Re: [Elecraft] K3: killing RX key clicks
Are you sure about 2.5 ms? Yes. As far as I remember I measured my K3 to about 5 ms and Elecraft also stated 5 ms. This was over a year ago... Measure it again. The rise time changed roughly around the F/W 3.00 revision. I went back to a 2.xx version and it measured ~ 6 msec. Paul, W9AC __ 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: killing RX key clicks
Paul Christensen wrote: Are you sure about 2.5 ms? Yes. As far as I remember I measured my K3 to about 5 ms and Elecraft also stated 5 ms. This was over a year ago... Measure it again. The rise time changed roughly around the F/W 3.00 revision. I went back to a 2.xx version and it measured ~ 6 msec. Paul, W9AC Ok Elecraft changed it, something I missed. It was prior to 3.00 I measured. / SM2EKM __ 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: killing RX key clicks
On Wed, 02 Dec 2009 16:40:20 +0100, Jan Erik Holm wrote: Ok Elecraft changed it, something I missed. One of the (many) benefits of Elecraft's use of DSP is the ability to shape keying in the more sophisticated ways that W4TV has described. This allows clicks to be minimized without excessively softening the CW. 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: killing RX key clicks
Paul Christensen wrote: The 'RC rise/decay' wave shape that was in the handbooks for many years is actually a *bad* shape because it has a very sharp corner on key-up. Ian, *bad* may be a bit too harsh. The League's optimized envelope was described during a time when only simple R/C values were used to develop a keyed envelope. I'm not sure how one would have produced an economical Blackman-Harris or raised cosine function until say...the early to mid '90s. How would you have done it? Probably the only solution at the time was to set leading and trailing edges produced by the R/C network so soft that they're painful to copy. My criticism was that because R/C shaping was judged to be the only available technology, it was wrongly promoted as being the optimum that designers should aim for. Given better information, I believe designers could have produced analog circuits to approximate the true optimum shape... but that didn't happen. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek __ 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] K3: killing RX key clicks
Stewart, I'm starting a new thread on this subject because your post reminded me to write in on the subject. Since a key click is an impulse of signal to the RX, perhaps they could be reduced by a noise blanker type of function. That will make it even more impossible to know that you're close to an offending station! Now, if we could just cancel the offending station's signal all together, there will be no more QRM! -- 73 -- Brian -- K1LI On Tue, Dec 1, 2009 at 4:41 AM, GW0ETF gw0...@btinternet.com wrote: Ref key clicks. adjust the onboard system which emits anti-phase sound to cancel the engine noise and so make them silent to other vessels nearby. So I wonder if it might be feasible to develop a system on the K3 to use the 2nd rx to listen to the offending signal and the software produce an anti-phase 'key click' in the main receiving bandwidth to cancel the clicks...? 73, Stewart Rolfe, GW0ETF (GW6W in cqww..) __ 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: killing RX key clicks
Already done. Using roofing and DSP width that are closely matched, a clicky signal that is down very steep skirts will be converted into pulses. The roofing and DSP skirts need to **combine to be as steep as possible**. Set the NB to off for IF, and use DSP settings 2-7 or 3-7. I've had 3-7 suppress S9+10 key clicks to S3 (ABS noise level) in some instances, and able to use slow AGC as if the offending signal were not there. 2-7 makes the CW sound somewhat mushy, 3-7 makes CW signals sound real mushy, but fully readable. I routinely use NB set to DSP 2-7, no IF, just for this purpose. I use the 250 Hz (really 310 or 320) 8 pole narrow CW filter defined to the radio as 350 Hz and 350 DSP to live with ghastly clicks from a signal up 400 Hz while running. 73, Guy. On Tue, Dec 1, 2009 at 8:25 AM, Brian Machesney nekvts...@gmail.com wrote: Stewart, I'm starting a new thread on this subject because your post reminded me to write in on the subject. Since a key click is an impulse of signal to the RX, perhaps they could be reduced by a noise blanker type of function. That will make it even more impossible to know that you're close to an offending station! Now, if we could just cancel the offending station's signal all together, there will be no more QRM! -- 73 -- Brian -- K1LI On Tue, Dec 1, 2009 at 4:41 AM, GW0ETF gw0...@btinternet.com wrote: Ref key clicks. adjust the onboard system which emits anti-phase sound to cancel the engine noise and so make them silent to other vessels nearby. So I wonder if it might be feasible to develop a system on the K3 to use the 2nd rx to listen to the offending signal and the software produce an anti-phase 'key click' in the main receiving bandwidth to cancel the clicks...? 73, Stewart Rolfe, GW0ETF (GW6W in cqww..) __ 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: killing RX key clicks
Key clicks can be generated by several different mechanisms within the receiver itself. Paradoxically, it's easier to produce false clicks with a high performance receiver than it is with a lesser receiver. These have nothing to do with the transmitted signal. The first line of defense is to turn off the Preamp and turn on the Attenuator to reduce the overall strength of the signals. Next is to set the AGC to Slow to ensure a strong signal isn't within the roofing filter bandpass and triggering the AGC while the variable DSP filter is set narrow so the beat note isn't heard. In some cases using the RF gain to control the level helps a great deal. Another approach is to use a narrower roofing filter or to shift your bandpass so the edge of the roofing filter is very close to the desired signal on the side toward the interfering station and as far from the interfering station as possible. Shifting the bandpass may require you open up your DSP bandwidth to continue to hear the desired signal or shifting the DSP filter position within the roofing filter bandpass. And, remember, clicks are an essential component of a CW signal. They are the sidebands created by modulating (keying) the signal. Very careful shaping of the keying envelope, such as used in the K2 and K3, can minimize clicks while maintaining an easily readable signal, but the only way to completely eliminate clicks is to not key the signal at all. With a really high-performance you can snuggle up very close to a signal, as many here have noted. When you do that, you're much more likely to hear the essential clicks required for good keying. Ron AC7AC __ 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: killing RX key clicks
All good suggestions, Ron -- including turning off the NB if not mentioned previously. Engaging the NB function oftentimes produces internally-generated clicks. Paul, W9AC - Original Message - From: Ron D'Eau Claire r...@cobi.biz To: 'Elecraft Reflector' elecraft@mailman.qth.net Sent: Tuesday, December 01, 2009 12:51 PM Subject: Re: [Elecraft] K3: killing RX key clicks Key clicks can be generated by several different mechanisms within the receiver itself. Paradoxically, it's easier to produce false clicks with a high performance receiver than it is with a lesser receiver. These have nothing to do with the transmitted signal. The first line of defense is to turn off the Preamp and turn on the Attenuator to reduce the overall strength of the signals. Next is to set the AGC to Slow to ensure a strong signal isn't within the roofing filter bandpass and triggering the AGC while the variable DSP filter is set narrow so the beat note isn't heard. In some cases using the RF gain to control the level helps a great deal. Another approach is to use a narrower roofing filter or to shift your bandpass so the edge of the roofing filter is very close to the desired signal on the side toward the interfering station and as far from the interfering station as possible. Shifting the bandpass may require you open up your DSP bandwidth to continue to hear the desired signal or shifting the DSP filter position within the roofing filter bandpass. And, remember, clicks are an essential component of a CW signal. They are the sidebands created by modulating (keying) the signal. Very careful shaping of the keying envelope, such as used in the K2 and K3, can minimize clicks while maintaining an easily readable signal, but the only way to completely eliminate clicks is to not key the signal at all. With a really high-performance you can snuggle up very close to a signal, as many here have noted. When you do that, you're much more likely to hear the essential clicks required for good keying. Ron AC7AC __ 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: killing RX key clicks
Great information. Too bad it isn't possible to make K3 DSP changes via macros. I wouldn't want to use those settings all the time in a contest, but it would be nice to quickly jump to them with the push of a K3 button or N1MM function key when needed. 73, Dave AB7E Guy Olinger K2AV wrote: Already done. Using roofing and DSP width that are closely matched, a clicky signal that is down very steep skirts will be converted into pulses. The roofing and DSP skirts need to **combine to be as steep as possible**. Set the NB to off for IF, and use DSP settings 2-7 or 3-7. I've had 3-7 suppress S9+10 key clicks to S3 (ABS noise level) in some instances, and able to use slow AGC as if the offending signal were not there. 2-7 makes the CW sound somewhat mushy, 3-7 makes CW signals sound real mushy, but fully readable. I routinely use NB set to DSP 2-7, no IF, just for this purpose. I use the 250 Hz (really 310 or 320) 8 pole narrow CW filter defined to the radio as 350 Hz and 350 DSP to live with ghastly clicks from a signal up 400 Hz while running. 73, Guy. On Tue, Dec 1, 2009 at 8:25 AM, Brian Machesney nekvts...@gmail.com wrote: Stewart, I'm starting a new thread on this subject because your post reminded me to write in on the subject. Since a key click is an impulse of signal to the RX, perhaps they could be reduced by a noise blanker type of function. That will make it even more impossible to know that you're close to an offending station! Now, if we could just cancel the offending station's signal all together, there will be no more QRM! -- 73 -- Brian -- K1LI __ 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: killing RX key clicks
I'll accept all of that, but it still doesn't change the fact that there are some rigs out there that generate bad key clicks for no reason other than the fact that their users either don't realize it or don't care enough to fix them. When I first received my Icom 756Pro (now my backup rig) several years ago I discovered that the default rise/fall times (adjustable in one of the menus) was set to 2 msec (!). That's unconscionable, but I'll bet the majority of Icom users never bothered to check it. Many of the Yaesu rigs generate horrible key clicks unless their users have performed a simple hardware modification on them (see the info at W8JI.com). I operated about 36 hours in the contest this last weekend and made over a thousand contacts using the 8-pole 250Hz roofing filter. Many times I'd be running a frequency within 200 Hz of a S9+30db station without even knowing he was there. Other times I'd hear key clicks (loud enough to cover the dits in callsigns I was trying to copy) from stations I couldn't even find while tuning with the subreceiver! One large M/M operation had great sounding signals on all bands except 15m, where the key clicks were objectionable two KHz away even when their signal was S5-S7. At least in that case they have promised to find the problem and fix it. Actually, there is a third reason why some stations have bad key clicks. They admit they do it on purpose in a contest because it gives them more elbow room. In my experience with the K3 in several major contests since I bought it last January, the very great majority of bad signals I've heard on the air have been due to the TX on the other end, not the RX on my end. 73, Dave AB7E Ron D'Eau Claire wrote: Key clicks can be generated by several different mechanisms within the receiver itself. Paradoxically, it's easier to produce false clicks with a high performance receiver than it is with a lesser receiver. These have nothing to do with the transmitted signal. The first line of defense is to turn off the Preamp and turn on the Attenuator to reduce the overall strength of the signals. Next is to set the AGC to Slow to ensure a strong signal isn't within the roofing filter bandpass and triggering the AGC while the variable DSP filter is set narrow so the beat note isn't heard. In some cases using the RF gain to control the level helps a great deal. Another approach is to use a narrower roofing filter or to shift your bandpass so the edge of the roofing filter is very close to the desired signal on the side toward the interfering station and as far from the interfering station as possible. Shifting the bandpass may require you open up your DSP bandwidth to continue to hear the desired signal or shifting the DSP filter position within the roofing filter bandpass. And, remember, clicks are an essential component of a CW signal. They are the sidebands created by modulating (keying) the signal. Very careful shaping of the keying envelope, such as used in the K2 and K3, can minimize clicks while maintaining an easily readable signal, but the only way to completely eliminate clicks is to not key the signal at all. With a really high-performance you can snuggle up very close to a signal, as many here have noted. When you do that, you're much more likely to hear the essential clicks required for good keying. Ron AC7AC __ 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: killing RX key clicks
On Tue, 01 Dec 2009 11:29:24 -0700, David Gilbert wrote: In my experience with the K3 in several major contests since I bought it last January, the very great majority of bad signals I've heard on the air have been due to the TX on the other end, not the RX on my end. Strongly agree. And I strongly DISAGREE with Ron's statement that clicks are an essential part of CW. Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. There's a KH6 contester who moved from K4 with a monster signal, monster clicks, monster SSB splatter, and monster attitude to go with it. I've told him about his clicks and splatter several times, but the clicks, splatter, and attitude are still there. 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: killing RX key clicks
And I strongly DISAGREE with Ron's statement that clicks are an essential part of CW. Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. There's a KH6 contester who moved from K4 with a monster signal, monster clicks, monster SSB splatter, and monster attitude to go with it. I've told him about his clicks and splatter several times, but the clicks, splatter, and attitude are still there. 73, Jim K9YC Not sure if you checked his signal in the last couple contests? If so you are criticizing a K3 for having monster Klix and SSB splatter. He has ran a K3 now for some time. He is 40 to 50 over nine here on 160 meters and I can get within less than 1/2KC and copy the weakest DX signals, so have to say K3 to K3 I dont have any problems with him. I do have problems with a couple other KH6 stations on that same island, they have klix and splatter that covers several KC of the band and they are only 20 over 9. Understand the radio is only as good as the operator setting it up, but that goes for both ends of the QSO. Merv KH7C __ 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: killing RX key clicks
While on 160m a few nights ago I heard loud key clicks and tracked it down to a ham just 1 mile away who was chasing a DX station. When he transmitted, my K3 was rendered totally deft from any signal within 10 Khz of him! My 200hz roofing filter, ATTN, preamp off and RFG down had no effect. I guess even the K3 has it's limits. Steve N4LQ n...@carolina.rr.com - Original Message - From: David Gilbert xda...@cis-broadband.com To: Ron D'Eau Claire r...@cobi.biz Cc: 'Elecraft Reflector' elecraft@mailman.qth.net Sent: Tuesday, December 01, 2009 1:29 PM Subject: Re: [Elecraft] K3: killing RX key clicks I'll accept all of that, but it still doesn't change the fact that there are some rigs out there that generate bad key clicks for no reason other than the fact that their users either don't realize it or don't care enough to fix them. When I first received my Icom 756Pro (now my backup rig) several years ago I discovered that the default rise/fall times (adjustable in one of the menus) was set to 2 msec (!). That's unconscionable, but I'll bet the majority of Icom users never bothered to check it. Many of the Yaesu rigs generate horrible key clicks unless their users have performed a simple hardware modification on them (see the info at W8JI.com). I operated about 36 hours in the contest this last weekend and made over a thousand contacts using the 8-pole 250Hz roofing filter. Many times I'd be running a frequency within 200 Hz of a S9+30db station without even knowing he was there. Other times I'd hear key clicks (loud enough to cover the dits in callsigns I was trying to copy) from stations I couldn't even find while tuning with the subreceiver! One large M/M operation had great sounding signals on all bands except 15m, where the key clicks were objectionable two KHz away even when their signal was S5-S7. At least in that case they have promised to find the problem and fix it. Actually, there is a third reason why some stations have bad key clicks. They admit they do it on purpose in a contest because it gives them more elbow room. In my experience with the K3 in several major contests since I bought it last January, the very great majority of bad signals I've heard on the air have been due to the TX on the other end, not the RX on my end. 73, Dave AB7E Ron D'Eau Claire wrote: Key clicks can be generated by several different mechanisms within the receiver itself. Paradoxically, it's easier to produce false clicks with a high performance receiver than it is with a lesser receiver. These have nothing to do with the transmitted signal. The first line of defense is to turn off the Preamp and turn on the Attenuator to reduce the overall strength of the signals. Next is to set the AGC to Slow to ensure a strong signal isn't within the roofing filter bandpass and triggering the AGC while the variable DSP filter is set narrow so the beat note isn't heard. In some cases using the RF gain to control the level helps a great deal. Another approach is to use a narrower roofing filter or to shift your bandpass so the edge of the roofing filter is very close to the desired signal on the side toward the interfering station and as far from the interfering station as possible. Shifting the bandpass may require you open up your DSP bandwidth to continue to hear the desired signal or shifting the DSP filter position within the roofing filter bandpass. And, remember, clicks are an essential component of a CW signal. They are the sidebands created by modulating (keying) the signal. Very careful shaping of the keying envelope, such as used in the K2 and K3, can minimize clicks while maintaining an easily readable signal, but the only way to completely eliminate clicks is to not key the signal at all. With a really high-performance you can snuggle up very close to a signal, as many here have noted. When you do that, you're much more likely to hear the essential clicks required for good keying. Ron AC7AC __ 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.709 / Virus Database
Re: [Elecraft] K3: killing RX key clicks
When I first received my Icom 756Pro (now my backup rig) several years ago I discovered that the default rise/fall times (adjustable in one of the menus) was set to 2 msec (!). That's unconscionable... It's unconscionable with some rigs, but not all. Take a look at the K3's keying envelope on a scope since the ca. 3.00 firmware release earlier this year. Compare it against the QST Product Reviews. I currently measure the rise time of about 2.5 msec and the K3 occupies minimal RF spectrum. Even at very fast CW speeds, it's the slope of the rise and fall that primarily determines occupied bandwidth. As keying speed increases, there's a point where the keying rate becomes a dominant factor but that's largely due to the fact that as the keying rate increases so must the envelope slope. The clicks heard with many transmitters occurs because the slope is discontinuous. Using a Blackman-Harris or raised-cosine window function minimizes occupied bandwidth but that function is also dependent on envelope distortion created by a transmitter's ALC circuitry. So, it's possible to set two completely different brands of transmitters to 2 msec and the bandwidth results can be radically different. Paul W9AC __ 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: killing RX key clicks
Not once in my experience has the K3 NB made clicks worse (that's N*B* I'm talking about, not N*R*). I gave a formula in an earlier post in this thread. I invite anyone to actually try it and see. NR does not seem to do anything for or against clicks. 73, Guy. On Tue, Dec 1, 2009 at 12:57 PM, Paul Christensen w...@arrl.net wrote: All good suggestions, Ron -- including turning off the NB if not mentioned previously. Engaging the NB function oftentimes produces internally-generated clicks. Paul, W9AC - Original Message - From: Ron D'Eau Claire r...@cobi.biz To: 'Elecraft Reflector' elecraft@mailman.qth.net Sent: Tuesday, December 01, 2009 12:51 PM Subject: Re: [Elecraft] K3: killing RX key clicks Key clicks can be generated by several different mechanisms within the receiver itself. Paradoxically, it's easier to produce false clicks with a high performance receiver than it is with a lesser receiver. These have nothing to do with the transmitted signal. The first line of defense is to turn off the Preamp and turn on the Attenuator to reduce the overall strength of the signals. Next is to set the AGC to Slow to ensure a strong signal isn't within the roofing filter bandpass and triggering the AGC while the variable DSP filter is set narrow so the beat note isn't heard. In some cases using the RF gain to control the level helps a great deal. Another approach is to use a narrower roofing filter or to shift your bandpass so the edge of the roofing filter is very close to the desired signal on the side toward the interfering station and as far from the interfering station as possible. Shifting the bandpass may require you open up your DSP bandwidth to continue to hear the desired signal or shifting the DSP filter position within the roofing filter bandpass. And, remember, clicks are an essential component of a CW signal. They are the sidebands created by modulating (keying) the signal. Very careful shaping of the keying envelope, such as used in the K2 and K3, can minimize clicks while maintaining an easily readable signal, but the only way to completely eliminate clicks is to not key the signal at all. With a really high-performance you can snuggle up very close to a signal, as many here have noted. When you do that, you're much more likely to hear the essential clicks required for good keying. Ron AC7AC __ 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: killing RX key clicks
On Tue, 01 Dec 2009 08:55:55 -1000, Merv Schweigert wrote: Not sure if you checked his signal in the last couple contests? If so you are criticizing a K3 for having monster Klix and SSB splatter. The exciter is not the ONLY click or trash generator in a station. ANY non-linear device can produce splatter and clicks. An overdriven power amp can create clicks and splatter. The most common way that happens is depending on ALC to reduce the drive to hit the desired TX power. A poorly tuned power amp will also produce clicks and splatter. A VERY well known contester and K3 user lives about 15 miles from me. His clicks and splatter make life miserable for several of his neighbors including K6RB, K6XX, and me. He's otherwise a nice guy and a member of our club, but he's long been in denial about the trash on his signal. It IS better since he converted to K3s a couple of years ago, but his splatter was 10 kHz wide during SS. Another guy, a casual operator and sometimes contester, runs a high priced ICOM rig into a high priced auto-tune power amp. He's also a click generator. 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: killing RX key clicks
Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. Not quite ... keyclicks are often a second derivative effect. They occur when the rate of change of the rate of change is high - specifically at the corners of the waveform (a abrupt change in the slope coupled with high power levels). At one time W8JI had some scope and spectrum samples of CW waveforms with slow rise/fall rates but very bad clicks. In every case the ramp was fine but there was an abrupt change when the ramp reached the steady state (on) condition or at instant of transition from the steady state (on) condition to the start of the decay phase. These effects can be most readily observed in rigs with high IF gain as they are quite similar to clicks generated in the old class C amplifiers as the drive level passed from AB into hard C. 73, ... Joe, W4TV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: Tuesday, December 01, 2009 1:42 PM To: Elecraft List Subject: Re: [Elecraft] K3: killing RX key clicks On Tue, 01 Dec 2009 11:29:24 -0700, David Gilbert wrote: In my experience with the K3 in several major contests since I bought it last January, the very great majority of bad signals I've heard on the air have been due to the TX on the other end, not the RX on my end. Strongly agree. And I strongly DISAGREE with Ron's statement that clicks are an essential part of CW. Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. There's a KH6 contester who moved from K4 with a monster signal, monster clicks, monster SSB splatter, and monster attitude to go with it. I've told him about his clicks and splatter several times, but the clicks, splatter, and attitude are still there. 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: killing RX key clicks
It's basic physics, Jim. A keyed signal is amplitude modulated and an amplitude modulated signal produces sidebands. Your are quite right that the rise time affects the amount of spectrum the sidebands make. Of course, higher keying speeds require faster rise and fall times, otherwise one code element would begin before the fall time allowed the previous element to stop. Indeed, the way to reduce clicks is to extend the rise and fall times. The slower the rise and fall the less click energy around the carrier. In the extreme you make the rise and fall times infinite (that is, you don't key the carrier at all). Then you'll have no sidebands (clicks) at all. If you modulated the signal 100% with a pure sine wave, you'd only have two sidebands at discrete frequencies above and below the carrier separated by the frequency of the modulating signal. The issue with CW is that we don't use a sine wave. No matter how we look at it, we distort the keying signal by stopping it at the point the carrier is full on during the rise and full off at the fall. That distortion produces further sideband energy beyond the sideband produced by the keying waveform. Advanced shaping techniques such as those used in the K3 minimize that energy in the sidebands, but it's still there. Poorly designed and operated rigs can produce keying sidebands far in excess of what's needed for good communications, just as poorly designed and operated AM or SSB rigs produce sidebands far in excess of what's needed. It sounds like you've run into one of those. I think anyone who spends enough time on the CW bands will find them. They come from two sources. One is the design of the rig itself. You are quite right that some rigs are better than others. Considering that just about any transmitter built since the demise of spark in the 1920's is perfectly legal on our bands today, sometimes it's a limitation of the design. Among current designs, some are better than others. The other is operator error. In these days of mostly factory-designed and built rigs, it's usually caused by over-driving an amplifier in the mistaken belief that linearity isn't important in CW. Linearity is very important to retain the keying waveform of the rig driving the amplifier, just as it's very important to preserve the waveform of an SSB signal. It's also why it's bad practice to turn the POWER knob on a K3 or K2 full clockwise, even on CW. IMD (distortion) increases as you go past the rated 100 watts output. On CW distortion is heard as clicks as Jim notes. Indeed, for over half a century that I know of, we've always defined clicks as excessive CW sidebands, recognizing that normal sidebands are always present. Until fairly recently, it was not possible to listen to the sidebands in a CW signal using a typical communications receiver without hearing the carrier too. They were just too close together. Nowadays our advanced receivers can split the sideband off of the keyed signal, just as for years we've been able to split the sidebands off of an AM signal. On CW those sidebands sound like clicks. Ron AC7AC -Original Message- And I strongly DISAGREE with Ron's statement that clicks are an essential part of CW. Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. There's a KH6 contester who moved from K4 with a monster signal, monster clicks, monster SSB splatter, and monster attitude to go with it. I've told him about his clicks and splatter several times, but the clicks, splatter, and attitude are still there. 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: killing RX key clicks
I suspect that over-driving an external amplifier is a major cause of excessive clicks on the bands today. Many Hams think that CW doesn't require the final amplifier be linear and drive their rigs into saturation. But a linear amplifier needs to be linear for CW just as with any amplitude modulation (SSB, AM, CW, etc.) Ron AC7AC -Original Message- It IS better since he converted to K3s a couple of years ago, but his splatter was 10 kHz wide during SS. Another guy, a casual operator and sometimes contester, runs a high priced ICOM rig into a high priced auto-tune power amp. He's also a click generator. 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: killing RX key clicks
Joe Subich, W4TV wrote: Clicks are a function of a FAST RISE TIME and DISTORTION, not keying speed. Not quite ... keyclicks are often a second derivative effect. They occur when the rate of change of the rate of change is high - specifically at the corners of the waveform (a abrupt change in the slope coupled with high power levels). At one time W8JI had some scope and spectrum samples of CW waveforms with slow rise/fall rates but very bad clicks. In every case the ramp was fine but there was an abrupt change when the ramp reached the steady state (on) condition or at instant of transition from the steady state (on) condition to the start of the decay phase. Correct - both the overall rise/fall time and absence of sharp corners are important. W9CF shows that an optimum wave shape has a gradual start, accelerating to a more rapid rise/fall through the middle part, and then slowing to a more gradual finish. The 'RC rise/decay' wave shape that was in the handbooks for many years is actually a *bad* shape because it has a very sharp corner on key-up. Another factor that can cause nasty key-clicks from a K3 is the default TX delay of 8ms. This may not be enough time for some amplifiers to change over, causing clicks due to hot-switching. This time can be increased using CONFIG / TX DLY. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek __ 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: killing RX key clicks
On Tue, 1 Dec 2009 16:52:00 -0500, Joe Subich, W4TV wrote: Not quite ... keyclicks are often a second derivative effect. They occur when the rate of change of the rate of change is high - specifically at the corners of the waveform (a abrupt change in the slope coupled with high power levels). No disagreement from me on this -- you're simply looking at it in greater detail than my simpllification. 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: killing RX key clicks
I suspect that over-driving an external amplifier is a major cause of excessive clicks on the bands today. Many Hams think that CW doesn't require the final amplifier be linear and drive their rigs into saturation. But a linear amplifier needs to be linear for CW just as with any amplitude modulation (SSB, AM, CW, etc.) Key clicks also occur when bias is suddenly applied to an amp where the transceiver is already producing an RF envelope. I recently experienced this when I purchased the SPE 1K-FA solid-state amp. The amp is advertised as being Full QSK compatible. However, it uses general purpose frame relays at the RF input and output. As such, the firmware is programmed to apply bias at a very long 15 msec after the amp's relay line is pulled low by the transceiver. The problem isn't terribly bad with a transceiver like the K3 as its RF envelope can be delayed in the K3 menu. However, rigs like the Icom 7700 and 7800 produce RF at ~ 9 msec. after key closure and there's no menu to adjust it. On the scope, WYSIWYG. In the K3's default setting of 8 msec., my SPE amp was hot switching as a result of bias being applied at 15 msec when the K3 was already producing its RF envelope at exactly 12 msec after key closure. And so, the RF envelope was being truncated by 3 msec in full QSK mode. SPE chose that bias time to give the general-purpose frame relays an opportunity to settle without contact bounce. Sure, the amp's relays were not being hot-switched, but the effect of key clicks is the same when the sudden onset of bias causes the FET output transistors to instantly conduct, producing a sharp vertical rise time of the RF envelope. I then delayed the K3 to 16 msec and the hot-switch problem disappeared. But in doing so, the keyed elements were also being shortened, albeit without RF hot-switching. That fix requires use of pulse-stretching key compensation using an external keyer. Next, I tried using the K3's TX INH handshake with the SPE amp. More dit shortening problems. Was the problem with the K3 or the SPE amp. I honestly don't know and don't care. I only care that there's a viable solution is available. Really, the only way to cleanly fix these problems is at the source of the timing issue. The solution: I ended up modifying a beat-up Ameritron QSK-5, keeping the logic interface between the QSK-5 and the SPE amp100% optically-isolated. http://72.52.250.47/images/QSK-5-Interface.pdf Now, instead of the amp's firmware setting the bias activation time, the QSK-5 tells the SPE amp when to apply bias. QSK is pretty awesome with this set-up and even the first leading 'dit' switches cleanly with no keyed element shortening. Long-term, the fix calls for using a Gigavac GH-1 vacuum relay at the amp's output and an Aromat RSD-12V RF reed relay at the amp's input. SPE has sent me the revised firmware that reduces bias time to 8 msec, but that requires an EEPROM programmer and a spare chip that I need to order. But with either solution, bias key clicks won't be a problem. Paul, W9AC __ 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: killing RX key clicks
The 'RC rise/decay' wave shape that was in the handbooks for many years is actually a *bad* shape because it has a very sharp corner on key-up. Ian, *bad* may be a bit too harsh. The League's optimized envelope was described during a time when only simple R/C values were used to develop a keyed envelope. I'm not sure how one would have produced an economical Blackman-Harris or raised cosine function until say...the early to mid '90s. How would you have done it? Probably the only solution at the time was to set leading and trailing edges produced by the R/C network so soft that they're painful to copy. Myself, I actually prefer the R/C keying as shown in those issues of the ARRL Handbook for reasons that Ron cited. What I like is a slightly fast leading edge, but an exponential trail of the falling edge. Irrational? Yes, I'll admit it. My favorite rig to listen during a CW rag-chew is either the Drake T-4XC or TR-7. Both produce nearly identical keyed envelopes. And, yes, neither are optimized for minimal bandwidth. However, with just a bit of help on the leading edge, keying bandwidth can be kept reasonably narrow. Paul, W9AC __ 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: killing RX key clicks
Paul Christensen wrote: When I first received my Icom 756Pro (now my backup rig) several years ago I discovered that the default rise/fall times (adjustable in one of the menus) was set to 2 msec (!). That's unconscionable... It's unconscionable with some rigs, but not all. Take a look at the K3's keying envelope on a scope since the ca. 3.00 firmware release earlier this year. Compare it against the QST Product Reviews. I currently measure the rise time of about 2.5 msec and the K3 occupies minimal RF spectrum. Even at very fast CW speeds, it's the slope of the rise and fall that primarily determines occupied bandwidth. As keying speed increases, there's a point where the keying rate becomes a dominant factor but that's largely due to the fact that as the keying rate increases so must the envelope slope. The clicks heard with many transmitters occurs because the slope is discontinuous. Using a Blackman-Harris or raised-cosine window function minimizes occupied bandwidth but that function is also dependent on envelope distortion created by a transmitter's ALC circuitry. So, it's possible to set two completely different brands of transmitters to 2 msec and the bandwidth results can be radically different. Paul W9AC Are you sure about 2.5 ms? As far as I remember I measured my K3 to about 5 ms and Elecraft also stated 5 ms. This was over a year ago however, if 2.5 is correct they have changed it or my memmory is corrupted. / SM2EKM __ 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
