[Elecraft] K3 Narrow CW Filter
I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? Thanks in advance. 73 de K1ESE John __ 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 Narrow CW Filter
John Huffman-3 wrote: I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. John, I had the following from Vic K2VCO in response to a post by me about Noise Reduction and RX Equalisation settings - I had it boosted at the cw sidetone frequency to give an accentuated effect with NR but found my audio dropped when I reduced the b/w beyond the 150 Hz point. So you may want to check/play with your RX Eq settings This is not the best approach because of the following: when the 50 and 100 Hz DSP filters are enabled the RX EQ is disabled (I forgot the reason for this, but Lyle explained it to me). So the effect of narrowing the bandwidth is that the signal suddenly drops several dB! If you want to use the RX EQ for this the best way to do it is to leave the desired bands at 0 dB and *reduce* all others by the amount of 'boost' that you prefer. -- 73, Vic, K2VCO All this cross referencing of previous posts would be so much easier if each post was numbered as on some other reflectors. 73, Stewart Rolfe, GW0ETF -- View this message in context: http://n2.nabble.com/K3-Narrow-CW-Filter-tp2258338p2258751.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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 Narrow CW Filter
Adding a little to these comments: I operate a lot of CW on traffic nets, and with props the way they are, often have to deal with pretty weak signals on 40m. The NR function works well to make an apparent improvement in the signal-to-noise ration to a significant and useful degree; however the leading edge of each character is somewhat attenuated, with the amount of attenuation decreasing over several dots worth for each character. During the space between characters and words the attenuation is reset so that it starts all over on the next character. The effect is to make the first few elements of each character hard to pick up, though later elements are nice and clear. Put simply, the NR gives a mushy effect to the code (at about 20-25 wpm). I suppose this is a function of the DSP training itself to find the best possible S/N ratio in a relatively short time. If this training could be remembered just a little longer so that it remained constant for a train of words, it would be much more useful. Haven't tried it at higher speeds since the nets all run at about the same speed. Just my $.02! 73, Van W1WCG - Original Message - From: WILLIS COOKE wrco...@flash.net To: elecraft@mailman.qth.net; Darwin, Keith keith.dar...@goodrich.com Sent: Monday, February 02, 2009 11:01 AM Subject: Re: [Elecraft] K3 Narrow CW Filter I have not found NR to be useful for CW reception. It distorts the signal even on the lowest setting and to me makes the signal harder to copy than without NR. I use 50 and 100 HZ DSP a lot and these narrow settings seem to improve the signal to noise level a lot. I just finished a lot of operation as K3Y/5 where a number of operators were having a competition to see how low they could set their power and still make a sort of contact. It gave me a lot of practice in copying ESP level signals with the other guy running well less than a watt. I have the 8 pole 250 Hz filter, but I think the DSP filter is doing the heavy lifting. So far, I have not found the NR to be useful for SSB or CW. Willis 'Cookie' Cooke K5EWJ, K3 1025 --- On Mon, 2/2/09, Darwin, Keith keith.dar...@goodrich.com wrote: From: Darwin, Keith keith.dar...@goodrich.com Subject: Re: [Elecraft] K3 Narrow CW Filter To: elecraft@mailman.qth.net Date: Monday, February 2, 2009, 7:50 AM NR in the K3 is a tool that primarily turns the volume down. Well, in all fairness, it does so selectively, turning down the noise more than the signal, but it does result in a reduction in signal even though the S/N ratio gets better. I'm thinking at 100 hz, there is so little noise for NR to process that it is easier for the signal to get treated as noise and to be attenuated. You may find you get the rig to sound better if you quit using NR and adjust the AGC slope or threshold instead. Set the AGC threshold higher and reduce the ratio a bit. This will help to generate more of a ratio between the signal and background noise. ESE - nice call by the way ! 73 - Keith N1AS - - K3 711 - -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Huffman Sent: Monday, February 02, 2009 10:05 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 Narrow CW Filter I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? Thanks in advance. 73 de K1ESE John __ 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
Re: [Elecraft] K3 Narrow CW Filter
John Huffman-3 wrote: My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? NR is actually not doing much to improve S/N at low BW settings. The same was true for Orion (which I used for 4 years). While NR might be useful at SSB bandwidths, it's probably just fooling you at narrow CW bandwidths. Read from the horse's mouth below and especially note #6. 73, Bill http://www.zerobeat.net/mediawiki/index.php/K3_DSP NR explained by Lyle Johnson KK7P I think there is a fundamental misunderstanding of what NR is and how it works, at least in the context of the K3. 1) NR is better named SE (signal enhancer). 2) It is a short FIR filter whose coefficients are continuously being recalculated. 3) It defaults to suppressing everything. 4) When it senses that there is something that correlates (i.e., has a pattern that doesn't seem to be entirely random), it attempts to build a filter around those frequencies that seem less random. 5) Because the FIR filter that is being implemented is short, the filter being built is less selective than the normal DSP filters in the radio. 6) NR is rarely useful if the bandwidth is narrow. If you set your CW width to 400 Hz or less, for example, there is no point in running NR *unless* you want to use it as a sort-of smart squelch. 7) The narrower you set your WIDTH, the more that noise appears like a signal, and the worse the NR will perform. And the less noise there is anyway, assuming there is a signal present. NR cannot compete with a narrow filter, and was not designed to. 8) I find NR most useful during CW operation with the 2.8 kHz roofing filter NORM'ed so the Rx bandwidth is wide. Assuming band activity is low, the Rx is quiet. If a CW station comes on within the Rx passband, a filter will be built around the station and I can hear it. 9) Similarly, I find NR in SSB is mostly useful as a sort of squelch when tuning around, or monitoring a frequency you are expecting a call on (probably a net or a sked). I use NR1-1 or NR1-2 for this. Mild suppression, not too much impact on fidelity, and lets me hear weak signals, too. I hope this is helpful in better understanding how NR is implemented in the K3. -- View this message in context: http://n2.nabble.com/K3-Narrow-CW-Filter-tp2258338p2258733.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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 Narrow CW Filter
John Huffman-3 wrote: I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? In the config menu, turn on the AF LIM (start with a setting of 15-20 and adjust to your ears) and turn off AGC. You may also want to narrow down the cw bandwidth. This will deliver the effect you are looking for. 73, Barry N1EU -- View this message in context: http://n2.nabble.com/K3-Narrow-CW-Filter-tp2258338p2258918.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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 Narrow CW Filter
Thanks to all for the replies. Stewart identified the problem. It was self-inflicted. I had set the RX EQ to optimize the CW shift frequency and retard all other frequencies. Undoing that solved the problem. Thanks!! As for DSP and narrow CW bandwidths, it is the smart squelch that I am trying to achieve. I know most Orion owners complain about the NR, but for me the NR in the current Orion firmware does exactly what I wanted. The best NR I have ever heard (my opinion) was my Omni 6+. The NR removed the background noise AND peaked the CW signal. Signals jumped out of the noise. 73 de K1ESE John GW0ETF wrote: John Huffman-3 wrote: I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. John, I had the following from Vic K2VCO in response to a post by me about Noise Reduction and RX Equalisation settings - I had it boosted at the cw sidetone frequency to give an accentuated effect with NR but found my audio dropped when I reduced the b/w beyond the 150 Hz point. So you may want to check/play with your RX Eq settings This is not the best approach because of the following: when the 50 and 100 Hz DSP filters are enabled the RX EQ is disabled (I forgot the reason for this, but Lyle explained it to me). So the effect of narrowing the bandwidth is that the signal suddenly drops several dB! If you want to use the RX EQ for this the best way to do it is to leave the desired bands at 0 dB and *reduce* all others by the amount of 'boost' that you prefer. __ 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 Narrow CW Filter
I have not found NR to be useful for CW reception. It distorts the signal even on the lowest setting and to me makes the signal harder to copy than without NR. I use 50 and 100 HZ DSP a lot and these narrow settings seem to improve the signal to noise level a lot. I just finished a lot of operation as K3Y/5 where a number of operators were having a competition to see how low they could set their power and still make a sort of contact. It gave me a lot of practice in copying ESP level signals with the other guy running well less than a watt. I have the 8 pole 250 Hz filter, but I think the DSP filter is doing the heavy lifting. So far, I have not found the NR to be useful for SSB or CW. Willis 'Cookie' Cooke K5EWJ, K3 1025 --- On Mon, 2/2/09, Darwin, Keith keith.dar...@goodrich.com wrote: From: Darwin, Keith keith.dar...@goodrich.com Subject: Re: [Elecraft] K3 Narrow CW Filter To: elecraft@mailman.qth.net Date: Monday, February 2, 2009, 7:50 AM NR in the K3 is a tool that primarily turns the volume down. Well, in all fairness, it does so selectively, turning down the noise more than the signal, but it does result in a reduction in signal even though the S/N ratio gets better. I'm thinking at 100 hz, there is so little noise for NR to process that it is easier for the signal to get treated as noise and to be attenuated. You may find you get the rig to sound better if you quit using NR and adjust the AGC slope or threshold instead. Set the AGC threshold higher and reduce the ratio a bit. This will help to generate more of a ratio between the signal and background noise. ESE - nice call by the way ! 73 - Keith N1AS - - K3 711 - -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Huffman Sent: Monday, February 02, 2009 10:05 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 Narrow CW Filter I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? Thanks in advance. 73 de K1ESE John __ 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 Narrow CW Filter
NR in the K3 is a tool that primarily turns the volume down. Well, in all fairness, it does so selectively, turning down the noise more than the signal, but it does result in a reduction in signal even though the S/N ratio gets better. I'm thinking at 100 hz, there is so little noise for NR to process that it is easier for the signal to get treated as noise and to be attenuated. You may find you get the rig to sound better if you quit using NR and adjust the AGC slope or threshold instead. Set the AGC threshold higher and reduce the ratio a bit. This will help to generate more of a ratio between the signal and background noise. ESE - nice call by the way ! 73 - Keith N1AS - - K3 711 - -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Huffman Sent: Monday, February 02, 2009 10:05 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 Narrow CW Filter I'm getting used to my new K3, but have a question. My K3 has the 400hz 8-pole filter and the latest firmware. I've noticed that the difference between running the DSP filter at 100hz and 150hz is greatly increased volume at 150hz. With the NR on (F2-4) easy listening at 100hz will bow your ears out at 150hz. Is this just me? I run AF gain at 9 o'clock and RF gain at 12 o'clock. I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? Thanks in advance. 73 de K1ESE John __ 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 Narrow CW Filter
Barry - That works really well!! Thanks... 73 de K1ESE John Barry N1EU wrote: John Huffman-3 wrote: I have a second question. I liked to run my Orion on CW with the AF gain up, RF gain down, narrow filter and NR on. That way it listening to the other station was like listening to a code practice oscillator. On the K3 I still get background hiss with the noise reduction on. Are there better settings to use to get the sound I want with no background noise? In the config menu, turn on the AF LIM (start with a setting of 15-20 and adjust to your ears) and turn off AGC. You may also want to narrow down the cw bandwidth. This will deliver the effect you are looking for. 73, Barry N1EU __ 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
