Agree completely. I find all S meters to be totally inaccurate and next to useless, including my K3S’.
> On Apr 24, 2020, at 7:43 AM, Morgan Bailey <[email protected]> wrote: > > Maybe it is just me but, Turn the radio on, adjust the audio/rf/agc > controls, hear the station, work him, move on. I dont need a fancy dbm or > an iconic number of engineering controls, to say what the dbm was when I > worked the guy. When you contest, who the hell cares, hear him, work him, > move on. In simple terms, I just want selectivity, and no agc pumping and > no front in desensing from a 40 db over nine station 2khz away. > > Im looking forward to a quiet front end, that keeps me from having to > listen to 48 hours of static that is generated by the stages with in the > radio. Love my K3S, great radio. Simple to operate once you learn its > controls and never has failed me. > > Looking forward to K4 delivery. > > Vy 73, > Morgan Bailey NJ8M > > > > On Thu, Apr 23, 2020 at 11:33 PM Al Lorona <[email protected]> wrote: > >> Now that the K4 has exact knowledge of its gains and losses through the >> preamps, attenuators, splitters, bandpass filters and so forth, could this >> enable an alternate way of visualizing the receiver's range? This alternate >> measurement would be quite useful in setting the controls optimally for any >> situation. >> >> Imagine a scale -- I suppose it would be in dBm -- showing the K4's total >> dynamic range. Say it's 100 dB in total. The lowest point is the minimum >> discernable signal (MDS); the highest point is the damage level, or if >> that's a bit too frightening, call it the maximum ADC level or something >> else to denote it as a Level Not To Be Exceeded. >> >> Since the K4 will know not only what the noise floor of the band you're >> listening to is, but the absolute value of that level in dBm, the scale can >> be annotated with a dynamic marker to show where the band noise falls in >> that 100 dB range. I'm calling it 'dynamic' because it'll vary a few dB as >> band noise does, but it will sit at a calibrated level, relatively >> motionless on the scale as Wayne described the S-meter doing. >> >> As the operator kicks in more gain by turning on preamps or turning up the >> RF Gain, the scale shifts downward by the same amount. For instance, if the >> scale was showing -120 to -20 dBm -- a 100 dB range -- and then the >> operator turns on a 10 dB preamp, the scale must change to -130 to -30 dBm, >> because the preamp has made the receiver more sensitive while also reducing >> the max permissible level. >> >> Conversely, if the operator turned on 10 dB of attenuation, then the scale >> would shift upward to -110 to -10 dBm, indicating clearly that sensitivity >> is being sacrificed for greater large signal handling capability. The noise >> floor, being a relative constant, would move closer to the bottom of the >> window, or rather, the window would move relative to the noise floor in >> such a way as to place it 10 dB closer to the bottom end. >> >> So actually, as I'm thinking about this, the meter wouldn't move at all. >> It's the noise marker that would float higher and lower within the window >> as you varied the controls, just as on an S-meter. I guess what I'm >> describing here is more or less an S-meter calibrated in dBm! >> >> But perhaps the best reason for looking at the receiver this way would be >> to tune the controls precisely for a given noise floor. Twenty meters, with >> its -120 dBm noise floor, will require one combination of preamps and/or >> attenuators. On 80 meters, if the noise is, say, -100 dBm, the operator >> knows (because he can see the graphic) exactly how much attenuation is >> acceptable while still keeping the band noise marker in the operating >> range. It would behoove the operator to keep the noise floor marker near >> the bottom to 1) give him the maximum dynamic range under those conditions, >> and 2) to avoid becoming "my K4 is noisy" guy. >> >> Presumably, as each K4 goes through RF calibration at the factory it will >> know exactly the gain of each preamp, attenuator, filter, and splitter in >> its path. The scale could be custom for each individual unit, although I >> wouldn't want to start any "my K4 is more sensitive than yours" wars. >> >> I leave it to the programmers to decide on the specific eye candy of such >> a readout. I for one would find this type of meter fun and useful in >> getting a mental picture of where in dynamic range space the receiver is >> sitting. >> >> Can anybody see any flaws in this idea? I can foresee at least one. I >> don't know how the front end of the K4 will work, but if it is constantly >> moving the receiver range in response to what it hears, that is, in >> response to the total amount of power incident on its antenna port, then >> perhaps that might pose a real challenge to giving this type of feedback to >> the user. I don't know. >> >> Al W6LX >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [email protected] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
