Re-reading Wayne's suggestion I can see that he meant to try the DSP NB, not the DSP NR. I just did so. At t1-4 the tuning pulses were noticeably weaker, but mostly still there. At t1-7 they were mostly gone but still audible.
Anyway, since I can't even hear the tuning pulses with an antenna connected, I personally don't need to do anything about them. However, since I started playing with the NR, I have continued playing with it for general noise reduction. In my previous message I forgot to mention the effect of the NR 1-4 on the general audio level. The reason is I didn't notice any volume decrease on 20 m CW where signals as well as noise were strong. On the other hand, when I tuned in the very weak carrier on 28060, turning on the NB caused a very noticeable loss of volume on the wanted signal. With a scope I verified that the NR F1-4 didn't much affect the volume on the strong CW signals on 20, while with the weak signal on 10 it made the wanted signal much weaker, and made the noise weaker still. Yes, the NR definitely improved the S/N ratio on the weak signal, but overall system gain was only marginal with both volume controls at maximum. With the strong signals on 20, the NR also improved S/N but without attenuating the wanted signal. On both bands the bandwidth was 1 kHz and the AGC F was on (since the NR can't be turned on unless the AGC is on). AGC PLS ON, AGC SLP 4, AGC THR 7. It looks like the NR function behaves very differently when the signal level is very low. I wonder how this relates to the working conditions in the DSP including the AGC part of it. 73, Erik K7TV ----- Original Message ----- From: "Erik N Basilier" <ebasil...@cox.net> To: "Elecraft Reflector" <elecraft@mailman.qth.net> Sent: Wednesday, March 25, 2009 1:39 PM Subject: Re: [Elecraft] K3 Tuning encoder pulses and birdie problem > Hearing absolutely nothing from the receiver with the 1-4 NR setting on > the > dummy load felt a bit unsettling. I then connected a real antenna and > tuned > up the band until I heard a very weak real signal. Not only does the band > noise completely cover up the "encoder ticks" in my location, but also the > band noise as well as the very weak signal do get past the noise > reduction, > so that I hear band noise all the time at any frequency with the 1-4 NR > setting active (more noise with the preamp on, as expected), making the > rig > sound normal to this non-squelch guy. When I switch to the dummy load, the > radio goes completely quiet even with the preamp on and both gain controls > at maximum. That is OK with me since I don't really want to hear anything > on > the dummy antenna anyway. > Next I tried leaving the 1-4 NR active on 20 CW. With the 1 kHz bandwidth > and CW, the this mild NR setting removes so much noise that it is > comparable > to reducing the bandwidth to 200 Hz. On 20 SSB this NR setting had little > effect on the voice audio, but it did reduce noise a lot. I used to turn > on > NR only when needed, but will try to try leaving it on routinely. I don't > have time for firmware download today but plan to do it fairly soon. > > 73, > Erik K7TV ______________________________________________________________ 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
