K3S DSP filter plots
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Although Elecraft has documented the response curves of their 5 and 8 pole roofing filters, I can't find any plots of their narrow DSP CW filters, like the 50, 100, 150 or 200 hz filters. Does anyone have Elecraft published plots of the narrow CW DSP filters, or has anyone use a signal generator to plot out their own response curves. It would be nice to know the DSP filter shape factors of the various narrow CW DSP filters to superimpose on top of the plots of the roofing filters. It would help me decide on which roofing filters to get since the roofing filters will determine how much IF shift can be achieved before the filter skirts of the DSP filters interact with the filter skirts of the fixed roofing filters. Charles K5UA ______________________________________________________________ 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 Message delivered to [hidden email] |
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> Does anyone have Elecraft published plots of the narrow CW DSP > filters, To the best of my knowledge, Elecraft have never published "curves" of the DSP response since the DSP is so dynamic. However, I remember Lyle commenting that the DSP has a constant skirt slope something on the order of 30 dB/100 Hz. 73, ... Joe, W4TV On 11/16/2015 1:24 AM, [hidden email] wrote: > > > Although Elecraft has documented the response curves of their 5 and 8 > pole roofing filters, I can't find any plots of their narrow DSP CW > filters, like the 50, 100, 150 or 200 hz filters. Does anyone have > Elecraft published plots of the narrow CW DSP filters, or has anyone use > a signal generator to plot out their own response curves. It would be > nice to know the DSP filter shape factors of the various narrow CW DSP > filters to superimpose on top of the plots of the roofing filters. It > would help me decide on which roofing filters to get since the roofing > filters will determine how much IF shift can be achieved before the > filter skirts of the DSP filters interact with the filter skirts of the > fixed roofing filters. > > Charles K5UA > 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 Message delivered to [hidden email] |
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In reply to this post by charles-2
Hi Charles,
You mention "interaction" as if it were some phenomenon to be avoided. In the K3 the roofing filter is in the analog 8 MHz IF and the DSP filter is program code working on the number soup somewhere after the RX analog to digital signal conversion. The only "interaction" possible is the sum of the two pass band losses at a given frequency for the two filter bandwidths chosen. Speaking particularly of CW contest operation there is a good deal useful to be said for aligning the -15 dB points on both slopes to create the narrowest -30 dB points when the actual roofing and DSP bandwidths are set the same. One might term this a *desired maximum* "interaction" (sum) of the two filters. This results in operating bandwidths of 450 and 350 Hz using the "400" and "250" filters respectively for the most abrupt combined skirts. When running (calling CQ and listening for answers) in a contest one needs to listen up and down a little because we get answers to our CQ's not zero beat. We need to hear that bandwidth well and then have the combined filter skirts drop off as steeply as possible beyond. This is because as routinely experienced the next running station up or down frequency can be obscenely loud. The combination of roofing and DSP filter skirts is the only defense against loud adjacent signals which are routinely up and down 500 Hz and as close as 300 Hz. When there are nearby clicky signals, the sharp combined skirt drop results in a reduced amplitude sharper click which the K3 noise blanker handles well set to DSP 2-7 and IF off. These very positive K3 behaviors are very well known among serious CW contest operators and one of the reasons for its high popularity in this group. 73, Guy K2AV On Monday, November 16, 2015, <[hidden email]> wrote: > > > Although Elecraft has documented the response curves of their 5 and 8 > pole roofing filters, I can't find any plots of their narrow DSP CW > filters, like the 50, 100, 150 or 200 hz filters. Does anyone have > Elecraft published plots of the narrow CW DSP filters, or has anyone use > a signal generator to plot out their own response curves. It would be > nice to know the DSP filter shape factors of the various narrow CW DSP > filters to superimpose on top of the plots of the roofing filters. It > would help me decide on which roofing filters to get since the roofing > filters will determine how much IF shift can be achieved before the > filter skirts of the DSP filters interact with the filter skirts of the > fixed roofing filters. > > Charles K5UA > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] <javascript:;> > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] <javascript:;> > -- Sent via Gmail Mobile on my iPhone ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by charles-2
I suspect you have researched these pages. But in case you haven't, I found
these links to be helpful. Also the KE7X book <http://www.ke7x.com/the-elecraft-k3s-book> has K3 roofing and dsp information. This is not exactly what you requested, regarding plots, but I think it may answer some questions. http://www.elecraft.com/K3/Roofing_Filters.htm http://www.elecraft.com/K3/K3_filter_plots.htm FAQ "Why would I use narrow roofing filters?" below http://www.elecraft.com/K3/K3FAQ.htm#panadaptor http://www.cliftonlaboratories.com/elecraft_k3_noise_blanker_and_crystal_dsp_filtering.htm Regards, David M. WD5M On Mon, Nov 16, 2015 at 12:24 AM, <[hidden email]> wrote: > > > Although Elecraft has documented the response curves of their 5 and 8 > pole roofing filters, I can't find any plots of their narrow DSP CW > filters, like the 50, 100, 150 or 200 hz filters. Does anyone have > Elecraft published plots of the narrow CW DSP filters, or has anyone use > a signal generator to plot out their own response curves. It would be > nice to know the DSP filter shape factors of the various narrow CW DSP > filters to superimpose on top of the plots of the roofing filters. It > would help me decide on which roofing filters to get since the roofing > filters will determine how much IF shift can be achieved before the > filter skirts of the DSP filters interact with the filter skirts of the > fixed roofing filters. > > Charles K5UA > > > ______________________________________________________________ > 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 > Message delivered to [hidden email] > 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 Message delivered to [hidden email] |
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In reply to this post by charles-2
>It would be nice to know the DSP filter shape factors of the
>various narrow CW DSP filters http://marc.info/?l=elecraft&m=120716404727944&w=2 Dave Hachadorian, K6LL Yuma, AZ . ______________________________________________________________ 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 Message delivered to [hidden email] |
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Is the reference to the DSP filter system or the roofing filter system?
Since the reference is CW xxxxx Filters, as a misnomer, one would presume the reference is actually to the roofing filters. Where as the DSP filter system is stepped from 50 Hz, 100 Hz, 150 Hz and etc. as such. 73 Bob, K4TAX On 11/16/2015 5:15 PM, Dave Hachadorian wrote: >> It would be nice to know the DSP filter shape factors of the various >> narrow CW DSP filters > > http://marc.info/?l=elecraft&m=120716404727944&w=2 > > > ______________________________________________________________ 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 Message delivered to [hidden email] |
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The DSP filtering is not stepped, but is continuously variable with the
WIDTH control. There are no discrete DSP filters. 73, Don W3FPR On 11/16/2015 7:24 PM, Bob McGraw - K4TAX wrote: > Is the reference to the DSP filter system or the roofing filter > system? Since the reference is CW xxxxx Filters, as a misnomer, one > would presume the reference is actually to the roofing filters. > Where as the DSP filter system is stepped from 50 Hz, 100 Hz, 150 Hz > and etc. as such. ______________________________________________________________ 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 Message delivered to [hidden email] |
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Looking to buy an Elecraft XG3 Signal Gen.. if you have one to sell please email me directly.
Thank you much Dan - NB1C ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Bob McGraw - K4TAX
>Is the reference to the DSP filter system or the roofing filter
>system? It is all about the DSP system. Lyle performed an experimental test of a 500 Hz DSP filter inside a 2.8 KHz roofing filter, so the DSP filter was the determinant factor. Here is his email again: http://marc.info/?l=elecraft&m=120716404727940&w=2 The inference I drew from Lyle's response is: DSP 60 dB BW = DSP Setting + 300 Hz. You can see that DSP "shape factor" varies with the DSP setting, so it is easier to remember the DSP+300 formula. Dave Hachadorian, K6LL Yuma, AZ . ______________________________________________________________ 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 Message delivered to [hidden email] |
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The narrowest filter settings (50 Hz and 100 Hz) are actually steeper than
this, and the IIR filters (menu selection) are different, too. I see all sorts of notes in this thread about S Meter readings. Much easier to turn AGC off and use the dB metering function in the radio. Of course, I admit to bias... 73, Lyle KK7P On Mon, Nov 16, 2015 at 8:38 PM, Dave Hachadorian <[hidden email]> wrote: > Is the reference to the DSP filter system or the roofing filter >> system? >> > > It is all about the DSP system. Lyle performed an experimental > test of a 500 Hz DSP filter inside a 2.8 KHz roofing filter, so > the DSP filter was the determinant factor. Here is his email > again: > http://marc.info/?l=elecraft&m=120716404727940&w=2 > > The inference I drew from Lyle's response is: > DSP 60 dB BW = DSP Setting + 300 Hz. > > You can see that DSP "shape factor" varies with the DSP setting, > so it is easier to remember the DSP+300 formula. > > Dave Hachadorian, K6LL > Yuma, AZ > > > > . > > > > ______________________________________________________________ > 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 > Message delivered to [hidden email] > 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 Message delivered to [hidden email] |
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In reply to this post by Dave Hachadorian-2
On 11/16/2015 07:38 PM, Dave Hachadorian wrote:
... > The inference I drew from Lyle's response is: > DSP 60 dB BW = DSP Setting + 300 Hz. > > You can see that DSP "shape factor" varies with the DSP setting, > so it is easier to remember the DSP+300 formula. It's worth mentioning that a similar thing happens with analog crystal filters. The shape factor gets worse the narrower the filter bandwidth. Alan N1AL ______________________________________________________________ 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 Message delivered to [hidden email] |
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