Thank you Matt,
> By "SWR graph", you mean the bar graph on the display of the KX3, right? If > so, are you sure it is set to measure VSWR rather than compression? No, I read it on the SWR of course. > > If you have initiated a tuning cycle with the KXAT3, and subsequently hold > the XMIT/TUNE button, and the radio reports a VSWR of 1.4, then this means > that the KXAT3 has not matched the impedance of the antenna system. This > would be the case, for example, is the KXAT3 was set in bypass mode. It is not on bypass mode. > > As Don notes below, if you put an SWR meter between the KX3 and the antenna, > then the KXAT3 will have no effect whatsoever on the reading of this meter > (after all, the KXAT3 is matching the impedance between the antenna system > and the PA stage inside the KX3, and has no effect all on the VSWR on the > section of transmission line between the KXAT3 and the antenna). I don't own an external swr meter so no, I didn't read between the radio and the antenna. > > If the SWR graph in your KX3 is set to read VSWR, and the KXAT3 has matched > the antenna ad reported a VSWR of 1.0, and you see the SWR graph jumping > around during transmit, then this could indicate flashover in the KXAT3. > Normally this should only happen if the antenna system is very far away from > 50 ohms. This is not likely to be the case here, if you indeed measured the > VSWR of the antenna system independently with the MFJ antenna analyser, and > found it only to be 1.4:1. This seems to be the case. So is it normal or not? Any idea how to fix it? Thanks again and I apologize for my English that apparently isn't good enough to explain what happened to me. Cheers. Luca > > 73, Matt VK2ACL > > > > On 19/09/2012, at 12:36 PM, luca de marinis <[email protected]> wrote: > >> Hi Don, I read the 1.4 SWR on my MFJ 259b then tuned with the KX3 atu to 1.0 >> >> On transmitting the swr graph showed peaks near to 2 and if I press the XMIT >> (tune) the reading is about 1.4 same as without ATU. >> >> Luca >> >> >> >> >> On Sep 18, 2012, at 7:12 PM, Don Wilhelm <[email protected]> wrote: >> >>> Lucia, >>> >>> You say that you had an SWR of 1.4, then used the ATU which lowered the >>> SWR to 1.0 >>> OK, That was on the KX3 display. >>> >>> Please tell us where you were reading the continued 1.4 SWR. The KX3 >>> display does not show the SWR during transmit - only during a TUNE. >>> The SWR shown externally to the KX2 ATU will not change, so if you are >>> using an external device, you will not see any change in the SWR reading. >>> >>> The KX3 ATU will reduce the SWR between the KX3 output PA and the input >>> to the KXATU3 to the value shown during on the KX3 display during a >>> TUNE, but the SWR between the KXATU3 and the antenna (as measured by an >>> external device) will not change. >>> >>> 73, >>> Don W3FPR >>> >>> On 9/18/2012 8:14 PM, luca de marinis wrote: >>>> Hi, >>>> >>>> I completed my KX3 #1715 few days ago and today I went to the park and >>>> using a Buddipole I tried to make some contacts. Buddipole swr was 1.4 on >>>> 20m so I used the ATU. It worked fine lowered the swr to 1.0 but then I >>>> transmitted I still could read a 1.4 swr. I moved up and down the band and >>>> tuned again and every time the ATU started from 9.9 and did the all cycle. >>>> Sometime couldn't go lower than 1.4. Sometimes after tuning the power was >>>> reduced to 2W >>>> >>>> Am I missing something. I did a search on the reflector but didn't show >>>> anything. >>>> >>>> Thank you in advance for your help >>>> >>>> >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
