Re: [Elecraft] KAT500 tuning behavior when the load is impossible to match ?
It's easier with a tuner that has lossy components. It's really easy with a tee tuner with three adjustable components. There are many matching solutions, only one of them is the lowest loss. On 4/2/2017 2:12 PM, Don Wilhelm wrote: Phil, It is indeed possible to match a very high SWR or even an open circuit or a short. That will be more probable on the higher frequency bands than on the lower bands. 73, Don W3FPR __ 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] KAT500 tuning behavior when the load is impossible to match ?
To answer your other question, if the KAT500 cannot find a match better than 1.5:1 the FAULT indicator on the front panel will light. You will also trigger a fault if: 1) The RF power is above 110 watts while tuning to protect the relays from arcing. 2) The impedance can be matched but is outside of the KAT500's normal tuning range with an impedance that may produce RF voltages that could damage the components considering the RF power applied. In that case, the fault occurs when you raise the RF power. However, it is safe to operate at any power level below which the fault occurs. 73, Ron AC7AC -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Sunday, April 2, 2017 2:12 PM To: Phil Hystad; Elecraft Reflector Subject: Re: [Elecraft] KAT500 tuning behavior when the load is impossible to match ? Phil, It is indeed possible to match a very high SWR or even an open circuit or a short. That will be more probable on the higher frequency bands than on the lower bands. 73, Don W3FPR On 4/2/2017 12:42 PM, Phil Hystad wrote: > I got my second KAT500 tuner to use with my new backup rig and while setting up and testing and tuning with my two different antennas I made a mistake. > > I first observed the results displayed on the utility program operate page where the tuned SWR was 1:1 and the bypass SWR was something like 54:1. I immediately realized that something was not right and discovered that my coax cable was not switched to the antenna but rather my dummy load but the cable to the dummy load was disconnected (because I was moving things around). > __ 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 r...@elecraft.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] KAT500 tuning behavior when the load is impossible to match ?
Phil, It is indeed possible to match a very high SWR or even an open circuit or a short. That will be more probable on the higher frequency bands than on the lower bands. 73, Don W3FPR On 4/2/2017 12:42 PM, Phil Hystad wrote: I got my second KAT500 tuner to use with my new backup rig and while setting up and testing and tuning with my two different antennas I made a mistake. I first observed the results displayed on the utility program operate page where the tuned SWR was 1:1 and the bypass SWR was something like 54:1. I immediately realized that something was not right and discovered that my coax cable was not switched to the antenna but rather my dummy load but the cable to the dummy load was disconnected (because I was moving things around). __ 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] KAT500 tuning behavior when the load is impossible to match ?
Your story reminds me of a scene from that Godzilla movie with Matthew Broderick where he is “pumping” over sized worms from the ground using electricity. 73, phil, K7PEH > On Apr 2, 2017, at 10:05 AM, Mike Rhodes wrote: > > No practical experience with the KAT500 but can tell you that, years ago, > while guest operation at a contest station, a 160 meter vertical was strung > up between a couple of the towers. The operator went in and successfully > tuned the antenna to a 1:1 match and then loaded the KW amp to full output. > He then went S&P to get warmed up but heard very little and could not work > any of the few stations he did hear. We went out and discovered that the > vertical wire had snagged on the ground rod! The tuner was manual but imagine > the same principal applies. Yes, you can often get a "perfect" match but that > may not count for much! Have often wondered if the earth worm population in > that area ever recovered. > > Mike / W8DN > > On 4/2/2017 12:42 PM, Phil Hystad wrote: >> I got my second KAT500 tuner to use with my new backup rig and while setting >> up and testing and tuning with my two different antennas I made a mistake. >> >> I first observed the results displayed on the utility program operate page >> where the tuned SWR was 1:1 and the bypass SWR was something like 54:1. I >> immediately realized that something was not right and discovered that my >> coax cable was not switched to the antenna but rather my dummy load but the >> cable to the dummy load was disconnected (because I was moving things >> around). >> >> OK, fixed that little problem but I was curious about the behavior when the >> KAT500 tuner is faced with an impossible match. Does it give up? I assume >> it gives up but then I didn’t see anything to indicate that the tuning >> operation gave up. In fact, it seemed like it found a tuned LC solution but >> one that was matched with a bypass of 54:1. >> >> My first question: If KAT500 fails to find a valid solution does it report >> an error. I ask this because at times I have had red LED lights flashing on >> a failed tune but I did not have one this time. I am wondering if I missed >> the error report on the utility program. >> >> My second question: Is it possible that the KAT500 did resolve a tuned LC >> solution with basically 6 feet of coaxial cable unconnected with anything? >> >> Thanks, >> >> 73, phil, K7PEH >> >> __ >> 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 w8dn.m...@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 phys...@mac.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] KAT500 tuning behavior when the load is impossible to match ?
No practical experience with the KAT500 but can tell you that, years ago, while guest operation at a contest station, a 160 meter vertical was strung up between a couple of the towers. The operator went in and successfully tuned the antenna to a 1:1 match and then loaded the KW amp to full output. He then went S&P to get warmed up but heard very little and could not work any of the few stations he did hear. We went out and discovered that the vertical wire had snagged on the ground rod! The tuner was manual but imagine the same principal applies. Yes, you can often get a "perfect" match but that may not count for much! Have often wondered if the earth worm population in that area ever recovered. Mike / W8DN On 4/2/2017 12:42 PM, Phil Hystad wrote: I got my second KAT500 tuner to use with my new backup rig and while setting up and testing and tuning with my two different antennas I made a mistake. I first observed the results displayed on the utility program operate page where the tuned SWR was 1:1 and the bypass SWR was something like 54:1. I immediately realized that something was not right and discovered that my coax cable was not switched to the antenna but rather my dummy load but the cable to the dummy load was disconnected (because I was moving things around). OK, fixed that little problem but I was curious about the behavior when the KAT500 tuner is faced with an impossible match. Does it give up? I assume it gives up but then I didn’t see anything to indicate that the tuning operation gave up. In fact, it seemed like it found a tuned LC solution but one that was matched with a bypass of 54:1. My first question: If KAT500 fails to find a valid solution does it report an error. I ask this because at times I have had red LED lights flashing on a failed tune but I did not have one this time. I am wondering if I missed the error report on the utility program. My second question: Is it possible that the KAT500 did resolve a tuned LC solution with basically 6 feet of coaxial cable unconnected with anything? Thanks, 73, phil, K7PEH __ 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 w8dn.m...@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
[Elecraft] KAT500 tuning behavior when the load is impossible to match ?
I got my second KAT500 tuner to use with my new backup rig and while setting up and testing and tuning with my two different antennas I made a mistake. I first observed the results displayed on the utility program operate page where the tuned SWR was 1:1 and the bypass SWR was something like 54:1. I immediately realized that something was not right and discovered that my coax cable was not switched to the antenna but rather my dummy load but the cable to the dummy load was disconnected (because I was moving things around). OK, fixed that little problem but I was curious about the behavior when the KAT500 tuner is faced with an impossible match. Does it give up? I assume it gives up but then I didn’t see anything to indicate that the tuning operation gave up. In fact, it seemed like it found a tuned LC solution but one that was matched with a bypass of 54:1. My first question: If KAT500 fails to find a valid solution does it report an error. I ask this because at times I have had red LED lights flashing on a failed tune but I did not have one this time. I am wondering if I missed the error report on the utility program. My second question: Is it possible that the KAT500 did resolve a tuned LC solution with basically 6 feet of coaxial cable unconnected with anything? Thanks, 73, phil, K7PEH __ 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