Re: [Elecraft] K3 Filter questions
Sheesh. Tony was just being a smart aleck (as he likes to do) and at least one of us (me) thought it was funny. On Wed, 28 Mar 2012, Ron D'Eau Claire wrote: Absolutely!! I, too, grew up in a small town (in the Southern California orange groves) and was helped by a number of Hams who stepped up immediately upon learning that I was struggling to get on the air. Their encouragement led me into a life-long career in electronics and whenever I do have the opportunity to help someone it is my way of saying thank you to those wonderful mentors. And, in spite of all of those years writing about electronics, working on electronics and building radio gear in my home workshop, it's a rare day that I don't learn something new. 73, Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Wednesday, March 28, 2012 6:46 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Filter questions I could take offense at that statement. We each speak from our level of education and information available. I thought we had a technical forum here - there are some asides (that many - hopefully most - enjoy) which interject some light-hearted comments, but (IMHO) the technical issues should be kept crisp and restricted to technical arguments in an effort to advance the state of the art and provide understanding for those hams who do not have the advantages of that obtained from an education in EE. We can help each other to learn a bit more from whatever level of understanding of Electrical Laws and Circuits we may each be at... 73, Don __ 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 -- Hisashi T Fujinaka - ht...@twofifty.com BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte __ 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
Re: [Elecraft] K3 Filter questions
If it pleases you to use DSP set wider than roofing filter - by all means, go for it. I would not, however, clame objectivity based on my subjective experience or somebody's valuable opinion and simplistic explanation , I perefer measurements performed on good lab equipment. K8ZOA did some of the measurements on 500 Hz filter, but most of them probably applicable for the 1.8kHz filter. See report here: http://www.cliftonlaboratories.com/elecraft_k3_noise_blanker_and_crystal_dsp_filtering.htm In his measuremetns, setting DSP wider than the actual roofing filter actually degraded the total response in the stop band. 73, Igor, N1YX - Original Message - From: Jim Brown j...@audiosystemsgroup.com To: elecraft@mailman.qth.net Sent: Tuesday, March 27, 2012 2:33:14 PM Subject: Re: [Elecraft] K3 Filter questions On 3/27/2012 11:12 AM, k.i...@comcast.net wrote: I am pretty sure the DSP filter is effective only if it is narrower than the roofing filter. Not at all true. When reading K6LL's comments, bear in mind that he is a VERY good operator and engineer. I value anything he has to say. I posted yesterday that I had done almost the same thing -- told the K3 that my 1.8 kHz filter was a 2 kHz filter so that it switches in at 2 kHz -- and that I was pretty pleased with the result. When there are multiple filters in any signal chain their responses combine (the proper engineering term is cascade) so that the total filtering capability is that of both added together. This is most pronounced when two filters have approximately the same bandwidth and are set to the same frequency. The way this works is that if filter #1 is rejecting by 6 dB at a given off-frequency point and filter #2 is attenuating by 4 dB, the combined rejection will be 10 dB. This is approximately what K6LL and I are doing. 73, Jim K9YC __ 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 __ 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
Re: [Elecraft] K3 Filter questions
Igor, You are missing the point. K8ZOA's measurements were for a continuous carrier. You can't measure speech intelligibility with the K3's dBV meter. My recommendation for DSP bandwidth of 2.1 KHz and 1.8 crystal filter were based on what I consider the best compromise between bandwidth and intelligibility for SSB human speech. Look at it this way - My ears find SSB speech very intelligible with a DSP bandwidth of 2.1 KHz. You can put a 1.8 crystal filter in front of that DSP and SSB STILL is very intelligible, plus you have the advantage of a nice tight roofing filter to keep the hardware AGC from pumping. When you start reducing the DSP bandwidth below 2.1 KHz, intelligibility starts to become very dependent on the voice characteristics of the received signal, so you have to keep fiddling with the DSP controls. You don't want to be fiddling with the controls if you are running at 200 QSO's per hour. I'm saying that with DSP 2.1 and a 1.8 roofing filter, one can pretty much leave the controls alone for the duration of the contest. After the contest is over, you can go back to 2.7/2.7 filters for more natural-sounding audio. Dave Hachadorian, K6LL Yuma, Arizona -Original Message- From: k.i...@comcast.net Sent: Wednesday, March 28, 2012 11:05 AM To: j...@audiosystemsgroup.com Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Filter questions If it pleases you to use DSP set wider than roofing filter - by all means, go for it. I would not, however, clame objectivity based on my subjective experience or somebody's valuable opinion and simplistic explanation , I perefer measurements performed on good lab equipment. K8ZOA did some of the measurements on 500 Hz filter, but most of them probably applicable for the 1.8kHz filter. See report here: http://www.cliftonlaboratories.com/elecraft_k3_noise_blanker_and_crystal_dsp_filtering.htm In his measuremetns, setting DSP wider than the actual roofing filter actually degraded the total response in the stop band. 73, Igor, N1YX __ 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
Re: [Elecraft] K3 Filter questions
Actually, my first point exactly is that hearing is subjective, the setting that works for you may not be good for somebody else. And there is nothing wrong with this. My other point is that from technical point of view, you reduce significance of the DSP filter with this setup, which is fact as opposed to categorical unbased statement from somebody that this is not true. That is all and I consider this thread is closed for me. 73, Igor, N1YX - Original Message - From: Dave Hachadorian k...@arrl.net To: Elecraft Reflector elecraft@mailman.qth.net Sent: Wednesday, March 28, 2012 3:55:56 PM Subject: Re: [Elecraft] K3 Filter questions Igor, You are missing the point. K8ZOA's measurements were for a continuous carrier. You can't measure speech intelligibility with the K3's dBV meter. My recommendation for DSP bandwidth of 2.1 KHz and 1.8 crystal filter were based on what I consider the best compromise between bandwidth and intelligibility for SSB human speech. Look at it this way - My ears find SSB speech very intelligible with a DSP bandwidth of 2.1 KHz. You can put a 1.8 crystal filter in front of that DSP and SSB STILL is very intelligible, plus you have the advantage of a nice tight roofing filter to keep the hardware AGC from pumping. When you start reducing the DSP bandwidth below 2.1 KHz, intelligibility starts to become very dependent on the voice characteristics of the received signal, so you have to keep fiddling with the DSP controls. You don't want to be fiddling with the controls if you are running at 200 QSO's per hour. I'm saying that with DSP 2.1 and a 1.8 roofing filter, one can pretty much leave the controls alone for the duration of the contest. After the contest is over, you can go back to 2.7/2.7 filters for more natural-sounding audio. Dave Hachadorian, K6LL Yuma, Arizona -Original Message- From: k.i...@comcast.net Sent: Wednesday, March 28, 2012 11:05 AM To: j...@audiosystemsgroup.com Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Filter questions If it pleases you to use DSP set wider than roofing filter - by all means, go for it. I would not, however, clame objectivity based on my subjective experience or somebody's valuable opinion and simplistic explanation , I perefer measurements performed on good lab equipment. K8ZOA did some of the measurements on 500 Hz filter, but most of them probably applicable for the 1.8kHz filter. See report here: http://www.cliftonlaboratories.com/elecraft_k3_noise_blanker_and_crystal_dsp_filtering.htm In his measuremetns, setting DSP wider than the actual roofing filter actually degraded the total response in the stop band. 73, Igor, N1YX __ 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 __ 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
Re: [Elecraft] K3 Filter questions
On Wed, Mar 28, 2012 at 5:31 PM, k.i...@comcast.net wrote: ...fact as opposed to categorical unbased statement from somebody... Ah but Igor, you are trying to argue from evidence. That's a no-no. The way to prove your point is to assert it in CAPS. Then and only then will you be right. Tony KT0NY -- http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352 __ 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
Re: [Elecraft] K3 Filter questions
On 3/28/2012 12:55 PM, Dave Hachadorian wrote: You are missing the point. K8ZOA's measurements were for a continuous carrier. You can't measure speech intelligibility with the K3's dBV meter. Exactly right. 73, Jim K9YC __ 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
Re: [Elecraft] K3 Filter questions
I could take offense at that statement. We each speak from our level of education and information available. I thought we had a technical forum here - there are some asides (that many - hopefully most - enjoy) which interject some light-hearted comments, but (IMHO) the technical issues should be kept crisp and restricted to technical arguments in an effort to advance the state of the art and provide understanding for those hams who do not have the advantages of that obtained from an education in EE. We can help each other to learn a bit more from whatever level of understanding of Electrical Laws and Circuits we may each be at. Taking snipes at each other because some lack the background to understand the technical language is offensive to me. Helping another ham to understand what is going on, is exciting to me. If I may, I want to inject some of my background. I knew nothing of radio stuff, but I was interested, and that was when I was a teen (15 years old). The Boy Scout troop I was involved with announced that the East Palestine Radio Club was offering lessons in learning the Morse Code and other radio endeavors, I was interested. and went to those classes. That club got me started in ham radio. This was a small town in Ohio where everyone knew everyone else. Be that good or bad (and it had points in both directions), the East Palestine Radio Club had many elmers for me. They first provided the means where I could have my novice license, and then when I was constructing my homebrew novice transmitter (I could not afford to buy a kit), they provided support and assistance. The folks in that club helped me in making my first contacts, and helped me gently along the way. The encouragement I got from the members of that club as I contemplated college and a career were well received. I ended up with a BSEE degree because of their encouragement. It is enlightening that none of them were BSEE graduates although a couple of them were BSME graduates. They were not necessarily experts in what I was trying to accomplish, but they were experts in communicating that I was on the right track and I should continue/ I am thankful to that collection of radio amateurs from a small town in Ohio for my direction and my career whichever way that has evolved - no regrets. The point I am offering is that there is no need to provide assertions in CAPS. You will be right and recognized as such by intelligent statements using good English words (some folks get careless here and make themselves look uneducated in the use of words that sound the same but are spelled differently. - there is different from their is only one example). The use of proper English language will elevate your comments in my mind, and the incorrect use of similar sounding words - hear vs. here, - there vs. their, - eye vs. I , - hare vs. hair, - bare vs. bear, and numerous others tell me that the education level in this country is diminishing rapidly. When I see written communication from school teachers that contain similar errors of syntax and grammar, I wonder where we are all headed - do the dictionaries of this world have to bow to those distortions of normal writing? I hope not. OK, Off topic RANT aside, I do feel that there should be many technical points offered in CAPS just because they are electronics principles that should withstand syntax and positive, and other simialar sounding but different meaning and spelling That is a way to make statements stand out from the crowd, but I do agree that excessive use of CAPS is counterproductive. In internet etiquette, caps are equal to YELLING, and should be avoided because most list members will put beans in their ears when they see all caps. 73, Don On 3/28/2012 7:54 PM, Tony Estep wrote: On Wed, Mar 28, 2012 at 5:31 PM,k.i...@comcast.net wrote: ...fact as opposed to categorical unbased statement from somebody... Ah but Igor, you are trying to argue from evidence. That's a no-no. The way to prove your point is to assert it in CAPS. Then and only then will you be right. Tony KT0NY __ 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
Re: [Elecraft] K3 Filter questions
Absolutely!! I, too, grew up in a small town (in the Southern California orange groves) and was helped by a number of Hams who stepped up immediately upon learning that I was struggling to get on the air. Their encouragement led me into a life-long career in electronics and whenever I do have the opportunity to help someone it is my way of saying thank you to those wonderful mentors. And, in spite of all of those years writing about electronics, working on electronics and building radio gear in my home workshop, it's a rare day that I don't learn something new. 73, Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Wednesday, March 28, 2012 6:46 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Filter questions I could take offense at that statement. We each speak from our level of education and information available. I thought we had a technical forum here - there are some asides (that many - hopefully most - enjoy) which interject some light-hearted comments, but (IMHO) the technical issues should be kept crisp and restricted to technical arguments in an effort to advance the state of the art and provide understanding for those hams who do not have the advantages of that obtained from an education in EE. We can help each other to learn a bit more from whatever level of understanding of Electrical Laws and Circuits we may each be at... 73, Don __ 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
Re: [Elecraft] K3 Filter questions
2.8, 2.1, 400 - no need to go tighter IMO. Before buying a 1.8, I suggest spending time on someone's K3 with a 1.8 if you can. I think you would find it fatiguing to listen to for more than a few minutes. Certainly not a rag chewing filter. Jack - WE5ST On Mar 26, 2012, at 7:48 PM, Dave \(K7DRT\) dtull...@earthlink.net wrote: I am still studying the K3 and the various options I use. I still plan to purchase one. My previous radios (IC-756PRO the last one) I used 2.4 khz and 1.8 kHz for SSB and 500 hz 250 hz for CW / Data. The K3 comes with a 2.7 kHz 5-pole filter. My SSB questions are: from your experience, 1) which is better for a narrow filter for SSB; 2.1 khz or 1.8 kHz? 2) Which is more useful, 2.7 kHz 5-pole or 2.8 kHz 8-pole? My Data question: Is the 400 kHz 8-pole adequate or should I purchase an additional (250 hz or 200 hz) filter? Thanks 73 de Dave K7DRT P.S. I did read the “K3 Crystal 'Roofing' Filters” It was very helpful. __ 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 __ 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
Re: [Elecraft] K3 Filter questions
Dave, 1. I prefer the 2.1 filter for SSB, 1.8 can potentially give a slight edge when the bands are extremely crowded, but generally speaking I use the 2.7 and narrow down to 2.1 if there is much QRM, remember that with the DSP you can go as low as you want, so it only makes a real difference if the interfering signal is way stronger than the one you want to copy. So in the end I swapped my 1.8kHz filter for an extra 500Hz filter for the sub receiver. 2. I haven't tried the 2.8kHz 8-pole filter, it has sharper edges than the 2.7k one and some people prefer it. I have the 6kHz 8-pole filter as well (for ESSB/SWL broadcast listening) and if the transmitting station is using a wide TX filter for SSB it sounds better with that in. Again, the DSP does a lot of the work so I don't think there is that much difference between the 2.7 and 2.8 filters, if I was to buy a new rig I'd probably opt for the 2.8 one, but not a strong preference. I think the main difference is slightly sharper edges on TX, and negligible on RX. 3. I have found the 400Hz filter perfectly adequate for CW and digimodes. A 1kHz filter would be much more useful, and I will probably get it eventually, but the 250Hz filter doesn't seem that useful to me. 400Hz gives enough of a context to make a weak CW signal stand out particularly when APF filter is on. For digimodes, I've copied a few PSK31 signals that I could not copy with 400Hz because it was drowned out by a very strong signal elsewhere in the passband, but I've never had this happen with a signal that was less than 400Hz away, remember you can adjust the width and center frequency independently and the K3 chooses the best crystal filter for the job, so you can move the rx window left or right to avoid any interfering strong signal close to the one you want to copy. All in all I'm very satisfied with my filter lineup which is: Main RX: FL1 - None yet (KFL3B-FM 13kHz FM filter on order, for operating FM on 10m and with transverters in the future) FL2 - KFL3A-6K (for AM/ESSB receive (and rarely used ESSB TX)) FL3 - 2.7kHz 5-pole filter FL4 - KFL3A-2.1 (for SSB and digimodes) FL5 - KFL3A-400 (for CW and digimodes) Sub RX: FL1 - None FL2 - None FL3 - 2.7kHz 5-pole filter FL4 - None FL5 - KFL3A-400 I wish I had room for 1 more filter, so I could have the 1kHz filter for use with wider digimodes and a wider PSK31 passband. Most of the time for PSK31 it is not necessary to go down to the 400Hz filter to copy the weakest signals, but 1kHz would be better when the bands are crowded. I don't think a 250 or 200Hz would confer any real advantage. 73, Thomas M0TRN On 27 March 2012 01:48, Dave (K7DRT) dtull...@earthlink.net wrote: I am still studying the K3 and the various options I use. I still plan to purchase one. My previous radios (IC-756PRO the last one) I used 2.4 khz and 1.8 kHz for SSB and 500 hz 250 hz for CW / Data. The K3 comes with a 2.7 kHz 5-pole filter. My SSB questions are: from your experience, 1) which is better for a narrow filter for SSB; 2.1 khz or 1.8 kHz? 2) Which is more useful, 2.7 kHz 5-pole or 2.8 kHz 8-pole? My Data question: Is the 400 kHz 8-pole adequate or should I purchase an additional (250 hz or 200 hz) filter? Thanks 73 de Dave K7DRT P.S. I did read the “K3 Crystal 'Roofing' Filters” It was very helpful. __ 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 __ 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
Re: [Elecraft] K3 Filter questions
*Jack, with respect I would disagree with your assessment of the 1.8Khz filter. From experience, I had both the 2.1 and 1.8 fitted and by judicious use of the Hi Cut/Lo Cut adjustment I find the 1.8 far better in practice. Audio quality is easily made pleasant to the ear without introduction of any artifacts that are not wanted and provides a better blocking of nearby strong stations. Many of us have anywhere from mild to extensive hearing issues which vary from one person to another. In my case it is Tinitus and therefore it is essential for me to use a headset and combining the 1.8khz filter with the Yamaha CM-500 I find the audio pleasant. Just last weekend I participated in the VK Field Day contest and spent a solid 24 hours on air with little problem other than sleep deprivation..:-) A quick check of local K3's here in VK4 reveals many are using the 1.8khz filter in preference to the 2.1Khz filter for SSB use. The 400 is popular for CW/Digital use. If your hearing is somewhere in the normal range I do envy you and perhaps the 2.1Khz filter is more to your liking. Regards, Gary * On 27 March 2012 17:58, Jack Berry jlbe...@yahoo.com wrote: 2.8, 2.1, 400 - no need to go tighter IMO. Before buying a 1.8, I suggest spending time on someone's K3 with a 1.8 if you can. I think you would find it fatiguing to listen to for more than a few minutes. Certainly not a rag chewing filter. Jack - WE5ST On Mar 26, 2012, at 7:48 PM, Dave \(K7DRT\) dtull...@earthlink.net wrote: I am still studying the K3 and the various options I use. I still plan to purchase one. My previous radios (IC-756PRO the last one) I used 2.4 khz and 1.8 kHz for SSB and 500 hz 250 hz for CW / Data. The K3 comes with a 2.7 kHz 5-pole filter. My SSB questions are: from your experience, 1) which is better for a narrow filter for SSB; 2.1 khz or 1.8 kHz? 2) Which is more useful, 2.7 kHz 5-pole or 2.8 kHz 8-pole? My Data question: Is the 400 kHz 8-pole adequate or should I purchase an additional (250 hz or 200 hz) filter? Thanks 73 de Dave K7DRT P.S. I did read the “K3 Crystal 'Roofing' Filters” It was very helpful. __ 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 __ 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 -- Gary VK4FD - Motorhome Mobile Elecraft Equipment K3 #679, KPA-500 #018 Living the dream!!! __ 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
Re: [Elecraft] K3 Filter questions
I used the 1.8 for the entire WPX SSB contest, with a DSP width of 2.1 KHz. It sounded great. I never messed with any of the settings for the entire contest. To get this combination of DSP=2.1 and crystal=1.8, one has to install the 1.8 filter as if it were a 2.1, so it switches in at DSP=2.1. This installation setup is most easily done using the K3 Utility. In practice, normalize, then use high cut until the filter switches in. To me, the audio sounds best using that technique. WPX SSB is traditionally the worst-case QRM-fest, and the 1.8 filter was just the ticket for dealing with it. Dave Hachadorian, K6LL Yuma, Arizona From experience, I had both the 2.1 and 1.8 fitted and by judicious use of the Hi Cut/Lo Cut adjustment I find the 1.8 far better in practice. __ 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
Re: [Elecraft] K3 Filter questions
I am pretty sure the DSP filter is effective only if it is narrower than the roofing filter. In your setup the DSP filter is pretty much turned off. Please, don't forget, the crystal filters in K3 are ROOFING filters, they are protecting next IF stages and the DSP from strong near by signals, improving dynamic range . The main filtering is done in DSP. There is white paper on the matter somewhere on Elecraft web site (by Eric S). 73, Igor, N1YX - Original Message - From: Dave Hachadorian k...@arrl.net To: Elecraft Reflector elecraft@mailman.qth.net Sent: Tuesday, March 27, 2012 12:52:51 PM Subject: Re: [Elecraft] K3 Filter questions I used the 1.8 for the entire WPX SSB contest, with a DSP width of 2.1 KHz. It sounded great. I never messed with any of the settings for the entire contest. To get this combination of DSP=2.1 and crystal=1.8, one has to install the 1.8 filter as if it were a 2.1, so it switches in at DSP=2.1. This installation setup is most easily done using the K3 Utility. In practice, normalize, then use high cut until the filter switches in. To me, the audio sounds best using that technique. WPX SSB is traditionally the worst-case QRM-fest, and the 1.8 filter was just the ticket for dealing with it. Dave Hachadorian, K6LL Yuma, Arizona From experience, I had both the 2.1 and 1.8 fitted and by judicious use of the Hi Cut/Lo Cut adjustment I find the 1.8 far better in practice. __ 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 __ 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
Re: [Elecraft] K3 Filter questions
On 3/27/2012 11:12 AM, k.i...@comcast.net wrote: I am pretty sure the DSP filter is effective only if it is narrower than the roofing filter. Not at all true. When reading K6LL's comments, bear in mind that he is a VERY good operator and engineer. I value anything he has to say. I posted yesterday that I had done almost the same thing -- told the K3 that my 1.8 kHz filter was a 2 kHz filter so that it switches in at 2 kHz -- and that I was pretty pleased with the result. When there are multiple filters in any signal chain their responses combine (the proper engineering term is cascade) so that the total filtering capability is that of both added together. This is most pronounced when two filters have approximately the same bandwidth and are set to the same frequency. The way this works is that if filter #1 is rejecting by 6 dB at a given off-frequency point and filter #2 is attenuating by 4 dB, the combined rejection will be 10 dB. This is approximately what K6LL and I are doing. 73, Jim K9YC __ 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
Re: [Elecraft] K3 Filter questions
I haven't looked at the spec for the 1.8 filter but I second what Dave was saying, the specified filter bandwidths are (I think) -3dB and the curve is obviously not completely straight down, so there is still signals outside the passband. I have told my K3 that the 400Hz CW filters are really 500Hz, which means the 2.1kHz filter only kicks in when I move above 500Hz, which allows me a slightly wider passband e.g. when calling CQ, this works extremely well for me, and from looking at the waterfall the extra 50Hz on each side are getting through the filter well enough. I'm sure operating the 1.8kHz filter as a 2.1 one would work as well, although I never tried it myself, it might actually be a better setup than the 2.1 filter for contest use. 73, Thomas M0TRN On 27 March 2012 19:12, k.i...@comcast.net wrote: I am pretty sure the DSP filter is effective only if it is narrower than the roofing filter. In your setup the DSP filter is pretty much turned off. Please, don't forget, the crystal filters in K3 are ROOFING filters, they are protecting next IF stages and the DSP from strong near by signals, improving dynamic range . The main filtering is done in DSP. There is white paper on the matter somewhere on Elecraft web site (by Eric S). 73, Igor, N1YX - Original Message - From: Dave Hachadorian k...@arrl.net To: Elecraft Reflector elecraft@mailman.qth.net Sent: Tuesday, March 27, 2012 12:52:51 PM Subject: Re: [Elecraft] K3 Filter questions I used the 1.8 for the entire WPX SSB contest, with a DSP width of 2.1 KHz. It sounded great. I never messed with any of the settings for the entire contest. To get this combination of DSP=2.1 and crystal=1.8, one has to install the 1.8 filter as if it were a 2.1, so it switches in at DSP=2.1. This installation setup is most easily done using the K3 Utility. In practice, normalize, then use high cut until the filter switches in. To me, the audio sounds best using that technique. WPX SSB is traditionally the worst-case QRM-fest, and the 1.8 filter was just the ticket for dealing with it. Dave Hachadorian, K6LL Yuma, Arizona From experience, I had both the 2.1 and 1.8 fitted and by judicious use of the Hi Cut/Lo Cut adjustment I find the 1.8 far better in practice. __ 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 __ 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 __ 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
Re: [Elecraft] K3 Filter questions
Jim, I think you will find that it is true for the K3 because the roofing filter is selected by the DSP filter setting if you have the correct filters entered. You could, I suppose fool the software by entering the wrong filters in the setup, but the K3 will switch when the DSP setting crosses the roofing filter bandwidth. This may not be true for brands K,Y,I or T and I don't know about the K2, K1 etc. Willis 'Cookie' Cooke K5EWJ Trustee N5BPS, USS Cavalla, USS Stewart From: Jim Brown j...@audiosystemsgroup.com To: elecraft@mailman.qth.net Sent: Tuesday, March 27, 2012 1:33 PM Subject: Re: [Elecraft] K3 Filter questions On 3/27/2012 11:12 AM, k.i...@comcast.net wrote: I am pretty sure the DSP filter is effective only if it is narrower than the roofing filter. Not at all true. When reading K6LL's comments, bear in mind that he is a VERY good operator and engineer. I value anything he has to say. I posted yesterday that I had done almost the same thing -- told the K3 that my 1.8 kHz filter was a 2 kHz filter so that it switches in at 2 kHz -- and that I was pretty pleased with the result. When there are multiple filters in any signal chain their responses combine (the proper engineering term is cascade) so that the total filtering capability is that of both added together. This is most pronounced when two filters have approximately the same bandwidth and are set to the same frequency. The way this works is that if filter #1 is rejecting by 6 dB at a given off-frequency point and filter #2 is attenuating by 4 dB, the combined rejection will be 10 dB. This is approximately what K6LL and I are doing. 73, Jim K9YC __ 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 __ 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
