[Elecraft] KX3 AM-breakthrough
My KX3 when driven by a allband shortwave antenna shows am-breakthough at all bands above 30M depending on conditions. The source are far shortwave broadcast stations (relative to Germany), Iran, Pakistan, India and sometimes Deutsche Welle. The stations hearable then are different each time and very loud, S4 to S5, and so disturbing that working in cw is impossible for me. The antenna I use is an asymmetrical dipole(30m/40m long), tuned at the feedpoint by an SGV-230 autotuner and works well at all bands from 160m to 6m. The KX3 is designed as a portable trx. Outdoors people will use the long antennas which they have no room for at home. It seems the KX3-RX can not withstand the rf-levels delivered by such long antennas. ARLL and Sherweng measurents do not capture the situation thus showing that measurements at best always do picture only a part of reality. Is Elecraft working at this problem and is there a solution at the horizon? -- 73, Klaus DF1TL __ 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] KX3 AM-breakthrough
Thank you all for taking the time to answer to this issue. I will respond to some of the arguments and tips .. Klaus, I already have current baluns at both ends of the coax cable. The KX3 is driven by an analog old PS30 power supply, not a switching power supply. I already mentioned the AM stations are far ones. The last "Ortssender" around, Stuttgart Mühlacker, has been put out of service. Emory, same here, only when the broadcast bands open, good conditions, the effect takes place. Your double size G5RV delivers similar strong rf-levels as my antenna then. It is not one AM-station, depending on ionospheric conditions it may be and often is every time another one. Uwe, "very annoying", that's the point. Ralf, I think, because the AM-breakthrough signals are hearable at every frequency they are not mixing products from a nearby electronic device or a diode build by corrosion. This would cause a lot of but discrete signals. Matt and Don, if this is a problem with _any_ zero frequency IF (direct conversion) receiver then the KX3's concept would be a design error. ( I hope it is not.) If I switch to RX SHIFT I will have a receiver with the most advertised KX3 feature, narrow spaced dynamic range, dropping to values of rigs of the last century, like IC-735 or Lowe HF-235 or Drake SW8. (see http://www.sherweng.com/table.html) Additional I would have thrown the money for the roofing filters out of the window, as we say here in Germany. I hope there is a possiblity of rejection by software, but I have no expertise in SDR at all. No one of Elecraft has answered up to now, so I stay curious. -- 73 Klaus DF1TL __ 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] KX3 AM-breakthrough
Again, thank you all for taking the time to contribute to the issue. Ken, there was a relay of Radio China in Albania but I don't know if it is actually active. Ralf, this morning I "measured" the vfo leakage with my second receiver a NRD-535 connected to a R&S active antenna positioned at about two meters distance from the feedpoint of my dipole. At 15m the received vfo signal was about S3, dropping down to just noticeable if I switched on the isolation amplifier. I wonder why this isolation amplifier is off by default, but assume the reason is to save battery power which does not matter in case of use as home station. So I would like to know if there are any degradations in IP3 or more probable in opposite sideband suppression if this amplifier is permanent in the signal path because of additional phase shifts. As far as I remember this case is not included in the OSB adjustment procedure. I was astonished to see during OSB adjustment how sensitve the procedure is to frequeny dependend phase shifts which I never thought they could be of importance. Every 10th mm on the circuit board and every ns in software seems to matter. Wayne, could you please drop a few words about this? I assume such small rf-levels are not able to cross-modulating the local oscillator's "carrier" in the AC mains. In general I agree with your technical analysis and hope we met us on the bands some day for a longer talk. "If the AM breakthrough is a real (direct rectification) one, the 90 degree phaseshift between the two quadrature "channels" would probably not occur (in contrast to "true" signals). This could probably be used for suppressing it by software (?)" I such a direction my hopes went. Wayne, thank you very much for answer, technical statements, clarification and your offer. Now the reason of this AM-breakthrough is determined by the relevant authority. Good to hear as well that the dynamic range at 2 kHz drops not as far as I assumed because of the data measured by Sherweng. To your offer, which is much appreciated, I have several technical questions but these we will handle in separate e-mails as desired. Igor, I agree the problem is not a permanent one, as I already wrote and in no way my intention was to cast a bad light on the KX3. I already had a lot of fun and fine dx qso's with it. But if your are in a cw-qso at 15m and suddenly because of this AM-breakthrough you can't complete it, that's annoying. "Did you send message to elecraft technical support? Or do you expect them to answer your concerns here on the reflector? They sure are not obliged to do the latter." Shure they are not, but in practice they do. :-) I contacted qrp-project (main Elecraft distributor in Germany) before. They told me the problem is already known but the reason unclear. Now, now it is clear. :-) "BTW, later you may discover couple of other issues with KX3 which are not that obvious and which I have already discovered. Or you may just search this reflector and find out." I will look at your contributions to find out or contact you direct. OK? I am always interested in problems. :-) -- 73 es mny tnx Klaus DF1TL __ 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] KX3 Firmware 1.61 High Current / Low Power at 12m
I updated my KX3 with Firmware 1.61. Criticism: At 12m the output power gets reduced to 5W after the message "high current", sometimes even without this message. This happens with ATU tuned to a SWR of 1/1.2 as well as without ATU at an SWR 1/1.4 then. All other bands did not show this problem even with higher SWRs. Praise: The SSB weaver demodulation together with FL2 works just great. Much better perceivability and S/N ratio. Great work! -- 73, Klaus DF1TL __ 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] K3 SUB-RX works , but not in diversity mode
SUB-RX works (gets signals) but not in diversity mode. I assembled K3 serial# 8887 (FW-5.14) so far succesful but have a problem with the SUB RX and diversity. I plugged the coax from the BNC AUX-RX into the KRX3 at assembly time. When I switch on the SUB RX it gets its antenna input from there, which I can verify by plugging out the antenna connected to BNC AUX-RX and do not hear anymore the signals received before. So the connection between the antenna connected to AUX-RX and the KRX3 is already established and working. ! When I now, while SUB is active, press and hold SUB, the diversity ! mode is established and the decimal point of VFO A starts blinking, ! I hear a relay switching noise out of the K3 and the signal received ! by the SUB-RX before went off. So it looks to me as if the KRX3 is disconnected from my receiving antenna by switching from SUB to SUB-diversity. What gets switched at this moment and why? Switching on diversity should only bind/link the SUB RX to VFO A (the same as pressing A->B after changing frequency) but phase coupled this time, or I am totally wrong? Switching between Config:KRX3 ATU and AUX makes on difference, and no relay clicking is audible. Can anyone with a newer K3 (and new syntesizers) tell me if he is oberserving the same behavior? I am not quite shure if I have overlooked something at assembly time or if this is a firmware bug. -- 73, Klaus, DF1TL __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 SUB-RX works , but not in diversity mode
Problem solved to my shame. I forgot to install the coax cable from J4 of the auxiliary KSYN3A to J2 of the main KSYN3A according to page 14 at the KSYN3A manual. Thanks to Wayne for pointing me to my failure. So not the antenna connection was lost but the SUBRX simply got no LO signal. Compunctious but nevertheless happy because I am now able to enjoy diversity receiving using my old R&S active antenna with the K3. -- 73, Klaus DF1TL __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KSYN3A newest firmware : VCO:MD menu entry still there and delivers error
K3 SN 8887 MCU 5.14 / DSP 2.83 / FPF 1.19, 2/26/2015 Latest Production Release I still see CONFIG: VCO:MD -- and calibration started (digits count uwards) after leaving the menu but ends with an error after some time. I assume this can be ignored, as the KSYN3A does not need calibration? Or is the KSYN3A not recognized by the firmware? -- 73, Klaus, DF1TL __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KSYN3A newest firmware : VCO:MD menu entry still there and delivers error
Am 03/22/15 um 16:40 schrieb Eric Swartz - WA6HHQ, Elecraft: The new KSYN3a does not need the synth cal step. As noted in the manual, that only applies to the older synthesizer. 73, Eric elecraft.com _..._ On Mar 22, 2015, at 7:39 AM, Klaus Dittrich wrote: K3 SN 8887 MCU 5.14 / DSP 2.83 / FPF 1.19, 2/26/2015 Latest Production Release I still see CONFIG: VCO:MD -- and calibration started (digits count uwards) after leaving the menu but ends with an error after some time. I assume this can be ignored, as the KSYN3A does not need calibration? Or is the KSYN3A not recognized by the firmware? -- 73, Klaus, DF1TL __ 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 Message delivered to elist_c...@elecraft.com Eric, thank you. I think I have read in the release notes that the item VCO:MD does not show up at all if the firmware has taken notice that a KSYN3a is installed. Maybe something more for the todo list .. :-) -- 73, Klaus, DF1TL __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] Wish to Elecraft: K3 CWT/Fine & SPOT/RIT
http://elecraft.mailman.qth.narkive.com/QwnNWqcg/k3-cwt-fine-spot-rit I discovered this question there and will join to it. Will the KX3 features: - CWT mode enables FINE tuning - SPOT with RIT enabled tunes RIT, not VFO A be ported to the K3? I liked these features at my KX3 a lot. And I think implementing these features at the K3 will be a great improvement as well. Scenario You are calling CQ and the answering station is not at your tx frequency. KX3: Tip spot and your rx-rit moves to the calling station. (your tx frequency will not change) K3: --- Tip spot and VFO-A (and so your TX frequency) moves to the calling station. May be the calling station wonders why you are vanished. As spot is good but sometimes can not be perfect, in my opinion it will be a good idea to auto switch on FINE tuning then. I wonder that after a such a long time the K3 exists noone else but John (KN5L) and now I missed these features. So Elecraft, can you set this at the TODO-List please. -- 73, Klaus, df1tl __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KXV3B preamp or preamps? K3BPF mods questions.
Does the KXV3B include a second preamplifier for the subreceiver or just one preamp for the main receiver? Is the antenna routing the same as before? If existent, can one use the preamplifier for the subreceiver together with the aux input of the subreceiver? Is the antenna routing the same as before or are there any differences now? When does Elecraft publish the modifications for the K3BPF to extend the frequency range down to 100 kHz? Where are these noise generating 9V regulators located? High res photos for the changes avaliable? Is adding simple capacitor across the 9V line really enough to bring the noise down? (There are low noise regulators available these days.) Maybe one of the testers of the promised modifications can come out with some information!? -- 73, Klaus, DF1TL __ 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 Message delivered to arch...@mail-archive.com
