K3S QST Article
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Wes,
This would be a simple firmware change, and it might be worth considering. But typically we see -30 dBc or better at 12 W in production with the latest revisions. 73, Wayne N6KR On Oct 15, 2016, at 7:59 AM, Wes Stewart <[hidden email]> wrote: > ….I would recommend that Elecraft change firmware to set the max power out at 10W (LP) and switch in the KPA100 above 10W, not 12. ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by kstover
No doubt in 1991 they were using bipolar transistors, which in some cases could hit a "magic" combination that resulted in better than average performance. These days everyone uses MOSFETs, which are consistently in the -30 dBc range on at least one band. The K3S with the latest updates averages about -35 dBc at 100 W (see ARRL review).
Wayne N6KR On Oct 15, 2016, at 8:05 AM, Kevin <[hidden email]> wrote: > Yaesu's secret was the ARRL. Unless things have changed they test at one frequency and assume the other bands produce the same results. > > I'll reverse the question, what has Yaesu done to rigs since 1991 that they can't reproduce those numbers? > > > On 10/14/2016 10:03 PM, Dave Hachadorian wrote: >> Yaesu FT-990, 12V finals >> 3rd order TX IMD -38dB >> ARRL Review 11/91 >> >> ARRL heaped glowing praise upon this rig way back in 1991 for its >> Tx IMD performance. So, what was Yaesu's secret, and why haven't manufacturers figured it out and capitalized on it ever since? >> >> Dave Hachadorian, K6LL >> Yuma, Arizona >> >> >> -----Original Message----- From: Kevin >> Sent: Friday, October 14, 2016 5:14 PM >> To: [hidden email] >> Subject: Re: [Elecraft] K3S QST Article >> >> The cause for this is the use of 12V finals. It would be much >> improved >> by moving to 24 or 50V finals. >> >> Move the /K3s II/ to 50V finals, say a pair of MRF 150's, limited >> to 150 >> or 200W max output. Design/Sell an outboard 50V switching supply >> capable >> of 15-20A continuous current, with a 10A 12V switcher built in >> for the >> rest of the radio. >> >> >> On 10/14/2016 1:33 PM, Bill Leonard N0CU wrote: >>> I would not expect the synthesizer (old or new) to be a >>> contributor the IMD >>> issue. Hopefully someone will correct me if that is a bad >>> assumption. To me, >>> the primary issue appears to be the linearity of the two RF >>> power >>> amplifiers. >>> >>> >> > > -- > R. Kevin Stover > AC0H > ARRL > FISTS #11993 > SKCC #215 > NAQCC #3441 > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by kstover
It seems to me that this solution would tie the K3S++ to mains
power. Being tied to mains power would impact my club's use of K3s with batteries on events like the California QSO party. (Our location does not permit generators.) I don't know how much such a restriction would shrink the K3S market. A voltage booster could be a solution. Such a device would have to be well shielded and bypassed to avoid RFI. It could either be internal to the radio or a "bump on the power cable". Such devices are available in the market and seem to work well. 73 Bill AE6JV On 10/14/16 at 5:14 PM, [hidden email] (Kevin) wrote: >The cause for this is the use of 12V finals. It would be much improved by moving to 24 or 50V finals. > >Move the /K3s II/ to 50V finals, say a pair of MRF 150's, >limited to 150 or 200W max output. Design/Sell an outboard 50V >switching supply capable of 15-20A continuous current, with a >10A 12V switcher built in for the rest of the radio. ----------------------------------------------------------------------- Bill Frantz | Concurrency is hard. 12 out | Periwinkle (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave www.pwpconsult.com | - Jeff Frantz | Los Gatos, CA 95032 ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Wayne,
Ok, I'll defer to your numbers. Offhand I don't have mine handy, but I was pretty amazed at how quickly the IMD rose above 10W. I'm not saying anything new here, back in December in this thread http://elecraft.365791.n2.nabble.com/Powering-a-K3s-from-a-battery-tt7611959.html#a7611980, I said among other things: "All I'm saying is that if you run the LPA at 10-12 watts, according to my measurements*, the IMD is pretty bad. If you have an HPA, then after it's kicked in, (13W in my K3S) the LPA is running at greatly reduced power. I don't believe Elecraft has to change anything. Guys with a KPA3(A) just need to avoid the grey area of 10-15W. *Remarkably, IMD measurements I made on my K3S using modest equipment correlated within 1dB or less to measurements made by Elecraft, on the same radio. " Wes On 10/15/2016 8:07 AM, Wayne Burdick wrote: > Wes, > > This would be a simple firmware change, and it might be worth considering. But typically we see -30 dBc or better at 12 W in production with the latest revisions. > > 73, > Wayne > N6KR > > > On Oct 15, 2016, at 7:59 AM, Wes Stewart <[hidden email]> wrote: > >> ….I would recommend that Elecraft change firmware to set the max power out at 10W (LP) and switch in the KPA100 above 10W, not 12. > > > > ______________________________________________________________ > 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 > Message delivered to [hidden email] > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Bill Frantz
There was a major initiative at least 15 years ago in the automotive industry to go to 28 volt systems in order to reduce the cost and weight of the heavier wires that were needed to cope with the expanding current drain as more things in the car went electronic. Not sure what happened to that since I've been retired, but I assume ways were found to make the new electronics more energy efficient in the first place. As I remember, one of the issues holding back 28 volt systems was the higher breakdown voltages that would be needed for the various semiconductors involved ... not everything gets more efficient or cost effective as voltages go up. 73, Dave AB7E On 10/15/2016 12:49 PM, Ron D'Eau Claire wrote: > And therein lies the reason for using 12V. It would have been easier had we > gone from 6V automotive power to 28V as is used on many aircraft so > manufacturers were encouraged to build generators and equipment for that > voltage, but that didn't happen. > > 73, Ron AC7AC ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by kstover
Quote:
"Unless things have changed they test at one frequency and assume the other bands produce the same results. " Hi, I don't believe this is true. The ARRL publishes a "typical" IMD figure and a "worst case" figure which I assume to be the worst case for any band and they they publish which band this is (12m for the recent K3S review). Anyway, this doesn't change the fact that about 600 K3S purchasers are faced with the prospect of having to face the cost and inconvenience of having to return their rigs (I am one of them) to fix this apparent design flaw. Not to do so would be unethical (to transmit with excessive IMD). AB2TC - Knut
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In reply to this post by wayne burdick
Wayne,
For those of us with the unmodified KLPA3A (10 W module), can the mods be done by a skilled engr/tech. If so, can the parts be made available as a kit. If not, can just the module be sent in for modification instead of the whole radio. Bill N0CU |
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In reply to this post by David Gilbert
Hi,
Well, as I remember it there was once a push to move to 48V for automotives but that never happened (so far). I was always skeptical on the wisdom on moving to FET finals at the 12V level. Generally bipolars work better at this low voltage. FETs come come into their own at higher voltages (24-75V). In general I still think it is silly to make modern radios compatible with the old 12V car power system. For portable use there are plenty of ways to provide higher voltages. (Eventually power supplies manufacturers will make notice.) AB2TC - Knut
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The reason DC power systems in vehicles and aircraft used 28 V or less
historically is that that was the highest DC voltage that could be switched mechanically without excessive arcing. (Has to do with the energy required to pull electrons out of metals, I believe.) With the solid state switching devices now available, of course, higher voltages could now be used. OT, I know, but I always thought that was interesting. 73, Scott K9MA On 10/15/2016 19:46, ab2tc wrote: > Hi, > > Well, as I remember it there was once a push to move to 48V for automotives > but that never happened (so far). > > I was always skeptical on the wisdom on moving to FET finals at the 12V > level. Generally bipolars work better at this low voltage. FETs come come > into their own at higher voltages (24-75V). > > In general I still think it is silly to make modern radios compatible with > the old 12V car power system. For portable use there are plenty of ways to > provide higher voltages. (Eventually power supplies manufacturers will make > notice.) > > AB2TC - Knut > > > David Gilbert wrote >> There was a major initiative at least 15 years ago in the automotive >> industry to go to 28 volt systems in order to reduce the cost and weight >> of the heavier wires that were needed to cope with the expanding current >> drain as more things in the car went electronic. Not sure what happened >> to that since I've been retired, but I assume ways were found to make >> the new electronics more energy efficient in the first place. As I >> remember, one of the issues holding back 28 volt systems was the higher >> breakdown voltages that would be needed for the various semiconductors >> involved ... not everything gets more efficient or cost effective as >> voltages go up. >> >> 73, >> Dave AB7E >> >> >> On 10/15/2016 12:49 PM, Ron D'Eau Claire wrote: >>> And therein lies the reason for using 12V. It would have been easier had >>> we >>> gone from 6V automotive power to 28V as is used on many aircraft so >>> manufacturers were encouraged to build generators and equipment for that >>> voltage, but that didn't happen. >>> >>> 73, Ron AC7AC >> ______________________________________________________________ >> -- Scott K9MA [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Bill Frantz
Bill,
Another good solution is LiFePO4 batteries, which have a relatively flatter discharge curve than Lead-Acid, and that discharge curve is much closer to 13V for LiFePO4 than 11.5V for Lead Acid. Yes, they're more expensive to buy, but they last a lot longer. 73, Jim K9YC On Sat,10/15/2016 8:32 AM, Bill Frantz wrote: > It seems to me that this solution would tie the K3S++ to mains power. > Being tied to mains power would impact my club's use of K3s with > batteries on events like the California QSO party. (Our location does > not permit generators.) I don't know how much such a restriction would > shrink the K3S market. ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by ab2tc
Knut,
The K3S as originally shipped does not have a design flaw. Like virtually all 12-V-class transceivers using currently available MOSFETs, it was already right around -30 dBc or better, worst-case, for 3rd-order IMD. We simply found a way to make it better by a few dB, and we're offering to make this upgrade at no charge. 73, Wayne N6KR ______________________________________________________________ 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 Message delivered to [hidden email] |
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Wayne, if IMD can be improved by reducing first amp power, 12-13 watt out to 10watt out, by a firmware modification, can you make this choice?
I wouldnt like to make works on my new K3S... Ian IK4EWX Invio eseguito dallo smartphone BlackBerry 10. Messaggio originale Da: Wayne Burdick Inviato: lunedì 17 ottobre 2016 02:26 A: ab2tc Cc: [hidden email] Oggetto: Re: [Elecraft] K3S QST Article Knut, The K3S as originally shipped does not have a design flaw. Like virtually all 12-V-class transceivers using currently available MOSFETs, it was already right around -30 dBc or better, worst-case, for 3rd-order IMD. We simply found a way to make it better by a few dB, and we're offering to make this upgrade at no charge. 73, Wayne N6KR ______________________________________________________________ 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 Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Has the mechanism for the K3S returns been set up yet?
I suppose turn-around time also needs clarification too. Not many manufacturers would do this sort of upgrade, let alone for 'free'. Thanks! 73, Jim Jim Finan AB4AC Sent from my BlackBerry 10 smartphone. Original Message From: Wayne Burdick Sent: Sunday, October 16, 2016 8:26 PM To: ab2tc Cc: [hidden email] Subject: Re: [Elecraft] K3S QST Article Knut, The K3S as originally shipped does not have a design flaw. Like virtually all 12-V-class transceivers using currently available MOSFETs, it was already right around -30 dBc or better, worst-case, for 3rd-order IMD. We simply found a way to make it better by a few dB, and we're offering to make this upgrade at no charge. 73, Wayne N6KR ______________________________________________________________ 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 Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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Jim,
Contact support to get all the latest information on the upgrade and start the process for sending it in. 73, Don W3FPR On 10/17/2016 8:50 AM, Jim Finan wrote: > Has the mechanism for the K3S returns been set up yet? > > I suppose turn-around time also needs clarification too. ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Wayne,
Is there a way to do this " at home" ? Since I´m in Sweden it might not be practical to send the radio all the way to California for this. 73 Jim SM2EKM ---------------------------------------------- On 2016-10-17 02:25, Wayne Burdick wrote: > Knut, > > The K3S as originally shipped does not have a design flaw. Like virtually all 12-V-class transceivers using currently available MOSFETs, it was already right around -30 dBc or better, worst-case, for 3rd-order IMD. We simply found a way to make it better by a few dB, and we're offering to make this upgrade at no charge. > > 73, > Wayne > N6KR > ______________________________________________________________ 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 Message delivered to [hidden email] |
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Is this there a SN after which these upgrades are automatically included in
all K3S's? On Mon, Oct 17, 2016 at 10:56 PM, Jan Erik Holm <[hidden email]> wrote: > Wayne, > > Is there a way to do this " at home" ? Since I´m in Sweden > it might not be practical to send the radio all the way to > California for this. > > 73 Jim SM2EKM > ---------------------------------------------- > On 2016-10-17 02:25, Wayne Burdick wrote: > >> Knut, >> >> The K3S as originally shipped does not have a design flaw. Like virtually >> all 12-V-class transceivers using currently available MOSFETs, it was >> already right around -30 dBc or better, worst-case, for 3rd-order IMD. We >> simply found a way to make it better by a few dB, and we're offering to >> make this upgrade at no charge. >> >> 73, >> Wayne >> N6KR >> >> > ______________________________________________________________ > 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 > Message delivered to [hidden email] > 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 Message delivered to [hidden email] |
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If the serial number is 10939 or greater, the change has already been
installed. At slightly lower serial numbers (10852 and above) it may or may not have been installed - it depends on whether it is a kit or factory assembly and whether it is a K3S/10 or K3S/100. If you are in the 'questionable' serial number range, contact Elecraft support for detailed information. If below S/N 10852, the change has not been installed. 73, Don W3FPR On 10/18/2016 10:29 AM, Bob Steding wrote: > Is this there a SN after which these upgrades are automatically included in > all K3S's? > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Edward A. Dauer
I like the size and weight of K3 also. K3 fits right underneath the seat in front of you as a carry on, and K3 is as good or better than an Orion or FT-5000 that will not fit in there, hi! What other contest radio can do this?
Elecraft K2/100. Yes, you can build it with the separate receive antenna and with computer control of the radio. Of course K3 has other advantages, like diversity receive which is routine at n2cei 160m station in FL. Plus there is a second K3 for S & P of mults. This requires the K3 lock-out feature so that only one K3 is transmitting. And there is remote control. This year in CQ 160m contest I couldn't make the trip to FL so the n2cei group sent to me the other half of the remote gear and I operated my leg of n2cei M/M 160m anyway, from Idaho. Cool. 73, Will, wj9b, ID occasional multi- op at big-gun ny4a NC and 160m superstation n2cei FL CWops #1085 CWA Advisor levels II and III http://cwops.org/ -------------------------------------------- On Tue, 10/18/16, Bill Frantz <[hidden email]> wrote: Subject: Re: [Elecraft] K3S QST Article To: [hidden email] Date: Tuesday, October 18, 2016, 7:04 AM Since June, my K3 went out for the California QSO Party (CQP), a special event station from Ely NV, and field day. Field day and CQP were solar powered battery. The Ely event ended up being battery because the generator was putting out S9 noise. The field day was QRP while CQP and Ely were at 100W. Being able to drop back to battery saved our bacon in Ely. For all these events, and in the shack, I am very glad to have a radio with the ease of use of the K3, which IMHO, is better than my KX3. On 10/17/16 at 4:47 PM, [hidden email] (Kevin) wrote: >How many people take their K3(s) out in the >sticks...ever...save Field Day? ----------------------------------------------------------------------- Bill Frantz | Can't fix stupid, but duct | Periwinkle (408)356-8506 | tape can muffle the sound... | 16345 Englewood Ave www.pwpconsult.com | - Bill Liebman | Los Gatos, CA 95032 ______________________________________________________________ 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 Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Don Wilhelm
We sent an earlier posting showing which serial numbers already had the new upgrades:
KPA3A upgrade incorporated starting with serial number: Factory assembled: s/n 10852 Kit: s/n 10864 LPA module upgrade incorporated starting with serial number: Factory assembled: s/n 10920 Kit: s/n 10939 73, Wayne N6KR On Oct 18, 2016, at 7:52 AM, Don Wilhelm <[hidden email]> wrote: > If the serial number is 10939 or greater, the change has already been installed. > At slightly lower serial numbers (10852 and above) it may or may not have been installed - it depends on whether it is a kit or factory assembly and whether it is a K3S/10 or K3S/100. > If you are in the 'questionable' serial number range, contact Elecraft support for detailed information. > If below S/N 10852, the change has not been installed. > > 73, > Don W3FPR > > On 10/18/2016 10:29 AM, Bob Steding wrote: >> Is this there a SN after which these upgrades are automatically included in >> all K3S's? >> > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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