To be clear, Rick, is the KAT3 in BYPASS when you adjust the Palstar tuner? It must be. Then, when you switch in the KAT3, you need to do a "tune" in which it will adjust its settings to a 1:1 SWR on the link between the KAT3 and the Palstar.
There's no advantage to having both tuners in the system. In normal use one or the other should be in bypass. Does the power jump happened when feeding a dummy load? If not, then it's certainly RF getting "loose" and triggering the power metering circuit in the K3. That usually happens at some critical power level, which fits with the SWR reported suddenly jumping above a specific power. Normally it's RF on the outside of the coax shield that finds its way back to the K3. Often, using a remote tuner will cure that sort of problem by providing some physical isolation between the K3 itself and the tuner in a separate box. I suspect you have something in the range of 60 feet of open line feeding your dipole. Such a feed line inverts the impedance. Since the dipole shows a relatively low impedance at the center, that means the end of the feed line in the shack has a very high impedance and high RF voltage. A 4:1 balun can help but it's no panacea in the presence of high RF voltages. Ron AC7AC -----Original Message----- Ken, Yes, I have the same problem. Using a 102' doublet, open wire to a 4:1 outside the shack. Works great everywhere above 160M but on 80 the SWR goes nuts over about 75 Watts. My workaround has been to not run over 75 Watts :-) Rick K6LE On 2/18/2012, at 1:40 , Ken <wa8...@gmail.com> wrote: > I am having trouble with my K3 tuner, the SWR jumps high when I turn it above 80 watts on 80m. > > At first I thought it was something outside but after replacing open wire feedline, balun, coax, I have come to the conclusion that the problem must be internal to the K3. > > The antenna is a 130' center fed dipole, fed with 45' of open wire to a 4:1 balun and then to the K3. It tunes easily and works okay on all the bands but on 80m, when I up the power above about 80 watts, the SWR jumps up and the K3 shuts down with "HI SWR. > > The problem does not happen with my old TS-440, nor does it happen when I bypass the internal K3 tuner and use an external Palstar AT2K tuner. > > I don't believe I had this problem when I bought the K3 last December but then I might not have run the power up all the way either. > > Thoughts? Am I missing something? Has anyone else had this same problem? > > Another thing I noticed (is it related?) is that when I tune the Palstar to 1:1 SWR, the K3 shows a 2+:1 SWR. If I use the K3 meter to tune the Palstar tuner, then the Palstar meter indicates a 2:1 SWR. > > Thanks, > > Ken WA8JXM ______________________________________________________________ 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
