Re: [Elecraft] Is a K3 ATU with balanced outputs possible?
Put the balun outside and bring the coax into the shack. I am feeding a large NVIS loop with my K3. The loop is fed with 450 ohm window line which connects to a 4:1 balun under the eve of the roof before it enters the shack. The K3 is connected to the balun with 50 ohm coax. My K3 tuner will match the load from 160 to 10 meters. When running the KPA500 I use a large 2000W tuner. Aword of caution: Make sure your window/ladder line does not touch the house anywhere. It could start a fire. Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member On Fri, 28 Sep 2012 19:06:36 -0400, Andrew Moore wrote: >Great; thank you for the trivia, very helpful. I figured it had already >been considered and that there was a good reason for the current >configuration. > >The BL2 following the KAT3 was exactly one option I was considering. I've >read about several cases in which ops had success, but read others in which >the balun was heating perhaps due to excessive reactance on the antenna >side. Reactance is likely dependent on the frequency/band and several >factors in the antenna system which could explain the mixed results. > >I think I will try this approach and enjoy the experimenting. > >All: Not looking to turn this in to an OT antenna theory thread, but if you >have specific experience with this configuration, I'd like to hear (KAT3 to >BL2 to ladder to simple dipole). > >Thanks, >--Andrew, NV1B >maineware.net >.. > > >On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: > >> Andrew, >> >> A bit of 'trivia' first: >> That was "supposed" to be a solution in the KAT500 tuner. The initial >> design put the balun on the input of the tuner, and attempted to "float" >> the rest of the tuner while trying to maintain balance. >> >> There were problems with maintaining balance through the rest of the >> tuner, while studies indicated there was no efficiency difference between >> the balun at the input vs. the balun at the output, so the design was >> changed to an unbalanced design driving (if required or desired) a balun at >> the output of the tuner. >> >> "trivia off": >> >> So more specific to your question, a balanced output from the K3 KAT3 can >> easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >> >> >__ >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 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] Is a K3 ATU with balanced outputs possible?
Bob, My analysis - while "floating the unbalanced tuner" may be possible in theory, in practice, it is not practical. There are always be points that will be found to upset the balance. There is a reason for creating balanced networks, and putting the balun on the input of an unbalanced network is just not one of them. The bottom line is found at the end of the W8JI article. "Moving the balun to the input is only helpful when the balun is not needed". So use the KAT100 or KAT500 as designed and put a balun on the output if you must use balanced feed. 73, Don W3FPR On 9/28/2012 9:47 PM, Bob Cunnings wrote: > Maybe not. The analysis presented in this article: > > http://fermi.la.asu.edu/w9cf/articles/balun/ > > leads to the conclusion that locating the choke balun at the input of > the tuner, and floating the tuner, offers an advantage only for > balanced tuner designs (and good balance in the load). The stress on > the balun in a high SWR situation is unchanged by moving it to the > input. In short "An unbalanced tuner trades the large differential > mode impedance for a large unbalanced impedance making the balun's job > unchanged." > > W8JI also addresses the issue in this article: > > http://www.w8ji.com/tuner_baluns.htm > > and comes to the same conclusion, with emphasis on the need for good > load balance in the case of a balanced tuner with choke balun at the > input. He ends with: "The irony is, moving the balun to the input > mostly works only when the balun is not needed!". > > Food for thought. > > I use a floating balanced-L tuner with choke balun at the input, but > try to keep decent balance in the antenna system for this reason. > > Bob NW8L > >> There may be no difference in efficiency between putting the balun at the >> input >> or the output of the tuner if you are operating into a nice 50ohm resistive >> dummy load, but the situation changes if you are operating into an antenna >> fed >> with ladder line on which there is a high SWR. In this case, the high SWR can >> cause high currents that saturate the ferrite core in the balun, and causing >> non-linearity and producing heat losses. This is why it may be preferable to >> locate the balun at the input of the tuner, where the SWR on the transmission >> line is low, and "float" the whole tuner. However, as Don mentioned, this can >> present difficulties if the tuner is not a balanced design. >> >> 73, Matt VK2ACL > __ > 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 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] Is a K3 ATU with balanced outputs possible?
Hi Don & all, Yes the reason for the length of 285 Ft is based on reading Cebick's musings in antennix on long wire anenna's / V beams & on to Rhombic antenna's, where Cebick notes that odd multiples of 1/4 wavelength produce slightly more gain than multiples of 1/2 wavelength. I think that I stumbled upon some serendipity with the 285Ft length cause it sure works! All noted re the Bi-directionality, I considered it not worth the aggrivation & trouble to terminate the wires thats for sure. 73 from, Eric Buggee, VK3AX. On 9/29/2012 10:22 AM, Don Wilhelm wrote: > Eric, > > A "V" beam will be quite directional (bidirectional) and the response > depends on frequency. especially at those frequencies where the length > is in excess of 1 wavelength. > > You must have found a good length if it operates well with the BL2 and > the KAT3 combination. > The wire angle of 70 degrees is good for 40 meters through 20 meters, > but is effective for other bands as well. > > 73, > Don W3FPR > > On 9/28/2012 8:04 PM, Eric Buggee wrote: >> Hi Andrew, Don & all, >> >> I have a K3 (4520) and have recently installed a new antenna in the form >> of a "V" beam with the bisector at about 7 Degrees east of North, with >> the included angle at about 70 degrees and a leg length of 285Ft, height >> above ground is 70 to 75 Ft, with ground sloping down away to N & NE for >> 20Km. >> >> I have found that using the KAT3 in the K3 and a BL2 Balun it is useable >> on all bands from 160 through to 6M with the worst VSWR of 1.5:1 showing >> up on 160 at 1860KHz. >> >> Reports from stations at, 1 to 5000 Km north from Emerald in the ranges >> 60 KM East of Melbourne in VK3 land give the "V" beam an advantage of 2 >> to 3 Sunits over the main antenna running NE to SW (A full sized 160M >> dipole at 105Ft, fed with OW line spced 6inches) . >> >> Reports run as follows:- 160M, generally 1 S unit down WR to the 160M >> dipole; >> >> 80M, equal to & sometimes 1 S unit better (on average) compared to the >> 160 M dipole appears to be dependent upon time of day & prop'n >> conditions; >> >> 40M, definitely better with 1 to 2 S units better most of the time (day >> or night); >> >> 30 M, definitely better by consistent 2 to 3 Sunits better at 3 to >> 5000Km; >> >> 20 M like 30 M consistently better than the 160 M dipole by 2 to 3 S >> units at 3 to 5000Km distance. >> >> The higher bands, with the V Beam I am hearing DX stations that are not >> even detectable on the 160 M dipole (8 & 24MHz), but, so far no >> definitive contacts made using the V beam to give a real evalution as >> yet. It has only been operational for about 10 days. >> >> Hope the foregoing is of interest, >> >> 73, >> >> From Eric VK3AX. >> >> >> >> On 9/29/2012 9:06 AM, Andrew Moore wrote: >>> Great; thank you for the trivia, very helpful. I figured it had already >>> been considered and that there was a good reason for the current >>> configuration. >>> >>> The BL2 following the KAT3 was exactly one option I was considering. >>> I've >>> read about several cases in which ops had success, but read others >>> in which >>> the balun was heating perhaps due to excessive reactance on the antenna >>> side. Reactance is likely dependent on the frequency/band and several >>> factors in the antenna system which could explain the mixed results. >>> >>> I think I will try this approach and enjoy the experimenting. >>> >>> All: Not looking to turn this in to an OT antenna theory thread, but >>> if you >>> have specific experience with this configuration, I'd like to hear >>> (KAT3 to >>> BL2 to ladder to simple dipole). >>> >>> Thanks, >>> --Andrew, NV1B >>> maineware.net >>> .. >>> >>> >>> On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm >>> wrote: >>> Andrew, A bit of 'trivia' first: That was "supposed" to be a solution in the KAT500 tuner. The initial design put the balun on the input of the tuner, and attempted to "float" the rest of the tuner while trying to maintain balance. There were problems with maintaining balance through the rest of the tuner, while studies indicated there was no efficiency difference between the balun at the input vs. the balun at the output, so the design was changed to an unbalanced design driving (if required or desired) a balun at the output of the tuner. "trivia off": So more specific to your question, a balanced output from the K3 KAT3 can easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >>> __ >>> 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] Is a K3 ATU with balanced outputs possible?
Maybe not. The analysis presented in this article: http://fermi.la.asu.edu/w9cf/articles/balun/ leads to the conclusion that locating the choke balun at the input of the tuner, and floating the tuner, offers an advantage only for balanced tuner designs (and good balance in the load). The stress on the balun in a high SWR situation is unchanged by moving it to the input. In short "An unbalanced tuner trades the large differential mode impedance for a large unbalanced impedance making the balun's job unchanged." W8JI also addresses the issue in this article: http://www.w8ji.com/tuner_baluns.htm and comes to the same conclusion, with emphasis on the need for good load balance in the case of a balanced tuner with choke balun at the input. He ends with: "The irony is, moving the balun to the input mostly works only when the balun is not needed!". Food for thought. I use a floating balanced-L tuner with choke balun at the input, but try to keep decent balance in the antenna system for this reason. Bob NW8L >There may be no difference in efficiency between putting the balun at the input >or the output of the tuner if you are operating into a nice 50ohm resistive >dummy load, but the situation changes if you are operating into an antenna fed >with ladder line on which there is a high SWR. In this case, the high SWR can >cause high currents that saturate the ferrite core in the balun, and causing >non-linearity and producing heat losses. This is why it may be preferable to >locate the balun at the input of the tuner, where the SWR on the transmission >line is low, and "float" the whole tuner. However, as Don mentioned, this can >present difficulties if the tuner is not a balanced design. > >73, Matt VK2ACL __ 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] Is a K3 ATU with balanced outputs possible?
* On 2012 28 Sep 18:07 -0500, Andrew Moore wrote: > I think I will try this approach and enjoy the experimenting. Hi Andrew. For learning the theory on a lot of this stuff, a good reference on the topic is Reflections III by Walt Maxwell, W2DU (SK), published by CQ Communications. Walt did a very good job explaining the 'what' and 'why' on impedance matching and also some gave some 'how' on dealing with it in a practical manner. The book has its roots in a series of articles he wrote in the '70s for QST titled, "Another Look at Reflections" and the series can be found on the ARRL's QST archive. I have the first edition but procrastinated and never got the second edition published by World Radio, now owned by CQ. 73, de Nate, N0NB >> -- "The optimist proclaims that we live in the best of all possible worlds. The pessimist fears this is true." Ham radio, Linux, bikes, and more: http://www.n0nb.us __ 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] Is a K3 ATU with balanced outputs possible?
Eric, A "V" beam will be quite directional (bidirectional) and the response depends on frequency. especially at those frequencies where the length is in excess of 1 wavelength. You must have found a good length if it operates well with the BL2 and the KAT3 combination. The wire angle of 70 degrees is good for 40 meters through 20 meters, but is effective for other bands as well. 73, Don W3FPR On 9/28/2012 8:04 PM, Eric Buggee wrote: > Hi Andrew, Don & all, > > I have a K3 (4520) and have recently installed a new antenna in the form > of a "V" beam with the bisector at about 7 Degrees east of North, with > the included angle at about 70 degrees and a leg length of 285Ft, height > above ground is 70 to 75 Ft, with ground sloping down away to N & NE for > 20Km. > > I have found that using the KAT3 in the K3 and a BL2 Balun it is useable > on all bands from 160 through to 6M with the worst VSWR of 1.5:1 showing > up on 160 at 1860KHz. > > Reports from stations at, 1 to 5000 Km north from Emerald in the ranges > 60 KM East of Melbourne in VK3 land give the "V" beam an advantage of 2 > to 3 Sunits over the main antenna running NE to SW (A full sized 160M > dipole at 105Ft, fed with OW line spced 6inches) . > > Reports run as follows:- 160M, generally 1 S unit down WR to the 160M > dipole; > > 80M, equal to & sometimes 1 S unit better (on average) compared to the > 160 M dipole appears to be dependent upon time of day & prop'n conditions; > > 40M, definitely better with 1 to 2 S units better most of the time (day > or night); > > 30 M, definitely better by consistent 2 to 3 Sunits better at 3 to 5000Km; > > 20 M like 30 M consistently better than the 160 M dipole by 2 to 3 S > units at 3 to 5000Km distance. > > The higher bands, with the V Beam I am hearing DX stations that are not > even detectable on the 160 M dipole (8 & 24MHz), but, so far no > definitive contacts made using the V beam to give a real evalution as > yet. It has only been operational for about 10 days. > > Hope the foregoing is of interest, > > 73, > > From Eric VK3AX. > > > > On 9/29/2012 9:06 AM, Andrew Moore wrote: >> Great; thank you for the trivia, very helpful. I figured it had already >> been considered and that there was a good reason for the current >> configuration. >> >> The BL2 following the KAT3 was exactly one option I was considering. I've >> read about several cases in which ops had success, but read others in which >> the balun was heating perhaps due to excessive reactance on the antenna >> side. Reactance is likely dependent on the frequency/band and several >> factors in the antenna system which could explain the mixed results. >> >> I think I will try this approach and enjoy the experimenting. >> >> All: Not looking to turn this in to an OT antenna theory thread, but if you >> have specific experience with this configuration, I'd like to hear (KAT3 to >> BL2 to ladder to simple dipole). >> >> Thanks, >> --Andrew, NV1B >> maineware.net >> .. >> >> >> On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: >> >>> Andrew, >>> >>> A bit of 'trivia' first: >>> That was "supposed" to be a solution in the KAT500 tuner. The initial >>> design put the balun on the input of the tuner, and attempted to "float" >>> the rest of the tuner while trying to maintain balance. >>> >>> There were problems with maintaining balance through the rest of the >>> tuner, while studies indicated there was no efficiency difference between >>> the balun at the input vs. the balun at the output, so the design was >>> changed to an unbalanced design driving (if required or desired) a balun at >>> the output of the tuner. >>> >>> "trivia off": >>> >>> So more specific to your question, a balanced output from the K3 KAT3 can >>> easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >>> >>> >> __ >> 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 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 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] Is a K3 ATU with balanced outputs possible?
On 9/29/2012 10:04 AM, Eric Buggee wrote: Addendum to my original post. > Hi Andrew, Don & all, > > I have a K3 (4520) and have recently installed a new antenna in the > form of a "V" beam with the bisector at about 7 Degrees east of North, > with the included angle at about 70 degrees and a leg length of 285Ft, > height above ground is 70 to 75 Ft, with ground sloping down away to N > & NE for 20Km. " I should have added: the following". " The feed line from the BL2 which is mounted under the eaves of the shack with about 3M of RG58 to the K3. From the BL2 at 10Ft above ground to the V beam I have a run of 73Ft of Ladder Line with 14Gauge Copperweld conductors." > > I have found that using the KAT3 in the K3 and the BL2 Balun it is > useable on all bands from 160 through to 6M with the worst VSWR of > 1.5:1 showing up on 160 at 1860KHz. > > Reports from stations at, 1 to 5000 Km north from Emerald in the > ranges 60 KM East of Melbourne in VK3 land give the "V" beam an > advantage of 2 to 3 Sunits over the main antenna running NE to SW (A > full sized 160M dipole at 105Ft, fed with OW line spced 6inches) . > > Reports run as follows:- 160M, generally 1 S unit down WR to the 160M > dipole; > > 80M, equal to & sometimes 1 S unit better (on average) compared to the > 160 M dipole appears to be dependent upon time of day & prop'n > conditions; > > 40M, definitely better with 1 to 2 S units better most of the time > (day or night); > > 30 M, definitely better by consistent 2 to 3 Sunits better at 3 to > 5000Km; > > 20 M like 30 M consistently better than the 160 M dipole by 2 to 3 S > units at 3 to 5000Km distance. > > The higher bands, with the V Beam I am hearing DX stations that are > not even detectable on the 160 M dipole (8 & 24MHz), but, so far no > definitive contacts made using the V beam to give a real evalution as > yet. It has only been operational for about 10 days. > > Hope the foregoing is of interest, > > 73, > > From Eric VK3AX. > > > > On 9/29/2012 9:06 AM, Andrew Moore wrote: >> Great; thank you for the trivia, very helpful. I figured it had already >> been considered and that there was a good reason for the current >> configuration. >> >> The BL2 following the KAT3 was exactly one option I was considering. >> I've >> read about several cases in which ops had success, but read others in >> which >> the balun was heating perhaps due to excessive reactance on the antenna >> side. Reactance is likely dependent on the frequency/band and several >> factors in the antenna system which could explain the mixed results. >> >> I think I will try this approach and enjoy the experimenting. >> >> All: Not looking to turn this in to an OT antenna theory thread, but >> if you >> have specific experience with this configuration, I'd like to hear >> (KAT3 to >> BL2 to ladder to simple dipole). >> >> Thanks, >> --Andrew, NV1B >> maineware.net >> .. >> >> >> On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm >> wrote: >> >>> Andrew, >>> >>> A bit of 'trivia' first: >>> That was "supposed" to be a solution in the KAT500 tuner. The initial >>> design put the balun on the input of the tuner, and attempted to >>> "float" >>> the rest of the tuner while trying to maintain balance. >>> >>> There were problems with maintaining balance through the rest of the >>> tuner, while studies indicated there was no efficiency difference >>> between >>> the balun at the input vs. the balun at the output, so the design was >>> changed to an unbalanced design driving (if required or desired) a >>> balun at >>> the output of the tuner. >>> >>> "trivia off": >>> >>> So more specific to your question, a balanced output from the K3 >>> KAT3 can >>> easily be obtained by using an Elecraft BL2 on the output side of >>> the KAT3. >>> >>> >> __ >> 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 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] Is a K3 ATU with balanced outputs possible?
Hi Andrew, Don & all, I have a K3 (4520) and have recently installed a new antenna in the form of a "V" beam with the bisector at about 7 Degrees east of North, with the included angle at about 70 degrees and a leg length of 285Ft, height above ground is 70 to 75 Ft, with ground sloping down away to N & NE for 20Km. I have found that using the KAT3 in the K3 and a BL2 Balun it is useable on all bands from 160 through to 6M with the worst VSWR of 1.5:1 showing up on 160 at 1860KHz. Reports from stations at, 1 to 5000 Km north from Emerald in the ranges 60 KM East of Melbourne in VK3 land give the "V" beam an advantage of 2 to 3 Sunits over the main antenna running NE to SW (A full sized 160M dipole at 105Ft, fed with OW line spced 6inches) . Reports run as follows:- 160M, generally 1 S unit down WR to the 160M dipole; 80M, equal to & sometimes 1 S unit better (on average) compared to the 160 M dipole appears to be dependent upon time of day & prop'n conditions; 40M, definitely better with 1 to 2 S units better most of the time (day or night); 30 M, definitely better by consistent 2 to 3 Sunits better at 3 to 5000Km; 20 M like 30 M consistently better than the 160 M dipole by 2 to 3 S units at 3 to 5000Km distance. The higher bands, with the V Beam I am hearing DX stations that are not even detectable on the 160 M dipole (8 & 24MHz), but, so far no definitive contacts made using the V beam to give a real evalution as yet. It has only been operational for about 10 days. Hope the foregoing is of interest, 73, From Eric VK3AX. On 9/29/2012 9:06 AM, Andrew Moore wrote: > Great; thank you for the trivia, very helpful. I figured it had already > been considered and that there was a good reason for the current > configuration. > > The BL2 following the KAT3 was exactly one option I was considering. I've > read about several cases in which ops had success, but read others in which > the balun was heating perhaps due to excessive reactance on the antenna > side. Reactance is likely dependent on the frequency/band and several > factors in the antenna system which could explain the mixed results. > > I think I will try this approach and enjoy the experimenting. > > All: Not looking to turn this in to an OT antenna theory thread, but if you > have specific experience with this configuration, I'd like to hear (KAT3 to > BL2 to ladder to simple dipole). > > Thanks, > --Andrew, NV1B > maineware.net > .. > > > On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: > >> Andrew, >> >> A bit of 'trivia' first: >> That was "supposed" to be a solution in the KAT500 tuner. The initial >> design put the balun on the input of the tuner, and attempted to "float" >> the rest of the tuner while trying to maintain balance. >> >> There were problems with maintaining balance through the rest of the >> tuner, while studies indicated there was no efficiency difference between >> the balun at the input vs. the balun at the output, so the design was >> changed to an unbalanced design driving (if required or desired) a balun at >> the output of the tuner. >> >> "trivia off": >> >> So more specific to your question, a balanced output from the K3 KAT3 can >> easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >> >> > __ > 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 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] Is a K3 ATU with balanced outputs possible?
Andrew, The BL2 on the output of the tuner may not be the total answer. The conditions and situations are too numerous to address. I would suggest some study into antennas and transmission lines before assuming that "anything will work" - because it is not true that "anything will work". The one thing I can say is that if you can make an antenna take a load, that power will be radiated. Beyond that statement, I take no responsibility for the specifics, it all depends on the particular installation. As one "for instance", attempting to feed the end of a 1/2 wavelength wire will likely result in failure. The KAT3 is not designed to work into a quite high impedance. 73. Don W3FPR On 9/28/2012 7:06 PM, Andrew Moore wrote: > Great; thank you for the trivia, very helpful. I figured it had already > been considered and that there was a good reason for the current > configuration. > > The BL2 following the KAT3 was exactly one option I was considering. I've > read about several cases in which ops had success, but read others in which > the balun was heating perhaps due to excessive reactance on the antenna > side. Reactance is likely dependent on the frequency/band and several > factors in the antenna system which could explain the mixed results. > > I think I will try this approach and enjoy the experimenting. > > All: Not looking to turn this in to an OT antenna theory thread, but if you > have specific experience with this configuration, I'd like to hear (KAT3 to > BL2 to ladder to simple dipole). > > Thanks, > --Andrew, NV1B > maineware.net > .. > > > On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: > >> Andrew, >> >> A bit of 'trivia' first: >> That was "supposed" to be a solution in the KAT500 tuner. The initial >> design put the balun on the input of the tuner, and attempted to "float" >> the rest of the tuner while trying to maintain balance. >> >> There were problems with maintaining balance through the rest of the >> tuner, while studies indicated there was no efficiency difference between >> the balun at the input vs. the balun at the output, so the design was >> changed to an unbalanced design driving (if required or desired) a balun at >> the output of the tuner. >> >> "trivia off": >> >> So more specific to your question, a balanced output from the K3 KAT3 can >> easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >> >> > __ > 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 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] Is a K3 ATU with balanced outputs possible?
There may be no difference in efficiency between putting the balun at the input or the output of the tuner if you are operating into a nice 50ohm resistive dummy load, but the situation changes if you are operating into an antenna fed with ladder line on which there is a high SWR. In this case, the high SWR can cause high currents that saturate the ferrite core in the balun, and causing non-linearity and producing heat losses. This is why it may be preferable to locate the balun at the input of the tuner, where the SWR on the transmission line is low, and "float" the whole tuner. However, as Don mentioned, this can present difficulties if the tuner is not a balanced design. 73, Matt VK2ACL On 29/09/2012, at 9:06 AM, Andrew Moore wrote: > Great; thank you for the trivia, very helpful. I figured it had already > been considered and that there was a good reason for the current > configuration. > > The BL2 following the KAT3 was exactly one option I was considering. I've > read about several cases in which ops had success, but read others in which > the balun was heating perhaps due to excessive reactance on the antenna > side. Reactance is likely dependent on the frequency/band and several > factors in the antenna system which could explain the mixed results. > > I think I will try this approach and enjoy the experimenting. > > All: Not looking to turn this in to an OT antenna theory thread, but if you > have specific experience with this configuration, I'd like to hear (KAT3 to > BL2 to ladder to simple dipole). > > Thanks, > --Andrew, NV1B > maineware.net > .. > > > On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: > >> Andrew, >> >> A bit of 'trivia' first: >> That was "supposed" to be a solution in the KAT500 tuner. The initial >> design put the balun on the input of the tuner, and attempted to "float" >> the rest of the tuner while trying to maintain balance. >> >> There were problems with maintaining balance through the rest of the >> tuner, while studies indicated there was no efficiency difference between >> the balun at the input vs. the balun at the output, so the design was >> changed to an unbalanced design driving (if required or desired) a balun at >> the output of the tuner. >> >> "trivia off": >> >> So more specific to your question, a balanced output from the K3 KAT3 can >> easily be obtained by using an Elecraft BL2 on the output side of the KAT3. >> >> > __ > 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 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] Is a K3 ATU with balanced outputs possible?
Great; thank you for the trivia, very helpful. I figured it had already been considered and that there was a good reason for the current configuration. The BL2 following the KAT3 was exactly one option I was considering. I've read about several cases in which ops had success, but read others in which the balun was heating perhaps due to excessive reactance on the antenna side. Reactance is likely dependent on the frequency/band and several factors in the antenna system which could explain the mixed results. I think I will try this approach and enjoy the experimenting. All: Not looking to turn this in to an OT antenna theory thread, but if you have specific experience with this configuration, I'd like to hear (KAT3 to BL2 to ladder to simple dipole). Thanks, --Andrew, NV1B maineware.net .. On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm wrote: > Andrew, > > A bit of 'trivia' first: > That was "supposed" to be a solution in the KAT500 tuner. The initial > design put the balun on the input of the tuner, and attempted to "float" > the rest of the tuner while trying to maintain balance. > > There were problems with maintaining balance through the rest of the > tuner, while studies indicated there was no efficiency difference between > the balun at the input vs. the balun at the output, so the design was > changed to an unbalanced design driving (if required or desired) a balun at > the output of the tuner. > > "trivia off": > > So more specific to your question, a balanced output from the K3 KAT3 can > easily be obtained by using an Elecraft BL2 on the output side of the KAT3. > > __ 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] Is a K3 ATU with balanced outputs possible?
Andrew, A bit of 'trivia' first: That was "supposed" to be a solution in the KAT500 tuner. The initial design put the balun on the input of the tuner, and attempted to "float" the rest of the tuner while trying to maintain balance. There were problems with maintaining balance through the rest of the tuner, while studies indicated there was no efficiency difference between the balun at the input vs. the balun at the output, so the design was changed to an unbalanced design driving (if required or desired) a balun at the output of the tuner. "trivia off": So more specific to your question, a balanced output from the K3 KAT3 can easily be obtained by using an Elecraft BL2 on the output side of the KAT3. 73, Don W3FPR On 9/28/2012 6:22 PM, Andrew Moore wrote: > I'd love to see a K3 built-in ATU with balanced outputs to feed "ladder" > line. Has this been considered and dismissed, or is it a possibility for a > future option? > > I'm guessing this might be a problem for the already crowded rear panel, > but could it be provided as a plug-in board (like the KANT3 or the KAT3) > that uses the two antenna ports (ANT1, ANT2) for the two sides of the > ladder line, and does away with the SO239 altogether? > > Failing that, could the functionality be provided in the KAT500? > > Apologies if this has already been discussed; I haven't found much > discussion on it in the archives. > __ 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
