K3 filters
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Hi all,
I am going to add a narrow filter to my K3 order for data modes mainly but also CW I guess :-) Which narrow filter do you think I should choose? I am only using the stock 2.7kHz filter otherwise. Ian -- Ian J Maude, G0VGS SysOp GB7MBC DX Cluster Member RSGB, GQRP K2 #4044 |K3 #? _______________________________________________ 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 have 250Hz and 1kHz, a fair combination.
On digital I rarely switch them in, on CW I love the sound with the 250Hz. Simon Brown, HB9DRV ----- Original Message ----- From: "Ian J Maude" <[hidden email]> > > I am going to add a narrow filter to my K3 order for data modes mainly > but also CW I guess :-) > > Which narrow filter do you think I should choose? I am only using the > stock 2.7kHz filter otherwise. > _______________________________________________ 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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Simon
I would be interested to hear what that "sound" is. I have been disappointed with narrow cw filters in the past. What sort of cw speed is it comfortable with? Could you put a sound file onto your website? I know it is going to be doubly digitised via the internet, but it might give me a clue. David G3UNA > On digital I rarely switch them in, on CW I love the sound with the 250Hz. > > Simon Brown, HB9DRV > _______________________________________________ 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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In reply to this post by Ian Maude
My question is which CW filter SOUNDS the best? I'm sensitive to
ringing. My Omni V rang badly with the narrow filters. I want a CW filter that minimizes ringing. Should I go narrow 5-pole or wider 8-pole? - Keith N1AS - - K2 5411.ssb.100 - - K3 Wave 3 - -----Original Message----- Which narrow filter do you think I should choose? I am only using the stock 2.7kHz filter otherwise. _______________________________________________ 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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In reply to this post by David Cutter
OK,
Actually I can make good quality MP3 files using some dodgy software I came across - will post back later. At the moment there's only 40m available... Simon Brown, HB9DRV ----- Original Message ----- From: "David Cutter" <[hidden email]> > I would be interested to hear what that "sound" is. I have been > disappointed with narrow cw filters in the past. What sort of cw speed is > it comfortable with? Could you put a sound file onto your website? I > know it is going to be doubly digitised via the internet, but it might > give me a clue. _______________________________________________ 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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Here's a WAV recording ftp://ftp.ham-radio.ch/common/K3%20CW%20Demo.WAV
I listen using a Hi-Fi speaker, when I play back through my PC speakers they seem to ring. You hear me using 1 kHz for tuning about, then when I have a signal it's down to the 250Hz filter, then at the end I dropped it down to 50Hz using the DSP. What I hear in the headphones is better than the playback here for some reason, so what you will hear is better. Couldn't find any high-speed merchants this evening. Simon Brown, HB9DRV ----- Original Message ----- From: "Simon Brown (HB9DRV)" <[hidden email]> > > Actually I can make good quality MP3 files using some dodgy software I > came across - will post back later. At the moment there's only 40m > available... > _______________________________________________ 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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In reply to this post by Darwin, Keith
Keith,
An 8-pole filter should have more ringing than a 5-pole filter of the same bandwidth and ripple. That's because the loaded Q of each pole (crystal) is higher (bandwidth of each pole is narrower). You can think of it as each crystal covering 1/8 of the bandwidth rather than 1/5, although that's an oversimplification. Al N1AL On Fri, 2007-11-30 at 09:23, Darwin, Keith wrote: > My question is which CW filter SOUNDS the best? I'm sensitive to > ringing. My Omni V rang badly with the narrow filters. I want a CW > filter that minimizes ringing. > > Should I go narrow 5-pole or wider 8-pole? > > - Keith N1AS - > - K2 5411.ssb.100 - > - K3 Wave 3 - _______________________________________________ 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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Yes, that is what the theory says, but I think there is variation in
filter implementations such that some 8 pole filters ring worse than others. With the DSP, one approach is to use a 5 pole filter to get a less ringy first filter followed by the DSP which adds the extra selectivity to achieve the ultimate rejection and elimination of signals outside the roofing filter. This might give great selectivity with less ringing than trying to put all that selectivity in the crystal filter. - Keith N1AS - - K2 5411.ssb.100 - - K3 Wave 3 - -----Original Message----- From: Alan Bloom [mailto:[hidden email]] An 8-pole filter should have more ringing than a 5-pole filter of the same bandwidth and ripple. That's because the loaded Q of each pole (crystal) is higher (bandwidth of each pole is narrower). You can think of it as each crystal covering 1/8 of the bandwidth rather than 1/5, although that's an oversimplification. _______________________________________________ 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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For the same passband ripple and bandwidth I think more poles pretty
much invariably means more ringing. By the way, many people think that DSP-based filters don't ring. Actually, a digital filter's impulse response, measured at say the half-power point, is pretty comparable to an analog (e.g. cyrstal) filter with the same ripple and bandwidth. However, the ringing from a digital FIR (finite impulse response) filter eventually drops all the way to zero, while an IIR (e.g. analog) filter theoretically rings forever. Since human sound perception tends to be logarithmic, the ringing _sounds_ longer with the analog filter. Al N1AL On Fri, 2007-11-30 at 12:06, Darwin, Keith wrote: > Yes, that is what the theory says, but I think there is variation in > filter implementations such that some 8 pole filters ring worse than > others. > > With the DSP, one approach is to use a 5 pole filter to get a less ringy > first filter followed by the DSP which adds the extra selectivity to > achieve the ultimate rejection and elimination of signals outside the > roofing filter. This might give great selectivity with less ringing > than trying to put all that selectivity in the crystal filter. > > - Keith N1AS - > - K2 5411.ssb.100 - > - K3 Wave 3 - > > -----Original Message----- > From: Alan Bloom [mailto:[hidden email]] > > An 8-pole filter should have more ringing than a 5-pole filter of the > same bandwidth and ripple. That's because the loaded Q of each pole > (crystal) is higher (bandwidth of each pole is narrower). You can think > of it as each crystal covering 1/8 of the bandwidth rather than 1/5, > although that's an oversimplification. > _______________________________________________ > 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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In reply to this post by Simon (HB9DRV)
K3 owners: is this recording representative of what the K3 actually sounds like? Are there recordings out there?
Thanks, John K7FD ---- "Simon Brown (HB9DRV)" <[hidden email]> wrote: > Here's a WAV recording ftp://ftp.ham-radio.ch/common/K3%20CW%20Demo.WAV > > _______________________________________________ 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 meant to say are there OTHER recordings out there...fat fingers... 73 John K7FD ---- [hidden email] wrote: > K3 owners: is this recording representative of what the K3 actually sounds like? Are there recordings out there? > > Thanks, > > John K7FD > > > ---- "Simon Brown (HB9DRV)" <[hidden email]> wrote: > > Here's a WAV recording ftp://ftp.ham-radio.ch/common/K3%20CW%20Demo.WAV > > > > > _______________________________________________ > 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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In reply to this post by Alan Bloom
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In reply to this post by Ian Maude
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In reply to this post by wolfmanjack
It's a 16-bit mono recording taken via the line-out using a high-quality
soundcard (USInterface.com Navigator). The K3 operator isn't all that skilled but he's got half a clue as to what's going on (on a good day at least). The antennas was a sloping 20m dipole, radio tuned to 40m with preamp on. After tidying up the pigsty I'll see if 20m is alive and make another recording before getting on with mode coding. Simon Brown, HB9DRV ----- Original Message ----- From: <[hidden email]> > K3 owners: is this recording representative of what the K3 actually sounds > like? _______________________________________________ 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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In reply to this post by AC7AC
Ron,
Isn't it funny that whenever you accidentally omit a word from a sentence, it's always the one word that completely alters the meaning of the sentence in the most significant way possible? :-) I believe this is yet another corollary to Murphy's Law... Bill / W5WVO (Technical Writer/Editor/Artist in my other life) Ron D'Eau Claire wrote: > Oops I meant to say: > > "Ringing is a function of the bandwidth and only SLIGHTLY affected by > the type of filter." > > -----Original Message----- > From: Ron D'Eau Claire [mailto:[hidden email]] > Sent: Friday, November 30, 2007 8:52 PM > To: '[hidden email]' > Subject: RE: [Elecraft] K3 filters > > > Any filter will produce "ringing" when the bandwidth is too small. > > Ringing is a function of the bandwidth and only affected by the type > of filter. In some filter designs it's possible for some elements of > the filter to have such a high Q they ring even though the overall > filter bandpass is not that small, but that's a aberration in the > filter design. > > Ringing typically occurs when the bandwidth at either the transmitter > or receiver is restricted too much to allow the CW sidebands to pass > through. > > Of course, the sidebands on a CW signal are the frequencies > represented by the rise and fall of each CW element. If the bandwidth > isn't sufficient to pass them, the element is stretched out in time > as the amplitude decays, just like the amplitude of a bell decays > after the bell was stuck. That's what we call "ringing". > > Ron AC7AC > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Alan Bloom > Sent: Friday, November 30, 2007 1:47 PM > To: Darwin, Keith > Cc: [hidden email] > Subject: RE: [Elecraft] K3 filters > > > For the same passband ripple and bandwidth I think more poles pretty > much invariably means more ringing. > > By the way, many people think that DSP-based filters don't ring. > Actually, a digital filter's impulse response, measured at say the > half-power point, is pretty comparable to an analog (e.g. cyrstal) > filter with the same ripple and bandwidth. However, the ringing from > a digital FIR (finite impulse response) filter eventually drops all > the way to zero, while an IIR (e.g. analog) filter theoretically > rings forever. Since human sound perception tends to be logarithmic, > the ringing _sounds_ longer with the analog filter. > > Al N1AL > > > _______________________________________________ > 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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In reply to this post by Simon (HB9DRV)
Simon Brown (HB9DRV) wrote:
> OK, > > Actually I can make good quality MP3 files using some dodgy software I > came across - will post back later. At the moment there's only 40m > available... > Slightly off topic but... Have any of you considered using FLAC to encode these files? It would afford much greater fidelity at the expense of a slightly larger file. And for much larger files one could set up a torrent. Just a thought. Nick N2SVT _______________________________________________ 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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Simple answer - no, but I'll look at this when I get time. At the moment I
prefer MP3 and wave files. Simon Brown, HB9DRV ----- Original Message ----- From: "Nick Lidakis" <[hidden email]> > > Have any of you considered using FLAC to encode these files? > It would afford much greater fidelity at the expense of a slightly larger > file. And for much larger files one could set up a torrent. > _______________________________________________ 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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