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> On Sep 14, 2020, at 11:03 AM, [email protected] wrote: > > Send Elecraft mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.qth.net/mailman/listinfo/elecraft > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Elecraft digest..." > > > Today's Topics: > > 1. Why predistortion ? (JR) > 2. Re: Why predistortion ? (Wayne Burdick) > 3. Re: Why predistortion ? (E.H. Russell) > 4. Re: Why predistortion ? (Randy Farmer) > 5. KAT500: Fails to tune, and shows 3:1 on good antenna on 18 > MHz. (Dave Cole) > 6. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Dick Dievendorff) > 7. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Ken Winterling) > 8. Why predistortion ? (John Harper) > 9. Re: Why predistortion ? (Wes) > 10. Re: Why predistortion ? (W2xj) > 11. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Dave Cole) > 12. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Dave Cole) > 13. Re: Why predistortion ? (David Gilbert) > 14. Re: Why predistortion ? (Bill Frantz) > 15. Re: Why predistortion ? (Wayne Burdick) > 16. Re: Why predistortion ? (Jim Brown) > 17. Re: Why predistortion ? (Jim Brown) > 18. Re: Why predistortion ? (David Gilbert) > 19. Elecraft CW Net Report (kevinr) > 20. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Dave Cole) > 21. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on > 18 MHz. (Ken Winterling) > 22. 630 meter operation on the K4 (Nigel Lemaire) > 23. Re: Why predistortion ? (Charlie T) > 24. Re: Why predistortion ? (Charlie T) > 25. Re: Why predistortion ? (Dr. William J. Schmidt) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 13 Sep 2020 17:32:21 -0400 > From: JR <[email protected]> > To: [email protected] > Subject: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Why are so many ops obsessed with predistortion? > > The Elecraft K-Line already produces some of the cleanest, purest > transmit signals around.?? Do we need predistortion ?? If so, why, and > how much better is it than what we already have?? Should I wait to buy a > new rig until that is available? > > Thanks and Happy Trails to all.?? K8JHR > _________________________________ > > > ------------------------------ > > Message: 2 > Date: Sun, 13 Sep 2020 15:03:00 -0700 > From: Wayne Burdick <[email protected]> > To: JR <[email protected]> > Cc: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8 > > Hi JR, > > Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD > in the range of -30 dBc (ARRL method) on some HF bands. This reflects a > limitation in the state of the art. Even with adequate feedback and bias, an > amplifier operated in the vicinity of its 1 dB compression point (where it is > most efficient) will exhibit such characteristics. > > To improve on this you either need to operate class A, which is highly > inefficient, or use predistortion. > > A small number of commercial transceivers are now providing predistortion, in > some cases as an optional/experimental setting (that not everyone uses, or at > least not all the time). There are constraints on predistortion power range > imposed by the headroom limit of the amplifier stage itself. Go over that > point and distortion will be worse than without predistortion. > > Predistortion, correctly applied, can reduce interference between adjacent > stations on a crowded band. This is a factor at least some fraction of the > time during typical amateur radio use. Beyond that, the motivation for a > ?pure? signal exemplifies the amateur spirit of cooperation, and is an > example of keeping the hobby on the forefront of electrical design. > > Wayne, > N6KR > > ---- > elecraft.com > >> On Sep 13, 2020, at 2:34 PM, JR <[email protected]> wrote: >> >> ?Why are so many ops obsessed with predistortion? >> >> The Elecraft K-Line already produces some of the cleanest, purest transmit >> signals around. Do we need predistortion ? If so, why, and how much >> better is it than what we already have? Should I wait to buy a new rig >> until that is available? >> >> Thanks and Happy Trails to all. K8JHR >> _________________________________ >> ______________________________________________________________ >> 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] > > > ------------------------------ > > Message: 3 > Date: Sun, 13 Sep 2020 18:41:52 -0400 > From: "E.H. Russell" <[email protected]> > To: "'Wayne Burdick'" <[email protected]>, "'JR'" > <[email protected]> > Cc: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > Well put. > > TKS, > 73 ED W2RF > > > > > -----Original Message----- > From: [email protected] <[email protected]> On > Behalf Of Wayne Burdick > Sent: Sunday, September 13, 2020 6:03 PM > To: JR <[email protected]> > Cc: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > > Hi JR, > > Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD > in the range of -30 dBc (ARRL method) on some HF bands. This reflects a > limitation in the state of the art. Even with adequate feedback and bias, an > amplifier operated in the vicinity of its 1 dB compression point (where it is > most efficient) will exhibit such characteristics. > > To improve on this you either need to operate class A, which is highly > inefficient, or use predistortion. > > A small number of commercial transceivers are now providing predistortion, in > some cases as an optional/experimental setting (that not everyone uses, or at > least not all the time). There are constraints on predistortion power range > imposed by the headroom limit of the amplifier stage itself. Go over that > point and distortion will be worse than without predistortion. > > Predistortion, correctly applied, can reduce interference between adjacent > stations on a crowded band. This is a factor at least some fraction of the > time during typical amateur radio use. Beyond that, the motivation for a > ?pure? signal exemplifies the amateur spirit of cooperation, and is an > example of keeping the hobby on the forefront of electrical design. > > Wayne, > N6KR > > ---- > elecraft.com > >> On Sep 13, 2020, at 2:34 PM, JR <[email protected]> wrote: >> >> ?Why are so many ops obsessed with predistortion? >> >> The Elecraft K-Line already produces some of the cleanest, purest transmit >> signals around. Do we need predistortion ? If so, why, and how much >> better is it than what we already have? Should I wait to buy a new rig >> until that is available? >> >> Thanks and Happy Trails to all. K8JHR >> _________________________________ >> ______________________________________________________________ >> 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] > > > > ------------------------------ > > Message: 4 > Date: Sun, 13 Sep 2020 18:48:17 -0400 > From: Randy Farmer <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > I can testify to the effectiveness of predistortion techniques from my 5 > years or so as a CDMA Cellular Base Station engineer with Motorola. The > first generation of CDMA transmitters had a very specific "spectral > mask" that had to be certified. As I recall, the transmitter output that > met the Spectral Mask requirements of something like -60 dBc outside of > the channel bandwidth showed up with essentially vertical sides (and a > very flat top) on a spectrum analyzer. Obtaining this performance was > neither cheap nor easy, and the associated testing was pretty stringent > as well. Meeting the specs demanded very sophisticated predistortion > techniques. Be glad that conventional SSB and the fairly simple > waveforms used in amateur digital comms don't require too much dynamic > headroom. The first generation CDMA waveform had a roughly 10:1, or 20dB > peak-to-average power ratio. This meant that the transmitters we > designed to produce 20W average power were actually capable of 200W > continuous output power and still met the spectral mask IMD > requirements. Putting multiple carriers through the PA required either > higher power capability or derating the power output for each individual > carrier. I no longer work in the industry, so I don't know what the > current generation of signals requires, but with the greater bandwidths > and more complex modulation schemes used now you can bet the > requirements, and therefore the transmitter design challenge, didn't get > any easier. > > 73... > Randy, W8FN > >> On 9/13/2020 6:03 PM, Wayne Burdick wrote: >> Hi JR, >> >> Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD >> in the range of -30 dBc (ARRL method) on some HF bands. This reflects a >> limitation in the state of the art. Even with adequate feedback and bias, an >> amplifier operated in the vicinity of its 1 dB compression point (where it >> is most efficient) will exhibit such characteristics. >> >> To improve on this you either need to operate class A, which is highly >> inefficient, or use predistortion. >> >> A small number of commercial transceivers are now providing predistortion, >> in some cases as an optional/experimental setting (that not everyone uses, >> or at least not all the time). There are constraints on predistortion power >> range imposed by the headroom limit of the amplifier stage itself. Go over >> that point and distortion will be worse than without predistortion. >> >> Predistortion, correctly applied, can reduce interference between adjacent >> stations on a crowded band. This is a factor at least some fraction of the >> time during typical amateur radio use. Beyond that, the motivation for a >> ?pure? signal exemplifies the amateur spirit of cooperation, and is an >> example of keeping the hobby on the forefront of electrical design. >> >> Wayne, >> N6KR >> >> ---- >> elecraft.com > > > ------------------------------ > > Message: 5 > Date: Sun, 13 Sep 2020 15:48:40 -0700 > From: Dave Cole <[email protected]> > To: [email protected] > Subject: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Hello, > My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., only. > Antenna is a single feedline to a 6BTV, and an analyzer says all is good > at low power. At 100 watts, all seems good. > > All other bands seem OK at high power. > > Question: When in bypass, is the entire tuner bypassed? > Question: When turned off is the tuner bypassed? Which antenna is default? > -- > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist > ARRL Asst. Director, NW Division, Technical Resources > > > ------------------------------ > > Message: 6 > Date: Sun, 13 Sep 2020 15:57:03 -0700 > From: Dick Dievendorff <[email protected]> > To: Dave Cole <[email protected]> > Cc: [email protected] > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8 > > When unpowered the KAT500 is bypassed, ANT1. > > When the ATU is in mode BYP, yes, it?s bypassed. > > 73 de Dick, K6KR > >> On Sep 13, 2020, at 15:52, Dave Cole <[email protected]> wrote: >> >> ?Hello, >> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., only. Antenna >> is a single feedline to a 6BTV, and an analyzer says all is good at low >> power. At 100 watts, all seems good. >> >> All other bands seem OK at high power. >> >> Question: When in bypass, is the entire tuner bypassed? >> Question: When turned off is the tuner bypassed? Which antenna is default? >> -- >> 73, and thanks, >> Dave (NK7Z) >> https://www.nk7z.net >> ARRL Volunteer Examiner >> ARRL Technical Specialist >> ARRL Asst. Director, NW Division, Technical Resources >> ______________________________________________________________ >> 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] > > > ------------------------------ > > Message: 7 > Date: Sun, 13 Sep 2020 19:24:24 -0400 > From: Ken Winterling <[email protected]> > To: Dick Dievendorff <[email protected]> > Cc: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: > <calk4bwijpgsxohauhbb14vcy7aps-u7cfoixybkq_rvu1zf...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > When you have issues like this the best test is to use a known good dummy > load. That removes the antenna system from the equation. See what happens > on 18mHz when transmitting into the summy load. > > Ken > WA2LBI > > > > > >> On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff <[email protected]> wrote: >> >> When unpowered the KAT500 is bypassed, ANT1. >> >> When the ATU is in mode BYP, yes, it?s bypassed. >> >> 73 de Dick, K6KR >> >>>> On Sep 13, 2020, at 15:52, Dave Cole <[email protected]> wrote: >>> >>> ?Hello, >>> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., only. >> Antenna is a single feedline to a 6BTV, and an analyzer says all is good at >> low power. At 100 watts, all seems good. >>> >>> All other bands seem OK at high power. >>> >>> Question: When in bypass, is the entire tuner bypassed? >>> Question: When turned off is the tuner bypassed? Which antenna is >> default? >>> -- >>> 73, and thanks, >>> Dave (NK7Z) >>> https://www.nk7z.net >>> ARRL Volunteer Examiner >>> ARRL Technical Specialist >>> ARRL Asst. Director, NW Division, Technical Resources >>> ______________________________________________________________ >>> 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] > > > ------------------------------ > > Message: 8 > Date: Sun, 13 Sep 2020 18:40:01 -0500 > From: John Harper <[email protected]> > To: Elecraft list <[email protected]> > Subject: [Elecraft] Why predistortion ? > Message-ID: > <CAPHmH=O3V_u977xn0c9qJ1hCEyxwfdVYMXXhL30QRg=fgmv...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Here's a demonstration of predistortion in use (relevant part starts at the > 10-minute point): > https://www.youtube.com/watch?v=0adHZOTqTlQ > > John AE5X > https://ae5x.blogspot.com > > >> Why are so many ops obsessed with predistortion? > > > ------------------------------ > > Message: 9 > Date: Sun, 13 Sep 2020 17:20:39 -0700 > From: Wes <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > You're kidding, right? > > Wes? N7WS > > >> On 9/13/2020 2:32 PM, JR wrote: >> The Elecraft K-Line already produces some of the cleanest, purest transmit >> signals around.... >> >> Thanks and Happy Trails to all.?? K8JHR > > > > ------------------------------ > > Message: 10 > Date: Sun, 13 Sep 2020 20:24:07 -0400 > From: W2xj <[email protected]> > To: Wayne Burdick <[email protected]> > Cc: [email protected], JR <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8 > > wayne, > > After you have the K4 fully put to bed, for your next project you might want > to consider an amp that is directly driven by an I/Q stream. The amplifier > will be much more efficient (less power consumption) and you start out with > less IMD before any pre-distortion. > > Sent from my iPad > >> On Sep 13, 2020, at 6:05 PM, Wayne Burdick <[email protected]> wrote: >> >> ?Hi JR, >> >> Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD >> in the range of -30 dBc (ARRL method) on some HF bands. This reflects a >> limitation in the state of the art. Even with adequate feedback and bias, an >> amplifier operated in the vicinity of its 1 dB compression point (where it >> is most efficient) will exhibit such characteristics. >> >> To improve on this you either need to operate class A, which is highly >> inefficient, or use predistortion. >> >> A small number of commercial transceivers are now providing predistortion, >> in some cases as an optional/experimental setting (that not everyone uses, >> or at least not all the time). There are constraints on predistortion power >> range imposed by the headroom limit of the amplifier stage itself. Go over >> that point and distortion will be worse than without predistortion. >> >> Predistortion, correctly applied, can reduce interference between adjacent >> stations on a crowded band. This is a factor at least some fraction of the >> time during typical amateur radio use. Beyond that, the motivation for a >> ?pure? signal exemplifies the amateur spirit of cooperation, and is an >> example of keeping the hobby on the forefront of electrical design. >> >> Wayne, >> N6KR >> >> ---- >> elecraft.com >> >>>> On Sep 13, 2020, at 2:34 PM, JR <[email protected]> wrote: >>> >>> ?Why are so many ops obsessed with predistortion? >>> >>> The Elecraft K-Line already produces some of the cleanest, purest transmit >>> signals around. Do we need predistortion ? If so, why, and how much >>> better is it than what we already have? Should I wait to buy a new rig >>> until that is available? >>> >>> Thanks and Happy Trails to all. K8JHR >>> _________________________________ >>> ______________________________________________________________ >>> 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] > > > > ------------------------------ > > Message: 11 > Date: Sun, 13 Sep 2020 17:53:36 -0700 > From: Dave Cole <[email protected]> > To: Dick Dievendorff <[email protected]> > Cc: [email protected] > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > That helps triage the issue... Something in my antenna must have gone > wonky... I am using a 6BTV, with the 18 Meter add on kit, so the same > feedpoint is used for all bands, and they are fine... I was worried it > was the tuner. I'll go check the antenna out tonight, and in the > morning as well... THANK YOU! Knowing the tuner is bypassed in Bypass, > helps... Next is to put a dummy load on the tuner... > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist > ARRL Asst. Director, NW Division, Technical Resources > >> On 9/13/20 3:57 PM, Dick Dievendorff wrote: >> When unpowered the KAT500 is bypassed, ANT1. >> >> When the ATU is in mode BYP, yes, it?s bypassed. >> >> 73 de Dick, K6KR >> >>>> On Sep 13, 2020, at 15:52, Dave Cole <[email protected]> wrote: >>> >>> ?Hello, >>> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., only. Antenna >>> is a single feedline to a 6BTV, and an analyzer says all is good at low >>> power. At 100 watts, all seems good. >>> >>> All other bands seem OK at high power. >>> >>> Question: When in bypass, is the entire tuner bypassed? >>> Question: When turned off is the tuner bypassed? Which antenna is default? >>> -- >>> 73, and thanks, >>> Dave (NK7Z) >>> https://www.nk7z.net >>> ARRL Volunteer Examiner >>> ARRL Technical Specialist >>> ARRL Asst. Director, NW Division, Technical Resources >>> ______________________________________________________________ >>> 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] > > > ------------------------------ > > Message: 12 > Date: Sun, 13 Sep 2020 17:54:02 -0700 > From: Dave Cole <[email protected]> > To: Ken Winterling <[email protected]>, Dick Dievendorff > <[email protected]> > Cc: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Thanks Ken... That is the next step... Now I need to locate one... > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist > ARRL Asst. Director, NW Division, Technical Resources > >> On 9/13/20 4:24 PM, Ken Winterling wrote: >> When you have issues like this the best test is to use a known good >> dummy load. That removes the antenna system from the equation. See what >> happens on 18mHz when transmitting into the summy load. >> >> Ken >> WA2LBI >> >> >> >> >> On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff <[email protected] >> <mailto:[email protected]>> wrote: >> >> When unpowered the KAT500 is bypassed, ANT1. >> >> When the ATU is in mode BYP, yes, it?s bypassed. >> >> 73 de Dick, K6KR >> >>> On Sep 13, 2020, at 15:52, Dave Cole <[email protected] >> <mailto:[email protected]>> wrote: >>> >>> ?Hello, >>> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., >> only. Antenna is a single feedline to a 6BTV, and an analyzer says >> all is good at low power.? At 100 watts, all seems good. >>> >>> All other bands seem OK at high power. >>> >>> Question:? When in bypass, is the entire tuner bypassed? >>> Question:? When turned off is the tuner bypassed?? Which antenna >> is default? >>> -- >>> 73, and thanks, >>> Dave (NK7Z) >>> https://www.nk7z.net >>> ARRL Volunteer Examiner >>> ARRL Technical Specialist >>> ARRL Asst. Director, NW Division, Technical Resources >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >> <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] <mailto:[email protected]> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] <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] <mailto:[email protected]> >> > > > ------------------------------ > > Message: 13 > Date: Sun, 13 Sep 2020 18:50:41 -0700 > From: David Gilbert <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > > I don't know where you got the idea that the K-Line produces the > cleanest signals.? As several people have pointed out, because of the 12 > volt finals the transmit IMD performance of the existing K-line is > relatively poor. > > Dave?? AB7E > > >> On 9/13/2020 2:32 PM, JR wrote: >> Why are so many ops obsessed with predistortion? >> >> The Elecraft K-Line already produces some of the cleanest, purest >> transmit signals around.?? Do we need predistortion ?? If so, why, and >> how much better is it than what we already have?? Should I wait to buy >> a new rig until that is available? >> >> Thanks and Happy Trails to all.?? K8JHR > > > > ------------------------------ > > Message: 14 > Date: Sun, 13 Sep 2020 21:59:13 -0400 > From: Bill Frantz <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: > <r480Ps-10146i-14E8D36EC339467BB106B11E38A936FF@Williams-MacBook-Pro.local> > > Content-Type: text/plain; charset=UTF-8; format=flowed > > Wayne is right, it's the right thing to do. And we amateurs try > to produce the best signals we can. (Ignore the wide CW signals > during contests. :-) ) > > But the value will also show up during multi-op situations like > running 14A during field day. Field day is much more fun if > everyone gets a chance to operate. > > 73 Bill AE6JV > > >> On 9/13/20 at 6:03 PM, [email protected] (Wayne Burdick) wrote: >> >> Predistortion, correctly applied, can reduce interference >> between adjacent stations on a crowded band. This is a factor >> at least some fraction of the time during typical amateur radio >> use. Beyond that, the motivation for a ?pure? signal >> exemplifies the amateur spirit of cooperation, and is an >> example of keeping the hobby on the forefront of electrical design. > > ----------------------------------------------------------------------- > Bill Frantz | Privacy is dead, get over | Periwinkle > (408)348-7900 | it. | 150 Rivermead > Rd #235 > www.pwpconsult.com | - Scott McNealy (1999) | Peterborough, > NH 03458 > > > > ------------------------------ > > Message: 15 > Date: Sun, 13 Sep 2020 19:14:52 -0700 > From: Wayne Burdick <[email protected]> > To: David Gilbert <[email protected]> > Cc: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=us-ascii > > 12 volts is a severe constraint for MOSFET PAs. But, like a lot of other > manufacturers, we accept this constraint so the equipment can be used in a > wide variety of portable/emergency power situations. As a result we have IMD > numbers in exactly the same range as other products that are subject to this > constraint. > > On the other hand, our transceivers are best in class in terms of transmitted > keying bandwidth. See paper by K9YC for example. Perhaps that's what JR was > thinking of. > > 73, > Wayne > N6KR > > > >> On Sep 13, 2020, at 6:50 PM, David Gilbert <[email protected]> wrote: >> >> >> I don't know where you got the idea that the K-Line produces the cleanest >> signals. As several people have pointed out, because of the 12 volt finals >> the transmit IMD performance of the existing K-line is relatively poor. >> >> Dave AB7E >> >> >>> On 9/13/2020 2:32 PM, JR wrote: >>> Why are so many ops obsessed with predistortion? >>> >>> The Elecraft K-Line already produces some of the cleanest, purest transmit >>> signals around. Do we need predistortion ? If so, why, and how much >>> better is it than what we already have? Should I wait to buy a new rig >>> until that is available? >>> >>> Thanks and Happy Trails to all. K8JHR >> >> ______________________________________________________________ >> 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] > > > > ------------------------------ > > Message: 16 > Date: Sun, 13 Sep 2020 21:14:47 -0700 > From: Jim Brown <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > >> On 9/13/2020 2:32 PM, JR wrote: >> The Elecraft K-Line already produces some of the cleanest, purest >> transmit signals around.?? Do we need predistortion ? > > If you care about a clean signal, YES! If you don't mind being a bad > neighbor, no. > > 73, Jim K9YC > > > ------------------------------ > > Message: 17 > Date: Sun, 13 Sep 2020 21:25:46 -0700 > From: Jim Brown <[email protected]> > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: > <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > >> On 9/13/2020 3:03 PM, Wayne Burdick wrote: >> Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD >> in the range of -30 dBc (ARRL method) on some HF bands. This reflects a >> limitation in the state of the art. > > I hope that this feature will be implemented for CW as well. CW is 100% > AM of a carrier by rectangular pulses, so any distortion in the transmit > chain results in clicks. Elecraft pioneered very clean keying waveforms; > it would be unfortunate for that to be lost with IMD in the power stages. > > 73, Jim K9YC > > > ------------------------------ > > Message: 18 > Date: Sun, 13 Sep 2020 21:43:21 -0700 > From: David Gilbert <[email protected]> > To: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > > > Of course, but that's a conscious choice by Elecraft and it does not > result in the "cleanest, purest signals around."? I give Elecraft tons > of credit for the other measures they have take to produce good signals, > which is why I own and will keep my upgraded K3 probably forever, but > K8JHR simply was incorrect in his comment and it makes a difference when > considering the expanding focus by folks like Sherwood and others to > clean up the bands.? When it comes to IMD, Elecraft is not one of the > better players.? The fact that that's by choice doesn't change > anything.? I suspect that 95+% of K3 rigs are used in portable/emergency > situations less than 5% of the time. > > 73, > Dave?? AB7E > > > >> On 9/13/2020 7:14 PM, Wayne Burdick wrote: >> 12 volts is a severe constraint for MOSFET PAs. But, like a lot of other >> manufacturers, we accept this constraint so the equipment can be used in a >> wide variety of portable/emergency power situations. As a result we have IMD >> numbers in exactly the same range as other products that are subject to this >> constraint. >> >> On the other hand, our transceivers are best in class in terms of >> transmitted keying bandwidth. See paper by K9YC for example. Perhaps that's >> what JR was thinking of. >> >> 73, >> Wayne >> N6KR >> >> >> >>>> On Sep 13, 2020, at 6:50 PM, David Gilbert <[email protected]> wrote: >>> >>> >>> I don't know where you got the idea that the K-Line produces the cleanest >>> signals. As several people have pointed out, because of the 12 volt finals >>> the transmit IMD performance of the existing K-line is relatively poor. >>> >>> Dave AB7E >>> >>> >>> On 9/13/2020 2:32 PM, JR wrote: >>>> Why are so many ops obsessed with predistortion? >>>> >>>> The Elecraft K-Line already produces some of the cleanest, purest transmit >>>> signals around. Do we need predistortion ? If so, why, and how much >>>> better is it than what we already have? Should I wait to buy a new rig >>>> until that is available? >>>> >>>> Thanks and Happy Trails to all. K8JHR >>> ______________________________________________________________ >>> 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] > > > > ------------------------------ > > Message: 19 > Date: Sun, 13 Sep 2020 21:51:33 -0700 > From: kevinr <[email protected]> > To: Elecraft Reflector <[email protected]> > Subject: [Elecraft] Elecraft CW Net Report > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Good Evening, > > ?? Signals were stronger than last week with less noise on both bands.? > QSB was a little higher on forty meters.? Most of you reported very nice > weather.? Even out west the weather is not too bad once you allow for > all the smoke.? It certainly makes working outside difficult.? Staying > inside helps but I still have a stuffy nose and a mild headache.? My > begonias don't like the smoke either, they are rapidly losing blossoms. > > ?? The forty meter net improves as the days grow shorter.? I was able > to reach Texas again.? Hopefully there will be some new sunspots this > week.? That would help my reach. > > > ? On 14050.8 kHz at 2200z: > > W0CZ - Ken - ND > > NO8V - John - MI > > AB9V - Mike - IN > > K6XK - Roy - IA > > > ? On 7047.5 kHz at 0045z: > > W0CZ - Ken - ND > > K0DTJ - Brian - CA > > K6PJV - Dale - CA > > W8OV - Dave - TX > > > I plan to work inside again this week.? I need to collect wood but > exercise in these smoky conditions makes the headaches worse. A week of > rain starting tomorrow night will help.? Maybe they will slow the fires > in the Cascades and clear our skies.? 2020 has been quite a year.? I'm > waiting for January so we can start over. > > ?? Until next week 73, > > ????? Kevin.? KD5ONS > > > - > > > > cutting angle = degrees(atan2(twist, PI() * caliber)) > > > > ------------------------------ > > Message: 20 > Date: Mon, 14 Sep 2020 04:52:03 -0700 > From: Dave Cole <[email protected]> > To: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Hi ken, > Added the dummy, no problems, so it is the antenna... Also, given it is > a 6BTV with the 18 meter add on, and all other bands work, it is not the > feedline... > > This makes it simple to fix! It is either a break with the laws of > physics as we understand them today-- or a connection has come loose. > Given there are only two connections... I suspect it will be a simple fix. > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist > ARRL Asst. Director, NW Division, Technical Resources > >> On 9/13/20 4:24 PM, Ken Winterling wrote: >> When you have issues like this the best test is to use a known good >> dummy load. That removes the antenna system from the equation. See what >> happens on 18mHz when transmitting into the summy load. >> >> Ken >> WA2LBI >> >> >> >> >> On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff <[email protected] >> <mailto:[email protected]>> wrote: >> >> When unpowered the KAT500 is bypassed, ANT1. >> >> When the ATU is in mode BYP, yes, it?s bypassed. >> >> 73 de Dick, K6KR >> >>> On Sep 13, 2020, at 15:52, Dave Cole <[email protected] >> <mailto:[email protected]>> wrote: >>> >>> ?Hello, >>> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., >> only. Antenna is a single feedline to a 6BTV, and an analyzer says >> all is good at low power.? At 100 watts, all seems good. >>> >>> All other bands seem OK at high power. >>> >>> Question:? When in bypass, is the entire tuner bypassed? >>> Question:? When turned off is the tuner bypassed?? Which antenna >> is default? >>> -- >>> 73, and thanks, >>> Dave (NK7Z) >>> https://www.nk7z.net >>> ARRL Volunteer Examiner >>> ARRL Technical Specialist >>> ARRL Asst. Director, NW Division, Technical Resources >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >> <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] <mailto:[email protected]> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] <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] <mailto:[email protected]> >> > > > ------------------------------ > > Message: 21 > Date: Mon, 14 Sep 2020 07:54:32 -0400 > From: Ken Winterling <[email protected]> > To: Dave Cole <[email protected]> > Cc: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good > antenna on 18 MHz. > Message-ID: > <calk4bwj_yephov1l5o3tgz3q4dwc_b4zt99mrd22g3-rk88...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > GL! > > Ken > WA2LBI > > > > > >> On Mon, Sep 14, 2020 at 7:53 AM Dave Cole <[email protected]> wrote: >> >> Hi ken, >> Added the dummy, no problems, so it is the antenna... Also, given it is >> a 6BTV with the 18 meter add on, and all other bands work, it is not the >> feedline... >> >> This makes it simple to fix! It is either a break with the laws of >> physics as we understand them today-- or a connection has come loose. >> Given there are only two connections... I suspect it will be a simple fix. >> >> 73, and thanks, >> Dave (NK7Z) >> https://www.nk7z.net >> ARRL Volunteer Examiner >> ARRL Technical Specialist >> ARRL Asst. Director, NW Division, Technical Resources >> >>> On 9/13/20 4:24 PM, Ken Winterling wrote: >>> When you have issues like this the best test is to use a known good >>> dummy load. That removes the antenna system from the equation. See what >>> happens on 18mHz when transmitting into the summy load. >>> >>> Ken >>> WA2LBI >>> >>> >>> >>> >>> On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> When unpowered the KAT500 is bypassed, ANT1. >>> >>> When the ATU is in mode BYP, yes, it?s bypassed. >>> >>> 73 de Dick, K6KR >>> >>>> On Sep 13, 2020, at 15:52, Dave Cole <[email protected] >>> <mailto:[email protected]>> wrote: >>>> >>>> ?Hello, >>>> My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz., >>> only. Antenna is a single feedline to a 6BTV, and an analyzer says >>> all is good at low power. At 100 watts, all seems good. >>>> >>>> All other bands seem OK at high power. >>>> >>>> Question: When in bypass, is the entire tuner bypassed? >>>> Question: When turned off is the tuner bypassed? Which antenna >>> is default? >>>> -- >>>> 73, and thanks, >>>> Dave (NK7Z) >>>> https://www.nk7z.net >>>> ARRL Volunteer Examiner >>>> ARRL Technical Specialist >>>> ARRL Asst. Director, NW Division, Technical Resources >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] >>> <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] <mailto:[email protected]> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] <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] <mailto:[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] > > > ------------------------------ > > Message: 22 > Date: Mon, 14 Sep 2020 08:10:55 -0700 > From: Nigel Lemaire <[email protected]> > To: [email protected] > Subject: [Elecraft] 630 meter operation on the K4 > Message-ID: <[email protected]> > Content-Type: text/plain; charset=utf-8; format=flowed > > Wondering what capabilities the K4 will have on this (these) bands... > > 73 > Nigel > Wa6MSE > > > ------------------------------ > > Message: 23 > Date: Sun, 13 Sep 2020 22:42:02 -0400 > From: "Charlie T" <[email protected]> > To: <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="UTF-8" > > According to Rob Sherwood, the Collins 32S-3 produces the cleanest SSB signal > on the air of any commercial amateur radio transmitters. > > 73, Charlie k3ICH > > > > > -----Original Message----- > From: [email protected] <[email protected]> On > Behalf Of David Gilbert > Sent: Sunday, September 13, 2020 9:51 PM > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > > > I don't know where you got the idea that the K-Line produces the cleanest > signals. As several people have pointed out, because of the 12 volt finals > the transmit IMD performance of the existing K-line is relatively poor. > > Dave AB7E > > >> On 9/13/2020 2:32 PM, JR wrote: >> Why are so many ops obsessed with predistortion? >> >> The Elecraft K-Line already produces some of the cleanest, purest >> transmit signals around. Do we need predistortion ? If so, why, and >> how much better is it than what we already have? Should I wait to buy >> a new rig until that is available? >> >> Thanks and Happy Trails to all. K8JHR > > ______________________________________________________________ > 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] > > > > ------------------------------ > > Message: 24 > Date: Mon, 14 Sep 2020 07:29:48 -0400 > From: "Charlie T" <[email protected]> > To: <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="UTF-8" > > Maybe I'm missing something here, but it would seem to me that if an FET > linear amplifier running from 50 V or higher is considerably cleaner than > one running from 12 V, that, for a high end rig, a simple step-up switching > supply could solve the problem. But, that obviously adds to the cost so it > IS somewhat of a conundrum. > > However, implementing the pre-distortion function IS probably a better > long-term solution. > > 73, Charlie k3ICH > > > > > -----Original Message----- > From: [email protected] <[email protected]> On > Behalf Of David Gilbert > Sent: Monday, September 14, 2020 12:43 AM > To: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > > > > Of course, but that's a conscious choice by Elecraft and it does not result > in the "cleanest, purest signals around." I give Elecraft tons of credit for > the other measures they have take to produce good signals, which is why I own > and will keep my upgraded K3 probably forever, but K8JHR simply was incorrect > in his comment and it makes a difference when considering the expanding focus > by folks like Sherwood and others to clean up the bands. When it comes to > IMD, Elecraft is not one of the better players. The fact that that's by > choice doesn't change anything. I suspect that 95+% of K3 rigs are used in > portable/emergency situations less than 5% of the time. > > 73, > Dave AB7E > > > >> On 9/13/2020 7:14 PM, Wayne Burdick wrote: >> 12 volts is a severe constraint for MOSFET PAs. But, like a lot of other >> manufacturers, we accept this constraint so the equipment can be used in a >> wide variety of portable/emergency power situations. As a result we have IMD >> numbers in exactly the same range as other products that are subject to this >> constraint. >> >> On the other hand, our transceivers are best in class in terms of >> transmitted keying bandwidth. See paper by K9YC for example. Perhaps that's >> what JR was thinking of. >> >> 73, >> Wayne >> N6KR >> >> >> >>>> On Sep 13, 2020, at 6:50 PM, David Gilbert <[email protected]> wrote: >>> >>> >>> I don't know where you got the idea that the K-Line produces the cleanest >>> signals. As several people have pointed out, because of the 12 volt finals >>> the transmit IMD performance of the existing K-line is relatively poor. >>> >>> Dave AB7E >>> >>> >>> On 9/13/2020 2:32 PM, JR wrote: >>>> Why are so many ops obsessed with predistortion? >>>> >>>> The Elecraft K-Line already produces some of the cleanest, purest transmit >>>> signals around. Do we need predistortion ? If so, why, and how much >>>> better is it than what we already have? Should I wait to buy a new rig >>>> until that is available? >>>> >>>> Thanks and Happy Trails to all. K8JHR >>> ______________________________________________________________ >>> 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] > > > > ------------------------------ > > Message: 25 > Date: Mon, 14 Sep 2020 11:00:25 -0500 > From: "Dr. William J. Schmidt" <[email protected]> > To: "'Elecraft List'" <[email protected]> > Subject: Re: [Elecraft] Why predistortion ? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > 6AU6 - 6CL6 - 6146A trio is a very and associated circuitry produces some of > the lowest distortion products when run at the right conditions (voltages, > etc). Note at 75 watts the 6146 is in its sweet spot. > > > Dr. William J. Schmidt - K9HZ > > > email:? [email protected] > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Charlie T > Sent: Sunday, September 13, 2020 9:42 PM > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > > According to Rob Sherwood, the Collins 32S-3 produces the cleanest SSB > signal on the air of any commercial amateur radio transmitters. > > 73, Charlie k3ICH > > > > > -----Original Message----- > From: [email protected] <[email protected]> On > Behalf Of David Gilbert > Sent: Sunday, September 13, 2020 9:51 PM > To: [email protected] > Subject: Re: [Elecraft] Why predistortion ? > > > I don't know where you got the idea that the K-Line produces the cleanest > signals. As several people have pointed out, because of the 12 volt finals > the transmit IMD performance of the existing K-line is relatively poor. > > Dave AB7E > > >> On 9/13/2020 2:32 PM, JR wrote: >> Why are so many ops obsessed with predistortion? >> >> The Elecraft K-Line already produces some of the cleanest, purest >> transmit signals around. Do we need predistortion ? If so, why, and >> how much better is it than what we already have? Should I wait to buy >> a new rig until that is available? >> >> Thanks and Happy Trails to all. K8JHR > > ______________________________________________________________ > 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] > > > -- > This email has been checked for viruses by AVG. > https://www.avg.com > > > > ------------------------------ > > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > http://mailman.qth.net/mailman/listinfo/elecraft > You must be a subscriber to post. > Elecraft web page: http://www.elecraft.com > > End of Elecraft Digest, Vol 197, Issue 18 > ***************************************** ______________________________________________________________ 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]
