ignition type noise.
For band noise, the NR will be your best solution. Experiment, but don’t go too
deep. Deep settings will distort and make it sound like you’re underwater.
For the pulse noises, try IF first, again don’t use extreme settings. If this
doesn’t work, try the DSP settings and see if this will work.
I have NB set to Med4. NR is set to F1-3.
YMMV.
Have fun!
Sent from my iPhone
...nr4c. bill
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
