Bigger K3 S-meter
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Hi,
Adding a new command for a dBm report would not break any existing software. A resolution of 1 S unit or 5dB is really unsatisfactory.
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Hi We might as well cover all bases and have a DBuv scale. Most professional test receivers today use a Dbuv signal strength scale. 73 Craig VK3HE --- On Fri, 10/31/08, ab2tc <[hidden email]> wrote: > From: ab2tc <[hidden email]> > Subject: Re: [Elecraft] Bigger K3 S-meter > To: [hidden email] > Date: Friday, October 31, 2008, 8:01 AM > Hi, > > Adding a new command for a dBm report would not break any > existing software. > A resolution of 1 S unit or 5dB is really unsatisfactory. > > > > Jan Erik Holm wrote: > > > > Yes dBm, I would like that. > > > > / Jim SM2EKM > > ----------------- > > Julian, G4ILO wrote: > >> > >> Jan Erik Holm wrote: > >>> Can this be changed? > >>> > >> It would break all existing software if it was. > >> > >>snip > > > > > > > ----- > AB2TC - Knut > -- > View this message in context: > http://n2.nabble.com/Bigger-K3-S-meter-tp1399030p1402802.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by ab2tc
Changing the functionality of the BG or SM commands so they could provide greater resolution *would* break software, which is what I was saying. But while I can see that having software access to the dBm reading could be useful for antenna measurement purposes, given the vagaries of propagation I would have thought that a 1 S-unit resolution was perfectly adequate for normal purposes. I cannot see how it would be more useful to be told I am S6.5 rather than S6 or S7, or even S5 or S8! Whatever the reading is it is going to be different 20 seconds later anyway.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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I would just like to see signal strength, including noise, in absolute reference levels. In particular when listening to a local while turning a beam kind of thing. Although that can be done relatively with the audio voltage level, it wouldn't allow me to tell a local that his ground wave signal has gone down 3 db and is staying there, or be able to create data for studies over time.
Since it is an SDW, such is possible. dBuv is fine. Might need linearity points as part of the package which could be calibrated with a precision attenuator. Changing the functionality of the BG or SM commands so they could provide greater resolution *would* break software, which is what I was saying. But while I can see that having software access to the dBm reading could be useful for antenna measurement purposes, given the vagaries of propagation I would have thought that a 1 S-unit resolution was perfectly adequate for normal purposes. I cannot see how it would be more useful to be told I am S6.5 rather than S6 or S7, or even S5 or S8! Whatever the reading is it is going to be different 20 seconds later anyway. |
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Hi Guy It seems that the consensus is that a pretty innacurate S-meter is ok. I dont know why everything related to ham radio has to be reduced to the bare minimum or be in the totally useless category. Not everyone's ham radio life revolves around giving out cookie cutter signal reports. Most people would not buy any piece of test equipment with 300% inaccuracy. I could just imagine all the shouting if power meters had a tolerance of +- 200% or likewise VSWR meter. S meters should be no different. A calibrated S meter could be useful tool in many other ways. - Measuring field strength and patterns of antennas. - Reporting on things like BPL and other radiated and conducted measurements that seem to be a daily threat on HF. Just knowing they close to S9 plus plus minus 20 db is not a professional way to build an argument against such pollution in professional circles. Having a calibrated S meter and adding something a like calibrated loop with a known antenna factor would make collecting and surveying potential RF pollution data very easy. While we don't need 0.1 db accuracy 1 db of accuracy is easily achieved in SDR radios. http://www.vk1od.net/bpl/QueanbeyanBplTrial2.htm - Using a good S-meter would also be a reliable way of surveying a potential new QTH. The data could be used to compare signal noise levels to the thermal noise floor, or even compare what you are measuring to the surveyed ITU noise levels on HF. It would be nice knowing that your potential new QTH is in a QRM silent location. It would also be good comparing noise floors amongst hams for various locations. - It would also be useful knowing how accurate and reliable propagation programs are on a daily basis since they do predict signal levels. This might come in handy if one wanted to build a DSP based DF system which relies on ionospheric data. - As a general level meter around the shack, it could even be used as an accurate power meter. So to me a well calibrated S-meter can take the place of many expensive instruments that most hams dont have access to on a daily basis. It is a very useful tool. When we use some sort of absolute reference our understanding of what we are measuring on a daily basis increases our understanding of what we are doing in our hobby. While we on this subject if further work is carried out on the K3's s-meter you might as well follow the IARU's recommendation for S-meters and make it quasi peak in nature. Besides these days, with the competition increasing in the new radio market with radios like the Perseus, ADAT and the newly released cheap Flexradio models, all which offer a very accurate S-meters as a feature. It would do no harm to the K3's reputation having a feature that some consider desirable, that's marketing not rocket science. 73 Craig --- On Fri, 10/31/08, Guy, K2AV <[hidden email]> wrote: > From: Guy, K2AV <[hidden email]> > Subject: Re: [Elecraft] Bigger K3 S-meter > To: [hidden email] > Date: Friday, October 31, 2008, 12:05 PM > I would just like to see signal strength, including noise, > in absolute > reference levels. In particular when listening to a local > while turning a > beam kind of thing. Although that can be done relatively > with the audio > voltage level, it wouldn't allow me to tell a local > that his ground wave > signal has gone down 3 db and is staying there, or be able > to create data > for studies over time. > > Since it is an SDW, such is possible. dBuv is fine. Might > need linearity > points as part of the package which could be calibrated > with a precision > attenuator. > > > Changing the functionality of the BG or SM commands so they > could provide > greater resolution *would* break software, which is what I > was saying. But > while I can see that having software access to the dBm > reading could be > useful for antenna measurement purposes, given the vagaries > of propagation I > would have thought that a 1 S-unit resolution was perfectly > adequate for > normal purposes. I cannot see how it would be more useful > to be told I am > S6.5 rather than S6 or S7, or even S5 or S8! Whatever the > reading is it is > going to be different 20 seconds later anyway. > > > -- > View this message in context: > http://n2.nabble.com/Bigger-K3-S-meter-tp1399030p1437492.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Well said Craig!
I would again mention how useful a nuanced S-meter is for peaking a beam heading. I am not in the habit of looking up stations on QRZ when I work them or hear them (even though I have a fast PC with dual displays right at the operating position), so unless they have a dx prefix I really don't know the proper beam heading. Typically with normal qsb I can get close enough by swinging the beam past the desired direction a few times, IF I have a nuanced and easy to read S-meter. Also, a nuanced S-meter is an invaluable sensory input that gives us subtle clues as to what is happening with propagation, and we all want to have a better sense of that, I believe. Erik K7TV
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Several people have mentioned the possible use of a nuanced S-meter or a dBm or dBuV readout as a potential serious piece of test equipment (as opposed to the quick-glance uses that I have mentioned).
In general I think receivers in the past have been unsuitable for such use because of temperature dependencies and other changes over time. Perhaps the K3, relying less on analog amplifiers, has a better potential for such use. If that is the case, it would really be a shame if that potential were not to be realized. Erik K7TV <quote author="K7TV"> Well said Craig! I |
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In reply to this post by Craig-89
If you want a test instrument, purchase a test instrument and don't load up the cost of the K3 for all of the other users. The K3 S-meter is one of the most accurate and linear meters of any transceiver - particularly if the K3 Smeter is configured for absolute mode. Resolution better than 5/6 dB per step is better left to an SDR solution like SDR-IQ or LP-PAN. > Most people would not buy any piece of test equipment > with 300% inaccuracy. Where is the 300% inaccuracy? When calibrated according to the instructions, the K3 Smeter works out to about 4.5 dB per unit (50 uV at S9, 1 uV at S2 => 34 dB/8). That makes the maximum "offset" in the middle of a step 30% - not 300%. If you need better resolution than that - buy a spectrum analyzer. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Craig > Sent: Friday, October 31, 2008 5:08 PM > To: [hidden email] > Subject: Re: [Elecraft] Bigger K3 S-meter > > > > Hi Guy > > It seems that the consensus is that a pretty innacurate S-meter is ok. > > I dont know why everything related to ham radio has to be > reduced to the bare minimum or be in the totally useless > category. Not everyone's ham radio life revolves around > giving out cookie cutter signal reports. > > Most people would not buy any piece of test equipment with > 300% inaccuracy. I could just imagine all the shouting if > power meters had a tolerance of +- 200% or likewise VSWR > meter. S meters should be no different. > > A calibrated S meter could be useful tool in many other ways. > > - Measuring field strength and patterns of antennas. > > - Reporting on things like BPL and other radiated and > conducted measurements that seem to be a daily threat on HF. > Just knowing they close to S9 plus plus minus 20 db is not a > professional way to build an argument against such pollution > in professional circles. Having a calibrated S meter and > adding something a like calibrated loop with a known antenna > factor would make collecting and surveying potential RF > pollution data very easy. While we don't need 0.1 db accuracy > 1 db of accuracy is easily achieved in SDR radios. > > http://www.vk1od.net/bpl/QueanbeyanBplTrial2.htm > > - Using a good S-meter would also be a reliable way of > surveying a potential new QTH. The data could be used to > compare signal noise levels to the thermal noise floor, or > even compare what you are measuring to the surveyed ITU noise > levels on HF. It would be nice knowing that your potential > new QTH is in a QRM silent location. It would also be good > comparing noise floors amongst hams for various locations. > > - It would also be useful knowing how accurate and reliable > propagation programs are on a daily basis since they do > predict signal levels. This might come in handy if one > wanted to build a DSP based DF system which relies on > ionospheric data. > > - As a general level meter around the shack, it could even be > used as an accurate power meter. > > So to me a well calibrated S-meter can take the place of > many expensive instruments that most hams dont have access to > on a daily basis. It is a very useful tool. When we use some > sort of absolute reference our understanding of what we are > measuring on a daily basis increases our understanding of > what we are doing in our hobby. > > While we on this subject if further work is carried out on > the K3's s-meter you might as well follow the IARU's > recommendation for S-meters and make it quasi peak in nature. > > Besides these days, with the competition increasing in the > new radio market with radios like the Perseus, ADAT and the > newly released cheap Flexradio models, all which offer a very > accurate S-meters as a feature. It would do no harm to the > K3's reputation having a feature that some consider > desirable, that's marketing not rocket science. > > > 73 > Craig > > --- On Fri, 10/31/08, Guy, K2AV <[hidden email]> wrote: > > > From: Guy, K2AV <[hidden email]> > > Subject: Re: [Elecraft] Bigger K3 S-meter > > To: [hidden email] > > Date: Friday, October 31, 2008, 12:05 PM > > I would just like to see signal strength, including noise, > > in absolute > > reference levels. In particular when listening to a local while > > turning a beam kind of thing. Although that can be done relatively > > with the audio > > voltage level, it wouldn't allow me to tell a local > > that his ground wave > > signal has gone down 3 db and is staying there, or be able > > to create data > > for studies over time. > > > > Since it is an SDW, such is possible. dBuv is fine. Might need > > linearity points as part of the package which could be calibrated > > with a precision > > attenuator. > > > > > > Changing the functionality of the BG or SM commands so they could > > provide greater resolution *would* break software, which is what I > > was saying. But > > while I can see that having software access to the dBm > > reading could be > > useful for antenna measurement purposes, given the vagaries > > of propagation I > > would have thought that a 1 S-unit resolution was perfectly > > adequate for > > normal purposes. I cannot see how it would be more useful > > to be told I am > > S6.5 rather than S6 or S7, or even S5 or S8! Whatever the > > reading is it is > > going to be different 20 seconds later anyway. > > > > > > -- > > View this message in context: > > http://n2.nabble.com/Bigger-K3-S-meter-tp1399030p1437492.html > > Sent from the Elecraft mailing list archive at Nabble.com. > > > > _______________________________________________ > > Elecraft mailing list > > Post to: [hidden email] > > You must be a subscriber to post to the list. > > Subscriber Info (Addr. Change, sub, unsub etc.): > > http://mailman.qth.net/mailman/listinfo/elecraft > > > > Help: http://mailman.qth.net/subscribers.htm > > Elecraft web page: http://www.elecraft.com > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Don Rasmussen
Once calibrated to an accurate reference, LP-PAN provides an extremely
accurate S-Meter in dBm, in addition to the display. +/- 2dB absolute accuracy can be obtained by using an Elecraft XG-2 mini module as the reference for calibration. The linearity is better than 1 dB over a 115dB range. This is independent of any K3 AGC settings. Larry N8LP >> > From: ab2tc <[hidden email]> >> > Subject: Re: [Elecraft] Bigger K3 S-meter >> > To: [hidden email] >> > Date: Friday, October 31, 2008, 8:01 AM >> > Hi, >> > >> > Adding a new command for a dBm report would not break any >> > existing software. >> > A resolution of 1 S unit or 5dB is really unsatisfactory. >> > >> > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Guy, K2AV
Guy, K2AV wrote:
> beam kind of thing. Although that can be done relatively with the audio > voltage level, it wouldn't allow me to tell a local that his ground wave > signal has gone down 3 db and is staying there, or be able to create data > for studies over time. You only require that both measurements be relative to the same reference, not that the absolute value of that reference be known. 3dB always represents the same ratio. -- David Woolley "The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I'd like to be able to calibrate it to 1 uV and 50 uV and know that the noise on the band is -10 or +3 dBuV and that the signal from a friend has gone down to +18 from +26 last week and previous. That requires a calibration, and while one could just use what the rig does naturally as a reference, the K3 has changing SDR code, and maintaining a calibration on a reference source sure does simplify things.
To another objection earlier in the thread, inexpensive test equipment doesn't have selectability to narrow down on a single CW signal. So I'm looking at the firmware only abilities (not hardware) of a K3 to do something that has always been a bear. Other SDR's have it, so I figure Wayne will get to it in time, and I will have a piece of on-the-air test gear that I've never had, and prior to now couldn't get without taking out a mortgage. 73, Guy.
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Guy,
I too would like that capability, *but* it would not make sense to use the K3 this way unless it has the long term gain stability (including vs. temperature changes) to support it. In response to my raising that issue, Geoff (GM4ESD) emailed me off list to suggest that the J-FET used used in the K3 signal chain before the DSP (used in the hardware AGC loop unless I am mistaken) may be a source of gain variation with temperature. On the other hand, I would think that the K3 receive gain would be more stable against temperature variations than an analog receiver that might have many more stages that are susceptible. I don't know if the K3 hardware is stable enough to be used as a calibrated uV meter. If it is, then no doubt we will eventually see software and firmware to make use of it. If not, then I would not fault Wayne, since a designer cannot please everybody, and he must design for the goals that make economic sense to him. It has been pointed out that some software defined receivers (presumably without analog stages) can function well as calibrated signal strenght meters for received signals. Personally I would want something like that anyway, for the panoramic reception capability, so that makes me less impatient for the K3 to be proven as or disproven as a precision RF voltmeter. (I would still like to have a high-resolution S-meter, though, inaccurate or not. Thanks Don Rasmussen for sharing your approach.). I have a SoftRock Lite in the pipeline for a first panadapter attempt. The price of that is so low that it isn't very important whether it is good enough or not. If it is not, I will just move on to something better. It would be interesting to know what you give up if you get, say, an SDR-IQ vs. a Perseus. Of course the LP-Pan is also an alternative. 73, Erik K7TV <quote author="Guy, K2AV"> I'd like to be able to calibrate it to 1 uV and 50 uV and know that the noise on the band is -10 or +3 dBuV and that the signal from a friend has gone down to +18 from +26 last week and previous. That requires a calibration, and while one could just use what the rig does naturally as a reference, the K3 has changing SDR code, and maintaining a calibration on a reference source sure does simplify things. To another objection earlier in the thread, inexpensive test equipment doesn't have selectability to narrow down on a single CW signal. So I'm looking at the firmware only abilities (not hardware) of a K3 to do something that has always been a bear. Other SDR's have it, so I figure Wayne will get to it in time, and I will have a piece of on-the-air test gear that I've never had, and prior to now couldn't get without taking out a mortgage. 73, Guy. |
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In reply to this post by Craig-89
Agreed
> A calibrated S meter could be useful tool in many other ways. > > - Measuring field strength and patterns of antennas. > > - Reporting on things like BPL and other radiated and conducted > measurements that seem to be a daily threat on HF. Just knowing they close > to S9 plus plus minus 20 db is not a professional way to build an > argument against such pollution in professional circles. Having a > calibrated S meter and adding something a like calibrated loop with a > known antenna factor would make collecting and surveying potential RF > pollution data very easy. While we don't need 0.1 db accuracy 1 db of > accuracy is easily achieved in SDR radios. > > http://www.vk1od.net/bpl/QueanbeyanBplTrial2.htm > > - Using a good S-meter would also be a reliable way of surveying a > potential new QTH. The data could be used to compare signal noise levels > to the thermal noise floor, or even compare what you are measuring to the > surveyed ITU noise levels on HF. It would be nice knowing that your > potential new QTH is in a QRM silent location. It would also be good > comparing noise floors amongst hams for various locations. > > - It would also be useful knowing how accurate and reliable propagation > programs are on a daily basis since they do predict signal levels. This > might come in handy if one wanted to build a DSP based DF system which > relies on ionospheric data. > > - As a general level meter around the shack, it could even be used as an > accurate power meter. > > So to me a well calibrated S-meter can take the place of many expensive > instruments that most hams dont have access to on a daily basis. It is a > very useful tool. When we use some sort of absolute reference our > understanding of what we are measuring on a daily basis increases our > understanding of what we are doing in our hobby. > > While we on this subject if further work is carried out on the K3's > s-meter you might as well follow the IARU's recommendation for S-meters > and make it quasi peak in nature. > > Besides these days, with the competition increasing in the new radio > market with radios like the Perseus, ADAT and the newly released cheap > Flexradio models, all which offer a very accurate S-meters as a feature. > It would do no harm to the K3's reputation having a feature that some > consider desirable, that's marketing not rocket science. > > > 73 > Craig > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I just came across another situation where the K3 S-meter wasn't doing the job.
Bought an MFJ noise canceller (works at receive frequency, using a separate noise pickup antenna). The reason that the purchase came about *now* was that, unlike my other rigs, the K3 has this wonderful RX antenna loop, where the noise canceller can be inserted without worries about transmitting through it. On the device you adjust an amplitude control for each antenna such that the noise signal has the same amplitude from both antennas, and then you adjust a phasing control to null out the noise signal. Well, guess, what? Both for the amplitude matching and for nulling an S-meter showing a small differences such as 1 dB is highly desirable. While this can occasionally be done for distant unwanted signals, the main usefulness of the device is for when the amplitude and phase relationships are constant, i.e. for local noise sources. Thus there is no QSB to dither the reading between full S-units - with only full S-units shown you have no idea if you are 6 dB or 1 dB from the next step. If you don't see a small decrease when approaching the null, you are likely to turn the knob too fast and miss the null altogether. My workaround was to turn off AGC and listen for the volume changes. I deemed the built-in audio level meter to be too slow. To to what almost any radio would let me do by just watching the S-meter, I had one button press to turn off the AGC, one shock to my ears, one adjustment to RF gain, one button press to turn on AGC and one readjustment of RF gain. A computer program displaying the S-meter output from the K3 is no help in this situation, as it only sees whole S-units, and with no QSB it won't bounce between those steps. A panoramic display is probably helpful, and this experience gives me another reason to get one. However, after I spent the day using the computer for other work, I usually feel to lazy to turn on ham radio software just to relax from the computer by doing some some ham radio. Also, I always do Field Day with a group that lets me bring my own radio but has no power source to power my laptop. (Logging is done using an ancient DOS FD logging program, running on a small old laptop to which I don't have access for installing panoramic software (nor any other software that might complement the functionality of the K3). 73, Erik K7TV
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Yes indeed. IMO there are two things that are pure junk on the K3,
S-meter and the 12V DC power connectors. Too bad it can´t get fixed. Also I don´t like that the VOX gain changes with mic gain level, IMO they should be independent. Like anything in life nothing is perfect. / Jim SM2EKM ------------------------- K7TV wrote: > between full S-units - with only full S-units shown you have no idea if you > are 6 dB or 1 dB from the next step. If you don't see a small decrease when > approaching the null, you are likely to turn the knob too fast and miss the > null altogether. My workaround was to turn off AGC and listen for the volume _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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