Thanks, Carl I suppose all those wires helped to increase bandwidth.
Charlie K4OTV -----Original Message----- From: Carl [mailto:[email protected]] Sent: Saturday, December 06, 2014 10:20 AM To: Charlie Cunningham; 'Paul Christensen'; 'topband' Subject: Re: Topband: EZNEC 5.0 + Charlie, visualize a straight horizontal wire wire between two tall points; then slanting to vertical wires coming down to the common feed point. The Titanic had a multi wire T horizontal and vertical fed in the center. Considering its daytime range of 200-400 miles and up to 2200 at night with about 500W radiated from a 5KW spark it was pretty effective on 600M. Carl KM1H ----- Original Message ----- From: "Charlie Cunningham" <[email protected]> To: "'Paul Christensen'" <[email protected]>; "'topband'" <[email protected]> Sent: Saturday, December 06, 2014 12:41 AM Subject: Re: Topband: EZNEC 5.0 + > Not sure that I can picture just what you are describing, Paul. Even > though, I wasn't born until 1944, I've explored just about every type of > antenna and I've modeled an awful lot of them. > > Of course the typical inverted L is just a monopole that is bent over at > the top to reduce the required support height, and an inverted L with > elevated radials is just a ground-plane antenna that is bent over at the > top and the Tee equivalents just replace the single top wire with equal > and opposite wires at the top to extend the monopole to resonant length. > The Tee version does eliminate the modest residual horizontal component in > the far field that occurs with the inverted L configuration. Of course > antenna current is still fundamentally important - that's what does the > radiation! I do still have a matched pair of RF ammeters around here, but > these days we accomplish the equivalent measurement by measuring forward > power with our SWR bridges. There's still a fundamental I-squared x R > relation between power and antenna current, where R is the radiation > resistance of the antenna + copper losses. So, it's all the same thing, > really. I can't come up with the name of the antenna that you are > describing, because I can't quite picture it. > > 73, > Charlie, K4OTV > > > -----Original Message----- > From: Topband [mailto:[email protected]] On Behalf Of Paul > Christensen > Sent: Friday, December 05, 2014 11:23 PM > To: topband > Subject: Re: Topband: EZNEC 5.0 + > >> "What did they call the teens to 20's antenna that had multiple feeds >> coming > down from one end of the flatop to the other?" > > Both the "T" and the fanned inverted L were popular on 200m in 1910-1920 > just as the single-wire Inverted L is today on 160m. Back then, ops were > obsessed with maximum antenna current but radiation resistance didn’t > enter into the discussions until the mid '20s. By the mid 20s when CW > took over, much less attention was paid to antenna current as a station > performance metric. > > During the spark era, ops would keep adding horizontal wires to the flat > top fans until the line current reached diminishing returns. We typically > see > 5-6 wires wide-spread in old station photos. Then, separate wires would > connect to the flat top and extended down a common point where it became a > single-wire feeder. > > Paul, W9AC > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2015.0.5577 / Virus Database: 4235/8690 - Release Date: 12/06/14 > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
