Re: [Elecraft] KPA1500 RFI on 12m
And with that post, lets close this -very- long thread. -Please- self moderate and end discussion threads when they get too long in the interest of relieving email overload for our other readers. Once a thread hits 10 to 15 postings it should be voluntarily ended with very few additional emails. If you feel the need to make additional 'last' comments, please make them off list to direct email. 73, Eric Moderator, from time to time. elecraft.com _..._ > On Oct 29, 2019, at 7:14 PM, Don Wilhelm wrote: > > For all interested, you might want to read the relevant article on my > website www.w3fpr.com. It was written directed at QRP ops, but applies to > QRO operations as well. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
For all interested, you might want to read the relevant article on my
website www.w3fpr.com. It was written directed at QRP ops, but applies
to QRO operations as well.
73,
Don W3FPR
On 10/29/2019 7:56 PM, Bob McGraw K4TAX wrote:
Bill:
Glad to see you post this fact. Hams have had it wrong and doing it
wrong for years, because someone said so. Many hams seem to have less
than zero knowledge on the topic. Oh, less than zero knowledge is
knowledge that is not correct.
Same is true when one uses 450 ohm line, many think they need a 4:1
balun because someone said so. I suppose they believe the "4" in 450
ohm line and the "4" in the 4:1 balun ration have something in
common. Another less than zero knowledge condition.
The electrical length of the wire determines the resonant frequency. Of
course the diameter of the wire contributes to the K factor and bare
wire is different than insulated wire. Thus those two facts must be
considered when cutting an antenna length. Height above ground {not
necessarily earth because of ground conductivity} determines the feed
point impedance.
Oh there is so much to learn about antennas.
73
Bob, K4TAX
On 10/27/2019 9:23 PM, K8TE wrote:
Most hams cut their antenna length for lowest VSWR which is often NOT the
resonant point. Resonance occurs when XsubL equals XsubC. That means
there
is no reactance at one frequency. Impedance varies greatly with height
above ground. The greatest radiation occurs at resonance which,
again, is
often not at the lowest VSWR. This is why a good antenna analyzer that
displays both VSWR and reactance is so helpful.
Web sites abound with advice to cut the antenna for lowest VSWR. Like
politics, the truth is difficult to find and, apparently, often hard to
believe. And, anecdotal statements about how an antenna works
(WORK--WithOut Real Knowledge--K0BG) often has little to do with its
comparative performance. Too few of us use real data (like WSPRLite) to
compare antennas and arrive at conclusions based on comparative data.
I liked the Pacificon theme this year: "The Science of Radio" That
didn't
always apply in some of the presentations, but fortunately did in most I
attended.
73, Bill, K8TE
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Re: [Elecraft] KPA1500 RFI on 12m
Bill:
Glad to see you post this fact. Hams have had it wrong and doing it
wrong for years, because someone said so. Many hams seem to have less
than zero knowledge on the topic. Oh, less than zero knowledge is
knowledge that is not correct.
Same is true when one uses 450 ohm line, many think they need a 4:1
balun because someone said so. I suppose they believe the "4" in 450
ohm line and the "4" in the 4:1 balun ration have something in
common. Another less than zero knowledge condition.
The electrical length of the wire determines the resonant frequency.
Of course the diameter of the wire contributes to the K factor and bare
wire is different than insulated wire. Thus those two facts must be
considered when cutting an antenna length. Height above ground {not
necessarily earth because of ground conductivity} determines the feed
point impedance.
Oh there is so much to learn about antennas.
73
Bob, K4TAX
On 10/27/2019 9:23 PM, K8TE wrote:
Most hams cut their antenna length for lowest VSWR which is often NOT the
resonant point. Resonance occurs when XsubL equals XsubC. That means there
is no reactance at one frequency. Impedance varies greatly with height
above ground. The greatest radiation occurs at resonance which, again, is
often not at the lowest VSWR. This is why a good antenna analyzer that
displays both VSWR and reactance is so helpful.
Web sites abound with advice to cut the antenna for lowest VSWR. Like
politics, the truth is difficult to find and, apparently, often hard to
believe. And, anecdotal statements about how an antenna works
(WORK--WithOut Real Knowledge--K0BG) often has little to do with its
comparative performance. Too few of us use real data (like WSPRLite) to
compare antennas and arrive at conclusions based on comparative data.
I liked the Pacificon theme this year: "The Science of Radio" That didn't
always apply in some of the presentations, but fortunately did in most I
attended.
73, Bill, K8TE
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Re: [Elecraft] KPA1500 RFI on 12m
Most hams cut their antenna length for lowest VSWR which is often NOT the resonant point. Resonance occurs when XsubL equals XsubC. That means there is no reactance at one frequency. Impedance varies greatly with height above ground. The greatest radiation occurs at resonance which, again, is often not at the lowest VSWR. This is why a good antenna analyzer that displays both VSWR and reactance is so helpful. Web sites abound with advice to cut the antenna for lowest VSWR. Like politics, the truth is difficult to find and, apparently, often hard to believe. And, anecdotal statements about how an antenna works (WORK--WithOut Real Knowledge--K0BG) often has little to do with its comparative performance. Too few of us use real data (like WSPRLite) to compare antennas and arrive at conclusions based on comparative data. I liked the Pacificon theme this year: "The Science of Radio" That didn't always apply in some of the presentations, but fortunately did in most I attended. 73, Bill, K8TE -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
Yes, that is the solution. But it shouldn't have to be for an amplifier of the KPA1500's price and class. Further testing shows that on other bands, with an SWR of 1.5 to 2.0, if the tuner is IN, it also goes into random retunes. When the tuner is in BYPASS, the KPA1500 is happy. Also very weird. I never had this problem with KAT500/KPA500 combo on the same antennas, and still don't. I think the KPA1500 firmware needs some tweaking. This is true even when running the KPA1500 at 500w 73 Eric WD6DBM 73 Eric WD6DBM On Fri, Oct 25, 2019, 5:41 AM Dave wrote: > In the KPA1500 utility I have the tuner bypassed for the whole 60 meter > band. The tuner’s logic is detecting a high SWR and overriding the bypass > selection. This happens at 30 watts forward power. > > The answer is to turn off the amp when on 60 and just use the radio’s > tuner. > > Dave wo2x > > Sent from my waxed string and tin cans. > > > On Oct 25, 2019, at 8:17 AM, Andy Durbin wrote: > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to norrislawfi...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
On 10/25/2019 2:01 PM, Bob McGraw K4TAX wrote:
Except for my 6M yagi, all of my antennas are non-resonant antennas. My
favorite is the 256 ft center fed wire {resonant at 1.825 MHz} with a
balanced feed.
Dean Straw, N6BV, retired editor of the ARRL Antenna Book and Antenna
Compendiums, is a very smart engineer and a very good friend. But his
promotion of this sort of antenna is probably the greatest error of his
time in that job, an idea whose time is LONG past, for many reasons.
Primary -- 1) it cannot be choked to kill noise on RX, and 99.9% of hams
live surrounded by local noise and 2) it's pattern is different on every
frequency.
I am a strong believer in resonant antennas for each band, if if the
must be multi-band antennas like fan dipoles to fit in the available
space. For example, a 20/15/10 fan fits in 33 ft and works great, with a
predictable pattern on each band. An 80/40 fan works on 15M, with a
predictable pattern on both 80 and 40. Hypower Antenna company sells
loaded antennas that are resonant on 80 and 40 and fit into about 100
ft; I used one in Chicago on 30 to great effect. All of these antennas
are fed with 50 or 75 ohm coax, and CAN be choked to kill RX noise.
RX noise is a VERY big deal -- if you can't hear 'em, you can't work
'em. If you haven't worked to minimize your RX noise, you're DXing with
one hand tied behind your back! My friend AG6EE goes to remote locations
in NV, OR, and CA to light up rare grids with 1kW on 6M. Folks trying to
work him complain of one-way propagation because he hears them really
well and the don't hear him, but the REAL problem is their local RX noise.
http://k9yc.com/KillingReceiveNoise.pdf Text, NCJ article
http://k9yc.com/KillingRXNoiseVisalia.pdf Slides Visalia talk
73, Jim K9YC
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Re: [Elecraft] KPA1500 RFI on 12m
Except for my 6M yagi, all of my antennas are non-resonant antennas.
My favorite is the 256 ft center fed wire {resonant at 1.825 MHz} with
a balanced feed. The balanced feed runs from the feed-point on the
antenna all the way to the hybrid Guanella 4:1 balun that sits on the
shelf just above the KAT500. The coax jumper from the balun to the
KAT500 is about 12" in length. Thus the balanced line comes in all the
way to the operating position. This configuration will work all
bands, 160M - 6M with ease. And there are NO RFI issues with the KPA500
and the KAT-500 at 500 watts.
I find most hams cut an antenna length by formula, leave a few inches to
trim, and then trim for best SWR. This does not make a resonant
antenna. A resonant antenna is resonant depending on its electrical
length based on frequency. SWR and Impedance should be addressed by
means than trimming the length. Height above ground affects impedance.
73
Bob, K4TAX
On 10/25/2019 3:37 PM, Wes wrote:
Sorry about that mess; that will teach me to try and respond with an
iPhone.
What I was trying to say is that I run a KPA500 and KAT500 into
non-resonant antennas on all of the WARC bands and still manage to
crack pileups. On 12 and 17 meters I tune my tiny OB7-3 Optibeam
tribander. Of the current DXpeditions, I've worked VP6R on 19 slots
and I work FT8 with great reluctance. I've worked 5K0K on 14 of 25
slots without using FT8. For the recently completed ZK3A expedition I
worked them of 24 of 37 slots and was on Clublog's stats number 20 in NA.
I'm pretty sure that I never have the commanding signal in a pileup.
BTW, I use a K3S without a second RX and I don't have a separate RX
antenna for 160, things everybody knows you must have to work DX.
IMHO, knowing how to use the hardware you have is more important than
having more hardware.
Wes N7WS
On 10/25/2019 9:00 AM, Wes N7WS wrote:
I run a KPA500 and KAT500 into an Ppitbe
Sent from my iPhone
On Oct 24, 2019, at 1:24 PM, Michael Walker
wrote:
Hi Eric
I think you are asking a lot for a tuner to run at any power into a
non-resonant antenna and break a pile up. :)
You would actually have better success with a 12M dipole then trying
to get
a non-resonant beam to direct your signal.
If I was in your shoes, I would quickly toss up a 12M dipole with some
string and bubble gum as you would have a much higher radiated signal.
Mike va3mw
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Re: [Elecraft] KPA1500 RFI on 12m
Sorry about that mess; that will teach me to try and respond with an iPhone. What I was trying to say is that I run a KPA500 and KAT500 into non-resonant antennas on all of the WARC bands and still manage to crack pileups. On 12 and 17 meters I tune my tiny OB7-3 Optibeam tribander. Of the current DXpeditions, I've worked VP6R on 19 slots and I work FT8 with great reluctance. I've worked 5K0K on 14 of 25 slots without using FT8. For the recently completed ZK3A expedition I worked them of 24 of 37 slots and was on Clublog's stats number 20 in NA. I'm pretty sure that I never have the commanding signal in a pileup. BTW, I use a K3S without a second RX and I don't have a separate RX antenna for 160, things everybody knows you must have to work DX. IMHO, knowing how to use the hardware you have is more important than having more hardware. Wes N7WS On 10/25/2019 9:00 AM, Wes N7WS wrote: I run a KPA500 and KAT500 into an Ppitbe Sent from my iPhone On Oct 24, 2019, at 1:24 PM, Michael Walker wrote: Hi Eric I think you are asking a lot for a tuner to run at any power into a non-resonant antenna and break a pile up. :) You would actually have better success with a 12M dipole then trying to get a non-resonant beam to direct your signal. If I was in your shoes, I would quickly toss up a 12M dipole with some string and bubble gum as you would have a much higher radiated signal. Mike va3mw __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
I use a C3 up at 80 feet it works quite well. I have not really spent a lot of time on 12m, really no activity here to make it worthwhile but on 17m it works rather well despite not being a particularly good match. I fixed that by measuring the actual impedance at the end of my feeder then adding a foot or so of feeder and cutting a shorted stub to create a good match. In my case it's very close to perfect but anything less than 1.5:1 I would consider excellent. An antenna analyser and 5 minutes with the excellent SimSmith program can do wonders for your matching worries. Properly sorted at just the right point on the feeder with an antenna switch a tee piece and a few stubs you could probably get a good match on a bunch of bands though I suspect the losses might be a bit high if you try 40m, eek! The C3 on 17m certainly has directivity albeit 180 degree from the regular 20-15-10 antenna. Martin, HS0ZED On 25/10/2019 03:08, eric norris via Elecraft wrote: My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the internal atu tunes the antenna fine. Bypassing the K3 atu, but still running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes in and out of TUNE mode uncommanded. Even though the KPA has found a match, trying to transmit through it at the 100w level is impossible because of the constant retuning. I have put my small collection of mix-31 ferrites on the antenna output, input, and KPA control line at the KPA, each at a time, with no success. Any ideas? I would like to be able to run the KPA at least a few hundred watts to have the proverbial snowball's chance to break the VP6R pileup on 12m CW. Any useful comments appreciated. 73 Eric WD6DBM Sent from Yahoo Mail on Android __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to hs0...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
I run a KPA500 and KAT500 into an Ppitbe Sent from my iPhone > On Oct 24, 2019, at 1:24 PM, Michael Walker wrote: > > Hi Eric > > I think you are asking a lot for a tuner to run at any power into a > non-resonant antenna and break a pile up. :) > > You would actually have better success with a 12M dipole then trying to get > a non-resonant beam to direct your signal. > > If I was in your shoes, I would quickly toss up a 12M dipole with some > string and bubble gum as you would have a much higher radiated signal. > > Mike va3mw > > > On Thu, Oct 24, 2019 at 4:08 PM eric norris via Elecraft < > elecraft@mailman.qth.net> wrote: > >> My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the >> internal atu tunes the antenna fine. Bypassing the K3 atu, but still >> running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes >> in and out of TUNE mode uncommanded. Even though the KPA has found a >> match, trying to transmit through it at the 100w level is impossible >> because of the constant retuning. >> I have put my small collection of mix-31 ferrites on the antenna output, >> input, and KPA control line at the KPA, each at a time, with no success. >> Any ideas? I would like to be able to run the KPA at least a few hundred >> watts to have the proverbial snowball's chance to break the VP6R pileup on >> 12m CW. >> Any useful comments appreciated. >> 73 Eric WD6DBM >> >> Sent from Yahoo Mail on Android >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to va...@portcredit.net > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to wes_n...@triconet.org __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
What is a big deal is using the KPA1500 on 60m unless you're using a dummy load or paper clip for an antenna. "The 60 meter band has special restrictions including the restriction of radiated power relative to the gain of a half-wavelength dipole antenna which is 100 watts PEP." We need to keep 60m, not loose it due to abusing its power limit. The KPA1500 tuner can achieve solutions beyond VSWR's of 3:1, but only if running reduced power. See page 18 of the Rev B manual for the VSWR vs. power curve. 73, Bill, K8TE KPA1500 S/N 116 -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
"Not a big deal but there is something weird with the SWR detection in the KPA1500 which allows it to take the amp tuner out of bypass. " It also seems possible that the tuning solution change is triggered by "high SWR threshold". Read the Programming Reference information for commands ^HS; and ^STA; for more info. If this is the cause then setting ^HS0; may help. You will need to use the Utility to inspect and change the values. Sometimes we will accept less than ideal antennas when chasing DX and sometimes we get lucky. Andy, k3wyc __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
In the KPA1500 utility I have the tuner bypassed for the whole 60 meter band. The tuner’s logic is detecting a high SWR and overriding the bypass selection. This happens at 30 watts forward power. The answer is to turn off the amp when on 60 and just use the radio’s tuner. Dave wo2x Sent from my waxed string and tin cans. > On Oct 25, 2019, at 8:17 AM, Andy Durbin wrote: > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 RFI on 12m
"Not a big deal but there is something weird with the SWR detection in the KPA1500 which allows it to take the amp tuner out of bypass. " I don't know the KPA1500 tuner but all the annoying changes in tuning solution of my KAT500 were fixed by defeating RF frequency detection. Is your tuner perhaps selecting an adjacent frequency bin for which the stored solution is not bypass? Andy, k3wyc __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
Hi Eric, What is the measured SWR on 12M? Way different band, worked VP6R 40M CW using K2 at ~15 watts and ground plane 19' vertical. John KN5L On 10/24/19 3:08 PM, eric norris via Elecraft wrote: > Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the > internal atu tunes the antenna fine. Bypassing the K3 atu, but still running > barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes in and > out of TUNE mode uncommanded __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
On 10/24/2019 1:08 PM, eric norris via Elecraft wrote: My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the internal atu tunes the antenna fine. Bypassing the K3 atu, but still running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes in and out of TUNE mode uncommanded. Even though the KPA has found a match, trying to transmit through it at the 100w level is impossible because of the constant retuning. I have put my small collection of mix-31 ferrites on the antenna output, input, and KPA control line at the KPA, each at a time, with no success. Any ideas? Yes. First, and most important, the place for the common mode choke is at the antenna feedpoint, NOT in the shack, and it must be a well-designed multi-turn choke. http://k9yc.com/2018Cookbook.pdf Second, make sure that you entire station is properly bonded, chassis-to-chassis of all interconnected equipment, and that operating desk bonded to every ground in your home. http://k9yc.com/GroundingAndAudio.pdf Also, this is a good time to verify that EVERY coax connector and adapter has its shield well terminated (well soldered or properly crimped) and that all solder-type connectors are an Amphenol 83-1SP. Make sure that all adapters are Amphenol or have a MIL-spec part number stamped on them. Off-brand connectors are often junk, and often cause problems like what you're seeing. Also make sure that every connector is wrench-tight. Station design issues like these may not show up at low power but cause problems with high power. 73, Jim K9YC I would like to be able to run the KPA at least a few hundred watts to have the proverbial snowball's chance to break the VP6R pileup on 12m CW. Any useful comments appreciated. 73 Eric WD6DBM Sent from Yahoo Mail on Android __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to j...@audiosystemsgroup.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
I had a C3SS. From what I remember the amp tuner should be able to handle the SWR. I think the pattern on 12 was 180 degrees from normal heading. Dave wo2x Sent from my iPad > On Oct 24, 2019, at 9:58 PM, j...@kk9a.com wrote: > > I have a C3 that I brought to St Croix and operated as WP2AA. It has no 12m > elements however the manual states it will work on 12m with a tuner although > I am not sure what the pattern would be. I am not a fan of using out of > resonant antennas and do not even have a tuner in any of my K3S's. I wonder > what the C3 SWR is on 12? The KPA1500 specs are for a maximum SWR of 3:1, > perhaps an external tuner is needed? > > John KK9A > > > > eric norris WD6DBM wrote: > > My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the > internal atu tunes the antenna fine. Bypassing the K3 atu, but still > running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes > in and out of TUNE mode uncommanded. Even though the KPA has found a match, > trying to transmit through it at the 100w level is impossible because of the > constant retuning. > I have put my small collection of mix-31 ferrites on the antenna output, > input, and KPA control line at the KPA, each at a time, with no success. > Any ideas? I would like to be able to run the KPA at least a few hundred > watts to have the proverbial snowball's chance to break the VP6R pileup on > 12m CW. > Any useful comments appreciated. > 73 Eric WD6DBM > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to rocke...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
I have a C3 that I brought to St Croix and operated as WP2AA. It has no 12m elements however the manual states it will work on 12m with a tuner although I am not sure what the pattern would be. I am not a fan of using out of resonant antennas and do not even have a tuner in any of my K3S's. I wonder what the C3 SWR is on 12? The KPA1500 specs are for a maximum SWR of 3:1, perhaps an external tuner is needed? John KK9A eric norris WD6DBM wrote: My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the internal atu tunes the antenna fine. Bypassing the K3 atu, but still running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes in and out of TUNE mode uncommanded. Even though the KPA has found a match, trying to transmit through it at the 100w level is impossible because of the constant retuning. I have put my small collection of mix-31 ferrites on the antenna output, input, and KPA control line at the KPA, each at a time, with no success. Any ideas? I would like to be able to run the KPA at least a few hundred watts to have the proverbial snowball's chance to break the VP6R pileup on 12m CW. Any useful comments appreciated. 73 Eric WD6DBM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
I have similar weirdness on 60 meters using the tuner in the radio with the amp in standby and amp tuner bypassed. The amp wattmeter shows 276 watts reflected and the amp tuner keeps trying to automatically engage. Something in the amp logic will not allow it to be in pass through but after the radio tuner. I have to have the amp off when running 60 meters. Not a big deal but there is something weird with the SWR detection in the KPA1500 which allows it to take the amp tuner out of bypass. Dave wo2x Sent from my waxed string and tin cans. > On Oct 24, 2019, at 4:26 PM, Michael Walker wrote: > > Hi Eric > > I think you are asking a lot for a tuner to run at any power into a > non-resonant antenna and break a pile up. :) > > You would actually have better success with a 12M dipole then trying to get > a non-resonant beam to direct your signal. > > If I was in your shoes, I would quickly toss up a 12M dipole with some > string and bubble gum as you would have a much higher radiated signal. > > Mike va3mw > > >> On Thu, Oct 24, 2019 at 4:08 PM eric norris via Elecraft < >> elecraft@mailman.qth.net> wrote: >> >> My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the >> internal atu tunes the antenna fine. Bypassing the K3 atu, but still >> running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes >> in and out of TUNE mode uncommanded. Even though the KPA has found a >> match, trying to transmit through it at the 100w level is impossible >> because of the constant retuning. >> I have put my small collection of mix-31 ferrites on the antenna output, >> input, and KPA control line at the KPA, each at a time, with no success. >> Any ideas? I would like to be able to run the KPA at least a few hundred >> watts to have the proverbial snowball's chance to break the VP6R pileup on >> 12m CW. >> Any useful comments appreciated. >> 73 Eric WD6DBM >> >> Sent from Yahoo Mail on Android >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to va...@portcredit.net > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to rocke...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 12m
Hi Eric I think you are asking a lot for a tuner to run at any power into a non-resonant antenna and break a pile up. :) You would actually have better success with a 12M dipole then trying to get a non-resonant beam to direct your signal. If I was in your shoes, I would quickly toss up a 12M dipole with some string and bubble gum as you would have a much higher radiated signal. Mike va3mw On Thu, Oct 24, 2019 at 4:08 PM eric norris via Elecraft < elecraft@mailman.qth.net> wrote: > My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the > internal atu tunes the antenna fine. Bypassing the K3 atu, but still > running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes > in and out of TUNE mode uncommanded. Even though the KPA has found a > match, trying to transmit through it at the 100w level is impossible > because of the constant retuning. > I have put my small collection of mix-31 ferrites on the antenna output, > input, and KPA control line at the KPA, each at a time, with no success. > Any ideas? I would like to be able to run the KPA at least a few hundred > watts to have the proverbial snowball's chance to break the VP6R pileup on > 12m CW. > Any useful comments appreciated. > 73 Eric WD6DBM > > Sent from Yahoo Mail on Android > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to va...@portcredit.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 RFI on 12m
My Force 12 C3 antenna is not resonant on 12m. Using the K3 barefoot, the internal atu tunes the antenna fine. Bypassing the K3 atu, but still running barefoot into the KPA1500 atu, the KPA atu loses it's mind and goes in and out of TUNE mode uncommanded. Even though the KPA has found a match, trying to transmit through it at the 100w level is impossible because of the constant retuning. I have put my small collection of mix-31 ferrites on the antenna output, input, and KPA control line at the KPA, each at a time, with no success. Any ideas? I would like to be able to run the KPA at least a few hundred watts to have the proverbial snowball's chance to break the VP6R pileup on 12m CW. Any useful comments appreciated. 73 Eric WD6DBM Sent from Yahoo Mail on Android __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
