But why is the SWR varying like that? Is it wind moving the antenna or ladder line around, maybe close to something metal? Is it bad connection? Is the balun saturating or heating up (unlikely at 10W, but then I don't know the details of your balun)?
With the power, it is important to have solid connections and decent gauge wire, and as Don says, a fuse (preferably an automotive style blade fuse) in order to minimise transient voltage drops. Are you running anything else off the battery? 73, Matt VK2RQ On 31/08/2013, at 4:37 AM, "Arno Dienhart" <a...@broadweave.net> wrote: > Hi Matt, > Maybe I gave a wrong impression with my statement of "SWR never higher than > 1.3". Usually, SWR is at 1.0 and only at rare instances do I see 1.3. What I > wanted to express is that SWR should not be the cause of the issue. > > I have not observed the display at the very moment of power switching back > and will look for it next time. > > 73, > Arno K7RNO > > -----Original Message----- > From: Matt VK2RQ [mailto:matt.vk...@gmail.com] > Sent: Friday, August 30, 2013 12:32 > To: Arno Dienhart > Cc: <Elecraft@mailman.qth.net> > Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W > > Hi Arno, > > I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I > normally run 10W, and haven't observed problems with the rig switching back > to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower > voltage, the rig needs to draw more current to maintain a particular power > output. Have you observed the display on the rig at the moment it switches > back to 5W? Does it display any warning such as Hi Curr(ent)? > > I am a bit concerned about the fact that you report an SWR of 1.3 *after* > tuning. I find the SWR is already low on the bands of interest, and after > tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up > to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a > bit concerned that something may be amiss with your antenna system. > > 73, Matt VK2RQ > > On 31/08/2013, at 3:50 AM, "Arno Dienhart" <a...@broadweave.net> wrote: > >> I would like to come back to this topic with an update after still >> experiencing the same issue. >> >> >> >> I now use my ZS6BKW with a 1:1 current balun between the twin line and >> the coax. I have tried a 70' and a 30' length of coax to the rig. If >> you think it will solve the problem, I might even try a 5' length and >> smolder in the sun! >> >> My battery shows 11.4 V during transmit on the KX3's PS meter. >> >> SWRs are never higher than 1.3:1 after tuning. >> >> PA temperatures are never very high (sitting in the shade). >> >> >> >> I have tried lower W settings, like 8W, which, on some bands, hold for >> a while. On other bands, they too revert back to 5W. >> >> >> >> So, if this is all normal, I don't understand why the KX3 is rated at 10W. >> Or asking in a different way: what needs to be present to keep the >> transmitter from reverting down from 10W, and how can I achieve that >> state with my setup? >> >> >> >> Please keep in mind that I don't have any antenna analyzing >> instruments other than what the KX3 provides. >> >> >> >> Thank you and 73, >> >> Arno K7RNO >> >> ______________________________________________________________ >> 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 > > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
