K3 filter ringing at 50Hz
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I was wondering if anybody else has noticed this or is it just me. With 3.30
firmware I am noticing some ringing on CW with the DSP bandwidth at 50Hz. It clears up at 100Hz. I don't remember hearing this with earlier firmware. I haven't tried reloading older firmware. I considered that this was a function of my listening to a lot of weak stations in noisy band conditions this past month while chasing DXpeditions. But today I have been on 20 meters in the CA QSO party. The band is quiet and the signals are strong but the ringing is still there at 50Hz. My narrow xtal filter is the 5 pole 200Hz filter and I am making these assessments with NR off and RX EQ flat. 73, Mike K2MK ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I'm running a pre-release beta (f/w ver 3.41). Hardware is an 8 pole 250
Hz filter and no NR. I am using a centre frequency/pitch of 700 Hz. On 80m this evening (8pm local) there is little difference between 50 Hz and wider settings of the DSP bandwidth on both weak and strong signals, the band is fairly quiet. I don't often go that narrow as few can net within 300 Hz let alone 50 Hz, so have little experience of using that bandwidth, but it sounds fine here on my K3. NR has little effect on CW at very narrow bandwidths like 50 Hz, however it doesn't make the signal ring at any level of NR setting. 73 Dave, G4AON K3/100 #80 ============== I was wondering if anybody else has noticed this or is it just me. With 3.30 firmware I am noticing some ringing on CW with the DSP bandwidth at 50Hz. It clears up at 100Hz. I don't remember hearing this with earlier firmware. I haven't tried reloading older firmware. <SNIP> Mike K2MK ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Mike K2MK
If you have selected the IIR filter using CONFIG:FLx BW - tap 1 (instead
of the default FIR filter), you are more likely to experience ringing with narrow DSP filters. See page 24 (Narrow DSP Filter Types) of the K3 Owner's manual. 73, Ted, W2ZK K2MK wrote: > I was wondering if anybody else has noticed this or is it just me. With 3.30 > firmware I am noticing some ringing on CW with the DSP bandwidth at 50Hz. It > clears up at 100Hz. I don't remember hearing this with earlier firmware. I > haven't tried reloading older firmware. > > I considered that this was a function of my listening to a lot of weak > stations in noisy band conditions this past month while chasing DXpeditions. > But today I have been on 20 meters in the CA QSO party. The band is quiet > and the signals are strong but the ringing is still there at 50Hz. My narrow > xtal filter is the 5 pole 200Hz filter and I am making these assessments > with NR off and RX EQ flat. > > 73, > Mike K2MK > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Sorry, it's "tap 7" instead of "tap 1".
Ted Ted Roycraft wrote: > If you have selected the IIR filter using CONFIG:FLx BW - tap 1 (instead > of the default FIR filter), you are more likely to experience ringing > with narrow DSP filters. See page 24 (Narrow DSP Filter Types) of the > K3 Owner's manual. > > 73, Ted, W2ZK > > K2MK wrote: > >> I was wondering if anybody else has noticed this or is it just me. With 3.30 >> firmware I am noticing some ringing on CW with the DSP bandwidth at 50Hz. It >> clears up at 100Hz. I don't remember hearing this with earlier firmware. I >> haven't tried reloading older firmware. >> >> I considered that this was a function of my listening to a lot of weak >> stations in noisy band conditions this past month while chasing DXpeditions. >> But today I have been on 20 meters in the CA QSO party. The band is quiet >> and the signals are strong but the ringing is still there at 50Hz. My narrow >> xtal filter is the 5 pole 200Hz filter and I am making these assessments >> with NR off and RX EQ flat. >> >> 73, >> Mike K2MK >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> 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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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