Although the RMS voltage is pretty high. The peak voltage is higher especially if SWR isn't 1:1 along the transmission line.
It could easily be above 1Kv and causing arcing. 73 jim ab3cv On Fri, Sep 27, 2019 at 10:35 AM Michael Walker <[email protected]> wrote: > Like others have said > > Even though your analyzer says the antenna is ok, that is only one part. > It can still be part of the problem at 1500 watts and if memory serves me > well, that is about 275V (RMS) at 50 ohms. > > Something could be breaking down at that voltage so a good visual > inspection would help. Look for arcing at each connector, Ununs, Baluns, > etc. > > Mike va3mw > > On Fri, Sep 27, 2019 at 9:18 AM Bob McGraw K4TAX <[email protected]> > wrote: > > > Check for burn marks or carbon traces, both on the inside and outside, > of > > the SO-239 connectors. These may look good with the antenna analyzer but > > fail under power. > > > > I've also had PL-259's arc from center pin to shell on the inside. These > > required removal/ disassembly of the coax in order to actually find the > > fault. > > > > In all cases, once a flashover occurs, replacement of the connector is > the > > only solution. > > > > Bob, K4TAX > > > > > > Sent from my iPhone > > > > > On Sep 27, 2019, at 6:00 AM, John Langdon <[email protected]> > wrote: > > > > > > If it also happens with a dummy load, and the antenna analyzers shows > > the same graph as before for R, X, then it is likely one of the > connectors > > between the KPA1500 output and the antenna. The one such problem I had > was > > old jumper I had put in to add an SWR bridge/monitor. It looked okay, and > > was finger tight, but when I replaced it in an A/B test, the problem went > > away. > > > > > > The other time, the antenna had changed its impedance curve, but was > > still 'okay' and the tuner was trying to retune for it. > > > > > > 73 John N5CQ > > > > > > > > > -----Original Message----- > > > From: [email protected] < > [email protected]> > > On Behalf Of Jim Brown > > > Sent: Friday, September 27, 2019 4:19 AM > > > To: [email protected] > > > Subject: Re: [Elecraft] KPA-1500 failing on 160...AGAIN! > > > > > >> On 9/26/2019 10:26 PM, Peter Dougherty wrote: > > >> Any idea where to start looking here? > > > > > > And if it's a vertical, what about the radial system? > > > > > > 73, Jim K9YC > > > ______________________________________________________________ > > > 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 > > Message delivered to [email protected] > > > ______________________________________________________________ > > > 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 > > > Message delivered to [email protected] > > > > > > > > > ______________________________________________________________ > > 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 > > Message delivered to [email protected] > > > ______________________________________________________________ > 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 > Message delivered to [email protected] > ______________________________________________________________ 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 Message delivered to [email protected]
