Tom, W0TOM wrote: > May I make a radical suggestion? Use the internal K3 > antenna tuner! Now I know that most transceivers have > internal tuners that will operate well only up to 3:1 swr. > The K3 tuner is rated much higher than that. Indeed, > I was very surprised how well it works here in my station > with my 135' foot dipole with 450 ohm ladder line and a > balun. > I highly recommend that one should consider the K3 tuner. > It's a winner.
------------------------------ That's true of all the Elecraft tuners, AFAIK except the KX1's optional internal ATU. Perhaps it speaks to Wayne's roots as a QRP enthusiast who loves operating portable that the Elecraft tuners all have a very good matching range. The KX1 has a slightly smaller range simply because he ran out of room to squeeze any more toriods into the tiny space allotted to the tuner. Even so, it'll load up most ad-hoc random wires and doublets. That said, the limitation on all tuners is what maximum currents (when feeding very low impedance loads) and what maximum voltages(when feeding high impedance loads) they can handle without parts failing. The smaller the physical size of the tuner, the greater these limits, especially on voltages. Anyone who has messed with a Tesla coil can attest to how high voltage RF behaves. Nothing can replace lots of physical separation between components, and that's not possible in a physically small tuner. A little attention to avoiding a "voltage loop" at the rig end of the feeder will avoid that extreme condition. Although baluns can be very unpredictable (and sometimes lossy) at extreme impedances, many Hams have successfully used a 4:1 balun, like the Elecraft BL2, to reduce the impedance at the rig to something the ATU can more easily handle. That has the same effect as adding or subtracting feed line or adjusting the length of the antenna, and it's obviously easier to do. Ron AC7AC ______________________________________________________________ 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
