Hi Chris: I have a K3 and a BigIR. The problem with using a tuner with any SteppIR antenna is that you want want to change the SteppIR controller frequency to match your transmitter frequency which then changes the length of the antenna. As you know, this is how SteppIR maintains good SWR over the entire band. This happens automatically if you have the transceiver tracking option with your SteppIR. You do it manually if you don't have tracking So what next, do you then activate the ATU tune function on the K3 to readjust the internal tuner? It's just a little bit of additional complexity. This procedure would be especially troublesome on 80 meters where the antenna makes substantial length adjustments every 10KHz.
With the 80 meter coil option on the BigIR, you could see higher SWRs on 15 through 6 meters in the normal 1/4 wave mode. SteppIR recommends using the 3/4 wave mode for those bands. This may help. Before my K3, I had a FT1000D. I saw power rollbacks on 17 and 30 meters where my BigIR SWR is 2.0:1 and 1.6:1 respectively. So I used the tuner on those bands. I don't see any power rollback with my K3 so I don't use the tuner on those bands anymore. 73, Mike K2MK Chris Hembree wrote: > > When do you know if you need an ATU (KAT3). I just installed my Big > SteppIR Vert. > On 6m my swr is 1.9, 17m,20m,80m a swr of 1.6. > Thanks > Chris W7CTH > > > > > ______________________________________________________________ > 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 > > -- View this message in context: http://elecraft.365791.n2.nabble.com/SWR-tp5166250p5168126.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
