Noise Reduction parameters
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Can someone enlighten me about setting up the NR parameters....hope I can explain myself ok!
Holding ADJ brings up (at vfo B position) - <NR F#-*> where * is from 1 to 4 for each value of # and is adjusted with vfo B knob and clearly increase the degree of noise reduction. As you continue to rotate vfo B knob, # cycles from 1 to 4 but there doesn't appear any discernible difference for each value of #. Can't find any reference in the manual so curiosity has driven me here.; did wonder at first if NR settings were per filter but there are 5 filter positions and in K3 0145 just 3 filters so that theory is out the window. Having said all that the noise reduction works a real treat..... 73, Stewart Rolfe, GW0ETF |
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> Can someone enlighten me about setting up the NR parameters....hope I can
> explain myself ok! The NR has changed with time and may continue to do so. As a result, the manual is general in its treatment. The overall rule is "more is more." NR is more properly Signal Enhancement rather than Noise Reduction. The distinction is subtle but important if you wish to understand how it works and how to best apply it. If ti were noise reduction, the implication is that it passes everything until it figures out what is more likely to be noise, which it then attempts to suppress. Since it is signal enhancement, it tends to pass nothing until it figures out that which is more likely signal, which it then attempts to pass. With this understanding there is one more concept I must explain: correlation. This is the degree to which a signal is similar to itself; conversely, it can be used to figure out how noise is dis-similar to itself (more random). This is the basis on which NR works. In the current implementation of the K3, we have four (4) basic NR filters. These are displayed as F1..F4. F1 is the gentlest, F4 the most aggressive. Recalling that the filters tend to suppress everything until they can sort out what is probably a signal, there is some time delay involved in their application. Further, especially with voice signals, some components of the signal may not be recognized as well as others. THis gives rise to distortion. So, we added a second field to the NR. This is the -1..-4 which specifies a certain amount of "bleed through" of the original signal. This reduces the apparent distortion and delay, but limits the ultimate S/N improvement. -1 provides the least distortion but limits the S/N improvement on weak to moderate signals to about 6 dB. -4 provides no "mixing" whatsoever and can result in dramatic S/N improvements, but at a cost of slight time delays and increased distortion. NR is not appropriate for very weak signals, so a -1 or -2 is best if you wish to hear them. Having saids al this, the correct way to use the NR is to listen and adjust it for the best compromise between noise reduction and distortion. Everyone is different in this regard. Some tolerate noise better than others, while some don't tolerate distortion very well at all. I live in a quiet location, and use NR1-2 as my most common setting. This is low in distortion, allows me to hear weak signals, and shows no apparent delay as I tune through the bands. On the rare occasions when things get noisy here, I crank it to higher values. Probably a much longer answer than you wished. Merry Christmas, Lyle KK7P _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Chuck, AE4CW |
Re: Noise Reduction parameters
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In reply to this post by KK7P
Lyle Johnson wrote:
> Probably a much longer answer than you wished. NO!! This is exactly the kind of thing I (for one) want to hear and understand. Would like much more of this kind of technical presentation on the K3's design and operation. Those who don't want this kind of in-depth response can simply delete. Bill W5WVO K3 in February '08 > > Merry Christmas, > > Lyle KK7P > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I second that, perhaps a page with write-ups and post to the reflector to
tell us when a new on is there On 22/12/07 17:43, "Bill W5WVO" <[hidden email]> sent: > Lyle Johnson wrote: > >> Probably a much longer answer than you wished. > > NO!! This is exactly the kind of thing I (for one) want to hear and > understand. Would like much more of this kind of technical presentation on the > K3's design and operation. Those who don't want this kind of in-depth response > can simply delete. > > Bill W5WVO > K3 in February '08 Why should I fear death? If I am, death is not. If death is, I am not. Why should I fear that which cannot exist when I do? -Epicurus, philosopher (c. 341-270 BCE) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On Sun, 23 Dec 2007, David Ferrington, M0XDF wrote:
> I second that, perhaps a page with write-ups and post to the reflector to > tell us when a new on is there An alternative would be to announce here that a wiki page with the information had been created. http://www.zerobeat.net/mediawiki/index.php/Main_Page 73 k3hrn Thom,EIEIO Email, Internet, Electronic Information Officer www.baltimorehon.com/ Home of the Baltimore Lexicon www.tlchost.net/hosting/ Web Hosting as low as 3.49/month _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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