KAT500 tuning behavior when the load is impossible to match ?
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KAT500 tuning behavior when the load is impossible to match ?
 
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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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KAT500 tuning behavior when the load is impossible to match ?
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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:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KAT500 tuning behavior when the load is impossible to match ?
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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 <[hidden email]> 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:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Electricity and worms [was: KAT500 tuning behavior when the load is impossibleto match ?]
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FWIW back in the 80s, I had installed a new ground plate for the shack and
wanted to ensure that it really was the best ground possible. I used a trick that was used by the telecom people, where they connected the local exchange battery across two plates and blew off all the crud. 50 volts at many hundreds of amps did the business. My way was to connect my ground plate to the incoming 240 volt supply main, via a MCB and each time the MCB tripped, I substituted bigger one until I had no more larger values. ISTR I got to 40 amps and settled for that. I had obviously made sure that no person or animal could get near the area whilst the power was on, but I was quite surprised to see how many earthworms had scuttled their way to the surface. <grin> 73, Alan. G4GNX -----Original Message----- From: Phil Hystad Sent: Sunday, April 2, 2017 6:31 PM To: Mike Rhodes Cc: Elecraft Reflector Subject: Re: [Elecraft] KAT500 tuning behavior when the load is impossibleto 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 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KAT500 tuning behavior when the load is impossible to match ?
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In reply to this post by Phil Hystad-3
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KAT500 tuning behavior when the load is impossible to match ?
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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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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