Re: [Elecraft] [K3] K3 S-Meter and Noise
Tom, I have three radio's in my shack besides the K3. I've checked their S-meters with the recommended XG1 and all have comparable readings. All four are equally quiet without an antenna connected and with a dummy load connected. When connected to an antenna the K3 has about 2 S units more noise indicated than the other radios connected to the same antenna (A/B switch) and the noise level sounds about that much louder. All volume controls are at about 9 o'clock. This applies to most bands. Strangely, WARC bands seem to be mostly excepted. This afternoon I took the my K3, K2 and FT-857D mobile using a 54" Li'l Tarheel II screwdriver antenna tuned to 20 meters. I operated the K3 & K2 from a SLA battery with the van turned off. I was in a park with nothing electrical for at least a half mile. Volume was again set at 9 0'clock on all three. The K3 have a steady S1 with peaks to S3. The other radios had S0 with no peaks. Volumes sounded appropriate for indicated S-meter reading. I've almost completely disassembled the radio and reassembled it and done the EE INIT reset with no change. It's apparent this K3 is more sensitive to antenna noise than the other four radio's which are all about equal. This leads me to believe this particular radio is going to bury weak signals in noise making them harder to dig out than the other radios. I've exchanged several emails with support and next week I'm supposed to talk with someone higher up at Aptos. I'm trying to be patient with this but it has been over a month since I placed the initial order. During assembly I had to replace the DSP board for an unrelated problem. If the radio has to go back to Aptos it will be close to two months since ordering before I have a fully functional radio. Have a good day and 73, Jim, W0EM Radio Amateur N5GE wrote: > > On Thu, 24 Sep 2009 15:18:33 +, Jim Harris wrote: > >> >>Hi All, >> >>I've had my new K3 up and running for about a week after replacing the DSP board during assembly due to the 5vdc rail being shorted to ground. The S-meter shows about S-2/3 noise and there is about an equal level of noise from the speaker. I have an IC-756ProIII sitting beside it and it shows S-0 with minimum noise from the speaker. Of course, I'm using the same mode and have set the filters in both to the same width. I have played with the preamp and attenuator in both and the K3 always shows a higher noise level with accompanying S-meter reading. >> >>My K2 is extremely quiet and does just great on the many portable trips I take. I may well be missing something on the K3 in all the myriad menu settings of the K3 but don't have a clue at this point as to how to proceed. I sure don't want to think this $2000 radio has such a noise problem and I'm going to have to live it. Does anyone have any information that may help? I would be most appreciative. >> >>Thank you, have a good day and 73. >> >>Jim, W0EM >> > [snip] > > Have you compared the two rigs with their antennas disconnected? Are > they both on the same antenna? Have you calibrated the Icon/K2 > S-Meters with a known 50 microvolt signal? What band are you on? > > Just a guess, but it sounds like the K3 has a more sensitive RX than > the other two. > > 73, > > Tom, N5GE > > n...@n5ge.com > K3 #806, K3 #1055, PR6, > XV144, XV432, KRC2, > W1 and other small kits. > > 2 W2's on order > 1 K144XV on order > > http://www.n5ge.com > http://www.swotrc.net > > > __ > 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 > > -- View this message in context: http://n2.nabble.com/K3-S-Meter-and-Noise-tp3706850p3762588.html Sent from the [K3] 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] K3 S-Meter and Noise
Jim, I know perception is 99% of reality, but your measurement technique is not entirely valid. The proper way to make the determination of sensitivity is to measure the MDS of each of the receivers. Use your XG1 signal generator to determine the MDS of each reciever using the technique outlined in the XG1 manual. A more sensitive receiver will create more "antenna noise" than one that is less sensitive. Say that the K3 can hear a -138 dBm signal, and the atmospheric noise is -136 dBm, then the K3 will hear all signals on that band that are greater than that -136 dBm noise level. If the MDS of the other receivers is at -132 dBm, they will not be able to hear the atmospheric noise, and will also not be able to hear a signal of -133 dBm either. A receiver that hears more 'antenna noise' is usually the more sensitive one. The noise floor - the noise level with the antenna disconnected - is the limit where the receiver will mask weak signals. OTOH, atmospheric noise (antenna noise) will mask signals on all receivers. 73, Don W3FPR Jim HaRRIS wrote: > Tom, > > I have three radio's in my shack besides the K3. I've checked their > S-meters with the recommended XG1 and all have comparable readings. All > four are equally quiet without an antenna connected and with a dummy load > connected. When connected to an antenna the K3 has about 2 S units more > noise indicated than the other radios connected to the same antenna (A/B > switch) and the noise level sounds about that much louder. All volume > controls are at about 9 o'clock. This applies to most bands. Strangely, > WARC bands seem to be mostly excepted. > > This afternoon I took the my K3, K2 and FT-857D mobile using a 54" Li'l > Tarheel II screwdriver antenna tuned to 20 meters. I operated the K3 & K2 > from a SLA battery with the van turned off. I was in a park with nothing > electrical for at least a half mile. Volume was again set at 9 0'clock on > all three. The K3 have a steady S1 with peaks to S3. The other radios had > S0 with no peaks. Volumes sounded appropriate for indicated S-meter > reading. > > I've almost completely disassembled the radio and reassembled it and done > the EE INIT reset with no change. > > It's apparent this K3 is more sensitive to antenna noise than the other four > radio's which are all about equal. This leads me to believe this particular > radio is going to bury weak signals in noise making them harder to dig out > than the other radios. > > I've exchanged several emails with support and next week I'm supposed to > talk with someone higher up at Aptos. I'm trying to be patient with this > but it has been over a month since I placed the initial order. During > assembly I had to replace the DSP board for an unrelated problem. If the > radio has to go back to Aptos it will be close to two months since ordering > before I have a fully functional radio. > > Have a good day and 73, > > Jim, W0EM > > __ 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] K3 S-Meter and Noise
On Sat, 3 Oct 2009 19:33:59 -0700 (PDT), Jim HaRRIS wrote: Below > >Tom, > >I have three radio's in my shack besides the K3. I've checked their >S-meters with the recommended XG1 and all have comparable readings. All >four are equally quiet without an antenna connected and with a dummy load >connected. When connected to an antenna the K3 has about 2 S units more >noise indicated than the other radios connected to the same antenna (A/B >switch) and the noise level sounds about that much louder. All volume >controls are at about 9 o'clock. This applies to most bands. Strangely, >WARC bands seem to be mostly excepted. > >This afternoon I took the my K3, K2 and FT-857D mobile using a 54" Li'l >Tarheel II screwdriver antenna tuned to 20 meters. I operated the K3 & K2 >from a SLA battery with the van turned off. I was in a park with nothing >electrical for at least a half mile. Volume was again set at 9 0'clock on >all three. The K3 have a steady S1 with peaks to S3. The other radios had >S0 with no peaks. Volumes sounded appropriate for indicated S-meter >reading. > >I've almost completely disassembled the radio and reassembled it and done >the EE INIT reset with no change. > >It's apparent this K3 is more sensitive to antenna noise than the other four >radio's which are all about equal. This leads me to believe this particular >radio is going to bury weak signals in noise making them harder to dig out >than the other radios. > >I've exchanged several emails with support and next week I'm supposed to >talk with someone higher up at Aptos. I'm trying to be patient with this >but it has been over a month since I placed the initial order. During >assembly I had to replace the DSP board for an unrelated problem. If the >radio has to go back to Aptos it will be close to two months since ordering >before I have a fully functional radio. > >Have a good day and 73, > >Jim, W0EM [snip] As I said before, it sounds to me like your K3 has a better RX than your other two radios. 73, Enjoy your K3. Tom, N5GE n...@n5ge.com K3 #806, K3 #1055, PR6, XV144, XV432, KRC2, W1 and other small kits. 2 W2's on order 1 K144XV on order http://www.n5ge.com http://www.swotrc.net __ 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] K3 S-Meter and Noise
Jim HaRRIS wrote: > > > All four are equally quiet without an antenna connected and with a dummy > load connected. When connected to an antenna the K3 has about 2 S units > more noise indicated than the other radios connected to the same antenna > (A/B switch) and the noise level sounds about that much louder. > Do not trust S-meter readings in making comparisons. See my response on Sept 26: http://www.mail-archive.com/elecraft@mailman.qth.net/msg82855.html 73, Bill -- View this message in context: http://n2.nabble.com/K3-S-Meter-and-Noise-tp3706850p3763762.html Sent from the [K3] 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] K3 S-Meter and Noise
Radio Amateur N5GE wrote: > > As I said before, it sounds to me like your K3 has a better RX than > your other two radios. > Or at least the S meter is more sensitive. According to the manual, the K3 S meter should display S3 with 1uV of input. With most radios, the S meter runs off the AGC so you will not see any S meter movement until the signal is strong enough to start activating AGC, which is probably at least 1uV. - Julian, G4ILO. K2 #392 K3 #222. * G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html -- View this message in context: http://n2.nabble.com/K3-S-Meter-and-Noise-tp3706850p3764185.html Sent from the [K3] 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
