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? >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
