[Elecraft] [K3] Noise Blanking, all-mode squelch- any strategies for settings?

[K8JHR]

Hi Arlen  -  I, too, seek just such a general guide for using the 
various noise reduction features on modern transceivers, but have yet to 
find one.  Transceiver user manuals are typically pretty lean on real 
world explanation - they enumerate the features, point out what button 
or knob makes an adjustment, but there is a paucity of explanation on 
how and when to use those features on the air.  This is a problem with 
many other features on these radios.  Moreover, the manuals rarely 
explain how an one feature relates to the another noise reducing 
features, including the NB Noise Blanker, BW Bandwidth, PBT Pass band, 
RF-Gain, and other controls, which, when used together, work pretty well.

Modern transceivers like the K3 have different tools for different 
problems.  I recommend a detailed web search for articles and comments 
that explain how these various systems work, in general, and which work 
best on what types of noise, in particular.  Eventually, you will 
assemble enough information to better understand how these features 
operate and interact.  I have yet to find a single, comprehensive 
explanation in real world terms... and I have looked!

Sometimes a combination of adjustments will get the click.  Sometimes 
nothings gets the click.  This research will pay dividends and you will 
learn about the K3 and other radios as well.

In any case, there are no free lunches, these tools alter incoming 
signals, causing, in turn, some level of distortion and impose unwanted 
digital "artifacts" - hopefully resulting in greater intelligibility, 
but with some fallout or deleterious impact in the signal.  You trade 
off one for the other, and hopefully don't go too far and make things 
worse, which is easy to do.  Used in moderation, audio quality is 
sacrificed to some degree to achieve better intelligibility.

The first thing you must determine is which type of noise is tackled by 
each noise reducing feature.  For example, and it varies from rig to 
rig, but generally (speaking in very general and not scientific terms 
lest I generalize too much) -  DSP NR attempts to reduce random noise 
like atmospheric static and general hiss which covers a weak signal. The 
NB Noise Blanker typically reduces repetitive pulse type noise like 
ignition sparking, and some NB circuits are geared more to reducing the 
heavier pulsing of radar systems, like what SW listeners call the 
Russian Woodpecker.   The AN or Auto Notch seeks out and removes one or 
more constant tones, like when someone is tuning his antenna tuner right 
over your QSO.  A manual notch does that manually, you gotta adjust it 
out, frequency and bandwidth are user selected.  The PBT or Pass band 
Tuning control allows you to shift the receiver pass band left of right 
to avoid a problem signal on one or the other side of the signal you 
want.  You get less of the desired signal, but maybe none or far less of 
the offending signal that way.   RF-Gain can often be used to lower 
signal and noise (so to speak) and you end up with less noise and less 
signal, but maybe a better signal-to-noise ratio where noise is less 
noticeable against the resulting signal volume.

You should research how each one works, on transceivers generally, and 
the K3 in particular, and EXPERIMENT with each individually and blended 
with others for best advantage, each situation may vary from another in 
some way.

There are few concise explanations, so it may take some time to assemble 
a comprehensive explanation, but the effort will pay dividends on your 
time investment.

Good luck.
--------------------- K8JHR  ---------------------