My first "radio book", the 1941 ARRL Radio Amateur's Handbook, mentions SWR in passing, but nearly everyone used open wire feed lines before WWII that, with their moderately high impedances (450 to 600 ohms), had rather low loss at any SWR one was likely to encounter. So Ham concerns with SWR were mostly academic and limited to the antenna "theory" discussions.
The need for shielding to minimize TVI and the huge amounts of very cheap "war surplus" coaxial cable after WWII changed the feed line landscape very quickly. The low impedance of that coax (50 ohms) meant that feed line losses were no longer insignificant although it took a number of years for coax to become the dominant feed line. By the 1950's QST was publishing designs for homebrewing an SWR Meter several times a year. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:[email protected]] On Behalf Of Fred Jensen Sent: Wednesday, April 27, 2016 1:35 PM To: [email protected] Subject: Re: [Elecraft] Feedline loss w/wo tuner Indeed! I don't remember when the acronym "SWR" crept into the Amateur lexicon, or we became concerned about it, but I'm pretty sure I was rapidly approaching "OT Status" when it happened. Early on, we link coupled to the final tank inductor and any reactance in the feedline just changed the resonant point which was adjustable of course. With the advent of the ubiquitous pi-network, we were just matching the impedance presented by the feedline to the plate impedance of the PA's [a couple of K ohms or so]. There is probably no single thing in a ham station more misunderstood [or mis-named] than "The Antenna Tuner." 73, Fred K6DGW Sparks NV Washoe County DM09dn ______________________________________________________________ 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 Message delivered to [email protected]
