Matt, Of course I don't question Don's technical stature, however "tuning the antenna" is a poor choice of explanation, and can give a false impression to those weak on the subject. Adding 'system' would have been a good move as you indicate. We tune where we measure.
-----Original Message----- From: Matt Maguire [mailto:[email protected]] Sent: Wednesday, 19 September 2012 3:35 PM To: vk4tux Cc: [email protected] Subject: Re: [Elecraft] KX3 ATU On 19/09/2012, at 2:48 PM, vk4tux <[email protected]> wrote: > Don, When you say "The ATU will tune the antenna to an acceptable > SWR", you are contradicting yourself, because as you rightly said the > tuner does not change the antenna feedpoint swr. It is clear from the context that Don meant the ATU will tune (ie. match) the antenna *system* to the radio, where the antenna system consists of the ATU, antenna and connecting feedline considered as a single unit. This of course does not mean that the VSWR is 1:1 everywhere within that system. The theory predicts that the measures VSWR will be constant along a *lossless* feedline. As you point out, practical feedlines do have losses. This will include I^2.R copper losses, but there can be losses from other sources as well, such as dielectric losses. Often such losses will be modelled as some sort of equivalent series resistance. 73, Matt VK2ACL= ______________________________________________________________ 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
