Re k3 receive audio
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I've got a 3month old k3. I was impressed with how full bodied or maybe even hi fidelity some of the audio sounded but I eventually grew tired of how the background band noise sounded in my rural QTH. The best I can describe is it had a high edge to it. I eventually went to a vacant frequency and adjusted the equalizer to get the noise to sound more natural to "my" liking. That was fine but the signal audio was now kind of plain or dull or monotone, no more full rich sound.
I've since discovered that narrowing the bandwidth to 2.4 removes a lot of noise so I'm currently trying that and have changed the equalizer to a more neutral setting. I think I'm liking that better. I like to use width and shift. I like to know where their at but I know a lot of Operators prefer hi/lo cut on ssb. I'll soon try that as well and hopefully find That full audio with non irritating noise. 73 Mike R Sent from my spy ring ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Mike,
It might be the default AGC settings that you are struggling with. If your K3 sounds "noisy" between stations, or between pauses in the other station's transmissions, then I suggest that the AGC Threshold and Slope settings may not be right for your situation. Please review the "Noisy K3" article on my website for additional information and a guide to choosing your own AGC menu settings. 73, Don W3FPR On 4/10/2011 9:00 PM, Mike Rodgers wrote: > I've got a 3month old k3. I was impressed with how full bodied or maybe even hi fidelity some of the audio sounded but I eventually grew tired of how the background band noise sounded in my rural QTH. The best I can describe is it had a high edge to it. I eventually went to a vacant frequency and adjusted the equalizer to get the noise to sound more natural to "my" liking. That was fine but the signal audio was now kind of plain or dull or monotone, no more full rich sound. > I've since discovered that narrowing the bandwidth to 2.4 removes a lot of noise so I'm currently trying that and have changed the equalizer to a more neutral setting. I think I'm liking that better. > I like to use width and shift. I like to know where their at but I know a lot of > Operators prefer hi/lo cut on ssb. I'll soon try that as well and hopefully find > That full audio with non irritating noise. > > 73 > Mike R > > Sent from my spy ring > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Mike,
Don W3FPR has a great article about setting your AGC. Another website I have found very helpfull is this one: http://www.cliftonlaboratories.com/elecraft_k2_and_k3_transceivers.htm I had the same problems you have but now I'm very pleased with my K3 ;-) Best 73, Maarten PD2R 2011/4/11, Don Wilhelm <[hidden email]>: > Mike, > > It might be the default AGC settings that you are struggling with. If > your K3 sounds "noisy" between stations, or between pauses in the other > station's transmissions, then I suggest that the AGC Threshold and Slope > settings may not be right for your situation. > > Please review the "Noisy K3" article on my website for additional > information and a guide to choosing your own AGC menu settings. > > 73, > Don W3FPR > > On 4/10/2011 9:00 PM, Mike Rodgers wrote: >> I've got a 3month old k3. I was impressed with how full bodied or maybe >> even hi fidelity some of the audio sounded but I eventually grew tired of >> how the background band noise sounded in my rural QTH. The best I can >> describe is it had a high edge to it. I eventually went to a vacant >> frequency and adjusted the equalizer to get the noise to sound more >> natural to "my" liking. That was fine but the signal audio was now kind of >> plain or dull or monotone, no more full rich sound. >> I've since discovered that narrowing the bandwidth to 2.4 removes a lot of >> noise so I'm currently trying that and have changed the equalizer to a >> more neutral setting. I think I'm liking that better. >> I like to use width and shift. I like to know where their at but I know a >> lot of >> Operators prefer hi/lo cut on ssb. I'll soon try that as well and >> hopefully find >> That full audio with non irritating noise. >> >> 73 >> Mike R >> >> Sent from my spy ring >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > -- Best 73, Maarten PD2R ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Maarten, PD2R Member of the PI4DX contest group www.pi4dx.com Elecraft K3 nr:1849 |
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I set both of my K3s up based on Don's recommendations and found them to be very helpful. Tom N5GE On Mon, 11 Apr 2011 09:40:41 +0200, Maarten van Rossum <[hidden email]> wrote: >Mike, > >Don W3FPR has a great article about setting your AGC. Another website >I have found very helpfull is this one: >http://www.cliftonlaboratories.com/elecraft_k2_and_k3_transceivers.htm > >I had the same problems you have but now I'm very pleased with my K3 ;-) > >Best 73, > >Maarten >PD2R > >2011/4/11, Don Wilhelm <[hidden email]>: >> Mike, >> >> It might be the default AGC settings that you are struggling with. If >> your K3 sounds "noisy" between stations, or between pauses in the other >> station's transmissions, then I suggest that the AGC Threshold and Slope >> settings may not be right for your situation. >> >> Please review the "Noisy K3" article on my website for additional >> information and a guide to choosing your own AGC menu settings. >> >> 73, >> Don W3FPR >> >> On 4/10/2011 9:00 PM, Mike Rodgers wrote: >>> I've got a 3month old k3. I was impressed with how full bodied or maybe >>> even hi fidelity some of the audio sounded but I eventually grew tired of >>> how the background band noise sounded in my rural QTH. The best I can >>> describe is it had a high edge to it. I eventually went to a vacant >>> frequency and adjusted the equalizer to get the noise to sound more >>> natural to "my" liking. That was fine but the signal audio was now kind of >>> plain or dull or monotone, no more full rich sound. >>> I've since discovered that narrowing the bandwidth to 2.4 removes a lot of >>> noise so I'm currently trying that and have changed the equalizer to a >>> more neutral setting. I think I'm liking that better. >>> I like to use width and shift. I like to know where their at but I know a >>> lot of >>> Operators prefer hi/lo cut on ssb. I'll soon try that as well and >>> hopefully find >>> That full audio with non irritating noise. >>> >>> 73 >>> Mike R >>> >>> Sent from my spy ring >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[hidden email] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Amateur Radio Operator N5GE
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In reply to this post by mikerodgerske5gbc
Recently Don Wilhelm posted a K3 fix for noisy audio, I tried it and it
works very well. This fix solved a noisy audio problem I have had for over a year. I'm an old timer, 88, and the K3 is a young transceiver took a while getting together. I don't do digital modes or contests just sideband with old friends. The noise between transmissions was like Niagara Falls but not any more. If you are having the same dull roar pull up www.w3fpr.com and fix it. 73 Bob,w5pvr ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Turn down the RF Gain. It really is that simple. 73, Barry N1EU |
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Yes, it certainly IS that simple.
I remember the old radios well. They never had the "problem". They didn't have enough gain to have the "problem". Nor was it possible to have the AGC recover in such a short interval that the noise sounded as if it were the same level as the desired signal, even if many S units weaker. Using RC timing only and a single voltage bus, really fast AGC produces really obvious distortion. So why have digital methodology that can produce setting combinations that produce roar-in-your-ear behavior? Very simple. People wanted the options and to be able to set it just like they wanted it, so the available ranges of AGC constants were set to allow people to set it to taste. If you go back and read the archives, people were pretty sharp-tongued about having all the options. But whether consciously or not, many (most?) people were EXPECTING the K3 to sound like Pappy's analog radio, and divergences were reported as K3 "troubles", and still are. AND, as it has always been on the old radios, once AGC was on the scene, the only setting used for RF gain was wide open. And wide open is now 30 db farther down than Pappy's old analog radio, AND can do all that without distortion. Someone was asked why he was running RF gain at max and PRE on on 80 meters. He thought about it a while and said he guessed because he always had. And sure enough, looking at a now idled older Yakencom rig, that's how it was. Turned it on and the older rig *NEEDED* the PRE on 75 meters for morning SSB. And right beside that was an old Ameco preamp to put in front of the radio's built-in preamp if you wanted to hear anything weak on 15 and 10 meters. RF gain maxxed out is just habit and we are taking some time getting used to stuff that doesn't act like the old radios. On my K3 on 80 and 160 I use the attenuator on and the preamp off when listening to the transmit antenna. I have an on-the-ground loop array listening antenna, and when listening to that have ATT off and PRE on. The 20+ dB difference between ATT on and PRE on almost makes up for the RX antenna's normal very low gain. If I flip the RX source with the RX front panel button, the K3 seamlessly switches the ATT and PRE in and out. Very nice, very handy. It also makes for stellar diversity because the same trick is available for the second RX. That very useful convenience being in play for anyone who buys a K3, means that everyone has to understand PRE needs to be OFF and ATT ON for 80 and 160 listening on transmitting antennas, and adjust accordingly. Fail to do that, and somebody has a K3 noise "problem". But the fix is between the ears, not in the K3. SETTINGS, which is what we are really talking about, are the user's problem. I'm watching my incoming noise tonight on 160. S5 between strike QRN, with that up to 20, 30 or 40 over. That's something like -100 dBm steady. -100 dBm just tickles the S-meter on my MP. On the K3's S-meter, where calibrated S units ACTUALLY ARE six dB per step, S0 actually *IS* 54 dB below S9, which actually IS -73 dBm. So, watching both of them, the K3 is five S units noisier than the MP, or that's how it gets reported -- "my K3 is terribly noisy on 160 and 80". Add to that the maxxed out RF gain, plus PRE turned on, plus unfortunate user-chosen ACG settings and the user expecting it to act like old analog radios, and not understanding the differences, we have one unhappy owner. My MP's S meter is a liar. What was really going on was that the AGC and the signal measurement ARE THE SAME CIRCUIT, as they have been in all the old radios. The truth of the matter is that S0 (no deflection) is 54 dB below 50 microvolts across 50 ohms or -73 dBm. So S0 is -127 dBm. Our old radios had NO chance of AGC engaging at -127. A lot could not even HEAR -127. So the S-unit scale was a lie TO BEGIN WITH. What radio manufacturer is going to tell the truth and start his S-unit scale at S5? Now you have explained the MP's compression of S-units into 20 to 25 dB. And what manufacturer is going to take the AGC bus and show how cramped the range is on top, and put S9 to 40 over in the right 1/6th of the scale? So on the old radios you have a meter that doesn't show you much more than one signal is louder than another. Calibrated K3 tells the truth. The firmware program analyzes multiple states in the radio, and runs it through a calibration table to compute the actual signal strength. Personally, I wish there was a way to have the K3 (by itself) read out in dBm at the antenna. The K3 ain't your daddy's analog radio, however much we are unconsciously looking for that. But once you learn and get used to the new stuff, you'll never wanna go back. No way. 73, Guy. On Tue, Apr 12, 2011 at 6:45 PM, Barry N1EU <[hidden email]> wrote: > > Bob,w5pvr wrote: >> >> The noise between transmissions was like Niagara Falls but not >> any more. >> > Turn down the RF Gain. Â It really is that simple. > > 73, Barry N1EU > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Guy,
Again your ability to write down what is REAL and what is NOT is again 'right on the money'. This last post of yours should be REQUIRED reading by all new owners of the K3 to help them better understand the radio, the design and the capabilities. Maybe even a version of your explanation should be included in the K3 manual or at the very least be included in a 'TUTORIAL' available to all on the Elecraft website. Thankyou. Gary On 14 April 2011 02:08, Guy Olinger K2AV <[hidden email]> wrote: > Yes, it certainly IS that simple. > > I remember the old radios well. They never had the "problem". They > didn't have enough gain to have the "problem". Nor was it possible to > have the AGC recover in such a short interval that the noise sounded > as if it were the same level as the desired signal, even if many S > units weaker. Using RC timing only and a single voltage bus, really > fast AGC produces really obvious distortion. > > So why have digital methodology that can produce setting combinations > that produce roar-in-your-ear behavior? Very simple. People wanted > the options and to be able to set it just like they wanted it, so the > available ranges of AGC constants were set to allow people to set it > to taste. If you go back and read the archives, people were pretty > sharp-tongued about having all the options. > > But whether consciously or not, many (most?) people were EXPECTING the > K3 to sound like Pappy's analog radio, and divergences were reported > as K3 "troubles", and still are. AND, as it has always been on the > old radios, once AGC was on the scene, the only setting used for RF > gain was wide open. > > And wide open is now 30 db farther down than Pappy's old analog radio, > AND can do all that without distortion. Someone was asked why he was > running RF gain at max and PRE on on 80 meters. He thought about it a > while and said he guessed because he always had. And sure enough, > looking at a now idled older Yakencom rig, that's how it was. Turned > it on and the older rig *NEEDED* the PRE on 75 meters for morning SSB. > And right beside that was an old Ameco preamp to put in front of the > radio's built-in preamp if you wanted to hear anything weak on 15 and > 10 meters. > > RF gain maxxed out is just habit and we are taking some time getting > used to stuff that doesn't act like the old radios. > > On my K3 on 80 and 160 I use the attenuator on and the preamp off when > listening to the transmit antenna. I have an on-the-ground loop array > listening antenna, and when listening to that have ATT off and PRE on. > The 20+ dB difference between ATT on and PRE on almost makes up for > the RX antenna's normal very low gain. If I flip the RX source with > the RX front panel button, the K3 seamlessly switches the ATT and PRE > in and out. Very nice, very handy. It also makes for stellar > diversity because the same trick is available for the second RX. > > That very useful convenience being in play for anyone who buys a K3, > means that everyone has to understand PRE needs to be OFF and ATT ON > for 80 and 160 listening on transmitting antennas, and adjust > accordingly. > > Fail to do that, and somebody has a K3 noise "problem". > > But the fix is between the ears, not in the K3. SETTINGS, which is > what we are really talking about, are the user's problem. > > I'm watching my incoming noise tonight on 160. S5 between strike QRN, > with that up to 20, 30 or 40 over. That's something like -100 dBm > steady. -100 dBm just tickles the S-meter on my MP. On the K3's > S-meter, where calibrated S units ACTUALLY ARE six dB per step, S0 > actually *IS* 54 dB below S9, which actually IS -73 dBm. So, watching > both of them, the K3 is five S units noisier than the MP, or that's > how it gets reported -- "my K3 is terribly noisy on 160 and 80". Add > to that the maxxed out RF gain, plus PRE turned on, plus unfortunate > user-chosen ACG settings and the user expecting it to act like old > analog radios, and not understanding the differences, we have one > unhappy owner. > > My MP's S meter is a liar. What was really going on was that the AGC > and the signal measurement ARE THE SAME CIRCUIT, as they have been in > all the old radios. The truth of the matter is that S0 (no > deflection) is 54 dB below 50 microvolts across 50 ohms or -73 dBm. > So S0 is -127 dBm. > > Our old radios had NO chance of AGC engaging at -127. A lot could not > even HEAR -127. So the S-unit scale was a lie TO BEGIN WITH. What > radio manufacturer is going to tell the truth and start his S-unit > scale at S5? Now you have explained the MP's compression of S-units > into 20 to 25 dB. And what manufacturer is going to take the AGC bus > and show how cramped the range is on top, and put S9 to 40 over in the > right 1/6th of the scale? So on the old radios you have a meter that > doesn't show you much more than one signal is louder than another. > > Calibrated K3 tells the truth. The firmware program analyzes multiple > states in the radio, and runs it through a calibration table to > compute the actual signal strength. Personally, I wish there was a > way to have the K3 (by itself) read out in dBm at the antenna. > > The K3 ain't your daddy's analog radio, however much we are > unconsciously looking for that. But once you learn and get used to > the new stuff, you'll never wanna go back. No way. > > 73, Guy. > > On Tue, Apr 12, 2011 at 6:45 PM, Barry N1EU <[hidden email]> wrote: > > > > Bob,w5pvr wrote: > >> > >> The noise between transmissions was like Niagara Falls but not > >> any more. > >> > > Turn down the RF Gain. It really is that simple. > > > > 73, Barry N1EU > > > 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:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > -- *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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Guy, K2AV
Guy's analysis seems to identify the key point. You can definitely get
better reception under noisy conditions by going into "SX-101 mode," turning the AF gain all the way up and riding the RF gain with your left hand. This reduces the AGC effect, possibly defeating it altogether, depending on where the RF gain is set. As Don points out, the first step is to go to the Config menu, and set slope and threshold (0 for slope and 15 for threshold minimizes the noise enhancement of AGC). When that isn't enough, you can leave AGC on and tune as described above, or turn AGC off altogether; this gives good results, but requires even more constant cranking of the RF gain. I have noise not only on 80 and 160, but often on all bands. Sometimes when using this technique I can find a setting for RF gain that is right below some sort of threshold where the noise suddenly jumps into my ears. Re-shaping the AGC in this way almost always improves the K3's signal/noise audio as I perceive it when digging for weak signals. Perhaps some manufacturer, or maybe all manufacturers, will soon figure out a way to handle this automatically. Tony KT0NY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Tony,
Why would we want manufacturers to give us a "fully auto-magical, panacea radio" that simply becomes a proverbial "Black Box" that we simply turn on and speak or operate in other modes? Elecraft are leading the way I feel in giving us some serious weaponry to fight widely varying conditions. The sun spot cycle is changing, so are signals we are receiving. I personally enjoy being able to dig that low down in the noise signal I hear with the K3. Something I am unable to do with the other radios I have had and used with the same antenna systems I have now. History shows us that manufacturers have tried the "fully automatic" approach and have now shied away from that by offering more knobs and buttons, FW selections and "tweekability" in their current products than ever before. Maybe, just maybe, a fully automatic design radio will only give us limited ability to override the receiver and create just another set of radios that perform worse than the current crop on the market. I want the choices I have now and I am happy with the K3 development to date. YMMV Gary On 14 April 2011 08:50, Tony Estep <[hidden email]> wrote: > Guy's analysis seems to identify the key point. You can definitely get > better reception under noisy conditions by going into "SX-101 mode," > turning > the AF gain all the way up and riding the RF gain with your left hand. This > reduces the AGC effect, possibly defeating it altogether, depending on > where > the RF gain is set. > > As Don points out, the first step is to go to the Config menu, and set > slope > and threshold (0 for slope and 15 for threshold minimizes the noise > enhancement of AGC). When that isn't enough, you can leave AGC on and tune > as described above, or turn AGC off altogether; this gives good results, > but > requires even more constant cranking of the RF gain. > > I have noise not only on 80 and 160, but often on all bands. Sometimes when > using this technique I can find a setting for RF gain that is right below > some sort of threshold where the noise suddenly jumps into my ears. > Re-shaping the AGC in this way almost always improves the K3's signal/noise > audio as I perceive it when digging for weak signals. > > Perhaps some manufacturer, or maybe all manufacturers, will soon figure out > a way to handle this automatically. > > Tony KT0NY > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > -- *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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Does the KPA-500 require the pull-up resistor mod installed on the K3
digital I/O board? THX & 73, Bill N2BC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Gary Gregory
I have the 5 pole 2.7 filters for main and sub RX.
One filter offset is -.94, the other is -.81 In order to do diversity receive, I have to set them both to about -.88 My question is: what happens when you set a filter offset differently than the one specified (as in my case) ? How is this supposed to influence operation (normal as well as diversity mode) ? How can things be improved, short of buying new filters? Thank you, Adi 2E0TTX ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Tony Estep
Not necessarily - if you have a low ambient audio noise floor (isolating headphones, quiet room, etc) then you can have a wide audio dynamic range without "constant cranking of the RF gain". Several of us have been evangelists for this for quite some time and you can search archives/Web for more info. IMHO, listening to a single signal or tuning the band with a wide audio dynamic range is a much more enjoyable listening experience. 73, Barry N1EU |
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>
out, it seems that the way to attack the perceived degradation
> ... constant cranking of the RF gain. > > > Not necessarily - if you have a low ambient audio noise floor (isolating > headphones, quiet room, etc) then you can have a wide audio dynamic range > without "constant cranking of the RF gain". > > Several of us have been evangelists for this for quite some time and you > can > search archives/Web for more info. IMHO, listening to a single signal or > tuning the band with a wide audio dynamic range is a much more enjoyable > listening experience. > > 73, Barry N1EU > > Well, I wouldn't dispute that, Barry. In any event, as Guy and Don point of signal/noise is to minimize the effects of the K3's AGC, and/or to turn it off entirely. Tony KT0NY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by aandrei
By offsetting the 2.7Khz filter center freq, you may incur some slight asymmetry in the passband response at the lower and/or upper knee of the response curve, but the vast majority of the passband will be unaffected. If noticeable, it will be relatively minor. The other options would be to use closer matched 5-pole filters or use 8-pole filters. 73, Barry N1EU |
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In reply to this post by aandrei
Adi,
How much you can "fool" the offset depends on the filter bandwidth. 70 Hz is a small percentage (2.6%) of a 2.7 kHz bandwdth - you will hardly notice the difference, and if you do, you have very good ears, or are using instruments to measure it - most of us simply use our ears for SSB. For a 400 Hz filter width, 70 Hz makes a big difference (17,5%), so if you want to operate diversity mode with narrow CW filters, it is best that you have them matched or use only the 8 pole filters. 73, Don W3FPR On 4/13/2011 8:07 PM, Adi Andrei wrote: > I have the 5 pole 2.7 filters for main and sub RX. > One filter offset is -.94, the other is -.81 > In order to do diversity receive, I have to set them both to about -.88 > > My question is: what happens when you set a filter offset differently than the one specified (as in my case) ? > How is this supposed to influence operation (normal as well as diversity mode) ? > How can things be improved, short of buying new filters? > > Thank you, > > Adi > 2E0TTX > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Barry N1EU
test From: Barry N1EU [via
Elecraft] [mailto:[hidden email]]
By offsetting the 2.7Khz
filter center freq, you may incur some slight asymmetry in the passband
response at the lower and/or upper knee of the response curve, but the vast
majority of the passband will be unaffected. If noticeable, it will be
relatively minor. The other options would be to use closer matched 5-pole
filters or use 8-pole filters. If
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I tested, as far as I could use my ears, but it is difficult to be sure ( especially being in Londodn, UK, and having S5-S9 noise on all usable bands), I was hoping someone has tried a similar thing, or someone at Elecraft can explain what is happening in such a situation in the radio.
E.g. what kind of difference should I look for ? Is it the signal itself altered (and how), or just the passband i.e. some frequencies missing at the end of the passband. In this case, if I set the offset on .88 in and specify the filters as having 2.6 khz width (instead of 2.7), would then the radio behave as that was true, i.e. no different from the configuration I specified, although it is not the true configuration? Or would it be better to leave it at 2.7 ? In any case, thank you everyone for the answers you sent so far, Adi 2E0TTX On 14/04/2011 02:14, pcbyrne wrote: > test > > > > _____ > > From: Barry N1EU [via Elecraft] > [mailto:[hidden email]] > Sent: Wednesday, April 13, 2011 7:19 PM > To: pcbyrne > Subject: Re: K3 filter question > > > > aandrei wrote: > > I have the 5 pole 2.7 filters for main and sub RX. > One filter offset is -.94, the other is -.81 > In order to do diversity receive, I have to set them both to about -.88 > > My question is: what happens when you set a filter offset differently than > the one specified (as in my case) ? > How is this supposed to influence operation (normal as well as diversity > mode) ? > How can things be improved, short of buying new filters? > > By offsetting the 2.7Khz filter center freq, you may incur some slight > asymmetry in the passband response at the lower and/or upper knee of the > response curve, but the vast majority of the passband will be unaffected. > If noticeable, it will be relatively minor. The other options would be to > use closer matched 5-pole filters or use 8-pole filters. > > 73, Barry N1EU > > > > _____ > > If you reply to this email, your message will be added to the discussion > below: > > http://elecraft.365791.n2.nabble.com/Re-k3-receive-audio-tp6259940p6271081.h > tml > > To start a new topic under Elecraft, email > [hidden email] > To unsubscribe from Elecraft, click > <http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubsc > ribe_by_code&node=365791&code=dzdubWRAdHdpbmxha2VzLWFyLnVzfDM2NTc5MXwxMDQyOT > EzOTY1> here. > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/Re-k3-receive-audio-tp6259940p6271190.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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Definitely leave it at 2.7! I believe the firmware looks for either 2.7 (5-pole BW) or 2.8 (8-pole BW) for the TX filter so you might not be able to transmit with 2.6 selected. As Don W3FPR already stated, it is extremely unlikely most people could tell the difference with the filters offset by 70 Hz at the edge of the passband. (Standing by for the audiophile rebuttals now...) 73, Bill |
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In reply to this post by mikerodgerske5gbc
This is in response mostly to Guy,K2AV's post. I am ashamed to say that I
really didn't know better . Not having much experience with HF equipment I just assumed that it was meant to be really noisy and just lived with it. :) Of course this really annoys those around me so it tended to limit the time that I could enjoy the radio without headphones. Not to mention my aching ears after a 30 minutes under the headphones :) Thanks to your explanation and suggestions Guy you have increased my enjoyment of the K3 1000 percent and made me REALLY appreciate the difference in performance between my FT-897 and K3. The K3 is truly an amazing radio. I have had mine for almost a year now and I continue to be happily surprised by it. Now if I could only find a K3 equivalent on the VHF/UHF bands. I know, transverters are the preferred path for weak signal work. But I would still prefer a dedicated high performance radio for the VHF/UHF bands as it would better suited in general as an IF platform then an HF rig. Until then I have invested in an XV222 and Kenwood TR-751a. I will probably end up purchasing another K3 for use as a dedicated transverter platform to launch myself up into the microwave bands especially now that the K3XREF will be available soon.. In any case I would like to give my thanks to Guy and all the others on this list that are patient enough to provide meaningful explanations about why things work the way they do. I also want to give my ongoing thanks to all those at Elecraft that continue to provide some of the best equipment and customer service available at any price... -- Thanks Jon KG6VDW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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