[Elecraft] Best way to use NB and NR?

[ROBERT HARMON]

Wow Don,  great explanation !

Bob
K6UJ




On Sep 29, 2011, at 8:51 PM, Don Wilhelm wrote:

> The K3 noise blanker, and in fact any noise blanker works by producing 
> "holes" in the receive path.  That is what blanking means - if an 
> impulse is detected, it shuts off the receive path for a specified 
> period of time.
> 
> That will not "take away" from the reception of faint signals, but if 
> combined with gaps in the received signals because of impulse events 
> occurring at the receiving station, it may make the copy of faint 
> signals difficult because of the blanks in the received data stream.
> 
> In my opinion, it should only be used when necessary, not all the time.  
> If you have constant static pulses or automotive ignition noise or 
> distant lightning surge problems at your QTH, then it may be beneficial 
> to run the NB at all times, but if you do not need it, keep it off.  
> Remember that the NB responds to impulse noise - it will not be 
> effective in reducing slow rise time noise like atmospheric noise or 
> power-line induced noise.  NB needs a fast rise time to be effective.
> 
> NR is a different animal altogether.  It will reduce or eliminate things 
> like atmospheric noise or power line noise - it works on correlation 
> principles.  That means is it is normally quiet while it looks for what 
> might be a valid signal.  When it finds something that appears to be a 
> valid signal, it builds a filter around it and sends that result to the 
> K3 audio.  What it looks for is highly dependent on the parameters set 
> for the K3 NR algorithm as well as your local noise.  There are several 
> settings provided for in the menu.  Do a little experimenting with your 
> chosen mode and local noise situation until you discover what works best 
> for you.  The settings for CW will likely not be good for SSB.  Try the 
> settings to find which works for your particular situation.  This is not 
> a case of "one size fits all", customize it to your particular noise 
> source.   With NR on, the desired signal should be enhanced, but really 
> weak signals may be at or near the noise level, and may not appear as a 
> valid signal, giving the appearance that weak signals may be covered up 
> and not detected.  I suggest (after experimenting) that you normally run 
> with NR turned off, but turn it on if the situation warrants it.
> 
> 73,
> Don W3FPR
> 
> On 9/29/2011 12:15 PM, tomb18 wrote:
>> Hi,
>> I was wondering if anyone could give me some hints as to the best way to use
>> the NB and the NR?
>> Most of the time I use the nr and there seems to be little effect of the nb
>> (maybe one-two s units?)  Does the nb take away from faint signals?  If not
>> should I always just use it?
>> 
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